lOKTOS, CAL.
 
 THE 
 
 ARTIST'S GUIDE 
 
 AND 
 
 MECHANIC'S OWN 
 
 EMBRACING 
 
 THE PORTION OF CHEMISTRY APPLICABLE 
 
 TO THE 
 
 MECHANIC ARTS, 
 
 WITH 
 
 ABSTRACTS OF ELECTRICITY, GALVANISM, MAO 
 NETISM, PNEUMATICS, OPTICS, ASTRONOMY, 
 
 AND 
 
 JVIECHAMCAL PHILOSOPHY, 
 
 ALSO 
 
 MECHANICAL EXERCISES 
 
 IN 
 
 !HON. STEEL, LEAD, ZINC, COPPER, AND TIN SOLDERING 
 
 AND 
 
 A VARIETY OF USEFUL RECEIPTS, 
 
 EXTENDING 
 
 TO EVERY PROFESSION AND OCCUPATION OF LIFE ; 
 
 PARTICULARLY 
 
 DYEING, SILK, WOOLLEN, COTTON, AND LEATHER 
 
 BY JAMES PILKINGTON. 
 
 BOSTON: 
 CHASE, NICHOLS AND HILL. 
 
 No. 43 Washington St.
 
 Eiitt>ri*i, according to the Act of (..'onjjress. in tip year IS41, 
 
 BY ALEXANDER V. RLAKE, 
 Fn Ais clerk's office of the ilistricl court of vho southern district of 
 
 New York.
 
 PREFACE. 
 
 MECHANICS generally, having risen from families 
 in the more humble stations of society, are not much 
 favored with school education. Yet, in their case 
 may be seen what is common in the allotments of 
 Providence, that an evil is attended with a correspond- 
 ing benefit. Thus, if poverty obliges many a youth 
 to resort to the workshop for means of subsistence, 
 instead of spending his time under tutors in obtain- 
 ing from books the elementary instruction usually es- 
 teemed necessary to usefulness in life, it is a fact well 
 known, that most mechanical pursuits are found 
 favorable to mental developement. The fixtures of 
 a mill, in multitudes of cases, seem to have answered 
 about the same purpose in this respect, as the labora- 
 tory of the chemist, or the philosophical apparatus of 
 the college professor. Instances have been frequent 
 that the unlettered boy has risen, step by step, guided 
 by his own energies, till he became distinguished for 
 science and for inventions to bless the whole range 
 of society. And it is believed, that no class in the 
 community is more characterized than mechanics for 
 the best of all possible endowments, the capability 
 and habit of thinking for themselves.
 
 n PREFACE. 
 
 The admission of this truth renders it desirable, 
 that all possible facilities be placed within the reach 
 of this most respectable and valuable portion of out 
 community. Indeed, it is nearly as certain as mathe- 
 matical demonstration, that if facilities are placed 
 within their reach, the result will be auspicious. 
 Such persons do not often neglect their opportunities 
 for improvement. The young collegian may some- 
 times exhaust his paternal bounty, knowing or real- 
 izing but little of its value ; but, the young mechanic 
 looks upon his time and his means for improvement 
 as better than money, inasmuch, as on them alone he 
 depends for means of subsistence and the hope of fu- 
 ture distinction. 
 
 The author of the following work has received his 
 education in the manner described not under aca- 
 demical supervision in classic halls ; but amidst the 
 ponderous wheels of powerful machinery, where he 
 was his own teacher. And, many a time would it 
 have saved him immense labor in his pursuits could 
 he have had access to a few well made books eluci- 
 dating the mysteries of his trade ; it would have 
 bouyed up his wearied spirit and led him on to re- 
 newed exertions in the attainment of knowledge. 
 He has spent years in study which might have been 
 saved for other objects. To furnish his brother me- 
 chanics with such a desideratum, the following pages 
 have been prepared. If the work is not as good as 
 it might be, he trusts it is as free from faults as the 
 nature of the case can well admit. He has embraced 
 a wide range, and was obliged, of course, to be con- 
 cise. The mechanic has neither the ability to pro
 
 PREFACE. Vil 
 
 sure voluminous and elaborate treatises ; nor, if pro- 
 cured, the leisure to study them. 
 
 From habits of intimacy with hundreds and per- 
 haps with thousands of mechanics, he is well per- 
 suaded, that the present effort to promote their inter- 
 ests will be duly appreciated by them. And there is 
 scarcely a laboring man in the community, whatever 
 be his own particular trade, but what will find much 
 in the Mechanic's Own Book -suited to his own indi- 
 vidual wants. An examination of it will convince 
 any one of this fact. 
 
 Mechanics and artists have occasion to be proud oi 
 many names among their brethren. Roger Sherman, 
 oil:? of the most extraordinary men of Connecticut, 
 in early life, was an humble shoe maker. The Rev. 
 Thomas Baldwin, D. D., for many years, the vener- 
 able father as it were, of the Baptist denomination in 
 this country, is said to have been a hard laboring 
 blacksmith. One of the acting governors of the 
 State of Massachusetts, now living in affluence and 
 surrounded by men of eminence, when a boy was 
 poor, and an apprentice in a printing office. Other 
 cases of a similar sort might be named ; and the story 
 of Franklin is too familiar to my readers to need reci- 
 tal. The late Samuel Slater came to America with 
 a few pounds only in his pockets ; blithe lived to see 
 through his agency some of the most important rela- 
 tion? and inter* sts of society entirely changed ; and 
 died a man of great wealth. And who can tell all 
 the important results now enjoyed by the world, that 
 may be traced back to the untiring genius of Robert 
 Fulton, once an itinerant painter 1 Or to the
 
 riii PREFACE. 
 
 fatigable Oliver Evans, whose first studies were pur- 
 sued after the hours of daily toil, in a wheelwright's 
 shop by the light of his burning shavings. And 
 Richard Arkwright, too, the founder of cotton spin- 
 ning by machinery was bred to the trade of a barber, 
 and has obtained one of the most endurable monu- 
 ments to his genius the world ever raised. Indeed, 
 it would fill a volume to give notes of all the me- 
 chanics that have acquired a praiseworthy fame. 
 
 In making the above allusions, it may not oe in- 
 appropriate to mention the names of two other indi- 
 viduals who have obtained an enviable reputation. 
 The first is Thomas Blanchard, extensively known 
 in the United States for his mechanical skill, and now 
 employed in the city of New York endeavoring to 
 perfect a new invention. He will be remembered for 
 ages to come for the benefits to society from his un- 
 tiring genius. The second is E. Burritt, denomina- 
 ted, by governor Everett, the learned blacksmith, a 
 resident of Worcester, Massachusetts. The appella- 
 tion is a most just one. He is not thirty years-of age, 
 and labors eight hours daily, at his trade, yet he has 
 learnt to read fifty different languages. Were the 
 fact not supported by good authority, it would bt in- 
 credible ! Nor is Mr. Burritt satisfied with his pre- 
 sent attainments; he continues to devote all his lei- 
 sure time to study that is, all not spent in manual 
 labor and sleep. Apparently he has laid the founda- 
 tion only of the superstructure to be erected thereon, 
 What an example is his to the young mechanics of 
 our country !
 
 ARTIST'S GUIDE, 
 
 AND 
 
 MECHANICS' OWN BOOK. 
 
 CHEMISTRY. 
 
 OF CHEMICAL NOMENCLATURE. 
 
 FROM the revival of learning, after the fall of the Ro- 
 man empire, to nearly the close of the seventeenth cen 
 tury, Chemistry was chiefly confined to those who fol- 
 lowed it with alchemical views. Those persons, many of 
 whom knew that they were deceiving their patrons, 
 while others were desirous to conceal their self-delusion, 
 or to create admiration by the appearance of having 
 done much, were anxious to give every product of their 
 laboratories a mysterious, extraordinary, or unintelligible 
 name. As they did not act in concert, the same prepa- 
 ration obtained very different names ; and, as they were, 
 with few exceptions, as eminent for ignorance as effron- 
 tery, and carried on their operations at random, they 
 examined but superficially the substances which they 
 undertook to denominate, and knew not to what they 
 were indebted for their leading properties. Such names 
 as horn moon, mercury of life, the wonderful salt, the 
 satt with many virtues, form but a small specimen of 
 pr-idigious number, equally inappropriate and ridiculous. 
 ll-nce, when the dreams of alchemy were broken by the 
 dawn of a more enlightened day when men who had 
 tha promulgation of truth only for their object, became 
 rbemists, from a persuasion cf the advantages which the 
 
 2005123
 
 10 CHEMISTRY. 
 
 cultivation of that science would afford to mankind, they 
 found it difficult to unravel the confusion which the 
 misnomers of their predecessors had created. In propor- 
 tion as discoveries were multiplied, the want of a regular 
 arid appropriate nomenclature increased, and formed a 
 strong bar to the general diffusion of a taste for chemical 
 researches. A few innovations, which were made hy 
 single individuals, in order to accommodate the language 
 of chemistry to the improved state of knowledge, served 
 only to show how much was still wanted. It is per 
 fectly obvious that names founded upon a mistaken view 
 of the properties of things, tend to the propagation of 
 erroneous opinions, and that, when a vast number of sub- 
 stances aie designated at random, without any connection 
 in names, although nearly related in composition, the 
 mere effort of memory to recollect these names, will 
 exceed the effort which ought to be required for the ac- 
 quisition of a science. Towards the close of the last 
 century, therefore, several eminent French chemists 
 determined to take a comprehensive view of the subject, 
 and to remodel the whole system of chemical nomencla- 
 ture a task which they completed in 1797. Their 
 object was to reject all the old names which were known 
 to convey false ideas, 'out to preserve those which were 
 not of this class, and to which custom had given a cur- 
 rency, scarcely and not usefully to be checked. They 
 at the same time introduced new terms, of appropriate 
 derivation ; and the method of forming compound terms, 
 so as to indicate the composition of compound bodies, 
 was pointed out. This system of nomenclature possessed 
 so much merit, that the adoption of it soon became gene- 
 ral in France ; and from thence, it spread with great 
 rapidity to other countries, where it was received either 
 ei.^irely, 01 with such improvements as experience war- 
 raiiied. The objections which have been urged against 
 it are futile; they have chiefly amounted to this, that 
 it is not absolutely perfect, and will, by the progress of 
 disci.v?ry, hereafter require to be modified. On the con- 
 trary, a high eulogium on its. value and opportune
 
 CHEMICAL NOMENCLATURE. 
 
 11 
 
 establishment is conveyed by the opinion of several emi- 
 nent chemists that the present state of chemistry could 
 not be communicated, much less remembered, by the 
 language previously in use. 
 
 The following table will exhibit the most important 
 changes of terms which have been made, and more par- 
 ticular details will occur, as an account of each sub- 
 stance gives occasion : 
 
 Old names. 
 
 New names 
 
 Acetous Salts, ... 
 
 Acetates. 
 
 Acid of vitriol, phlogisti- 
 cated, 
 
 [ Sulphurous acid. 
 
 of alum ... 
 
 1 
 
 of vitriol - 
 vitriolic ... 
 
 >Sulphuric acid. 
 
 of sulphur 
 
 j 
 
 of nitre, phlogisti- 
 cated, . 
 
 1 Nitrous acid. 
 
 of nitre, dephlogisti- 
 
 \ 
 
 cated, 
 
 > Nitric arid. 
 
 of saltpetre - - 
 
 ) 
 
 of sea-salt 
 
 [ Muriatic acid. 
 
 marine ... 
 
 ) 
 
 dephlogisticated ma- 
 rine 
 
 | Oxygenized muriatic acid. 
 
 aerial .... 
 
 ^ 
 
 of chalk - - - 
 
 
 cretaceous - - 
 calcareous - - 
 
 >Carbonic acid. 
 
 of charcoal - - 
 
 
 mephitic - - - 
 
 J 
 
 of spar or fluor 
 
 > Fluoric acid 
 
 sparry ... 
 
 j 
 
 of borax - - - 
 
 Boracic acid. 
 
 of arsenic 
 
 Arsenic acid. 
 
 of tungsten 
 of wolfram - - 
 
 | Tungstic acid. 
 
 of molybdina 
 
 Molybdic acid.
 
 12 CHEMISTRY. 
 
 Old names 
 
 New naxiea. 
 
 Acid of apples - - 
 
 Malic acid. 
 
 of sugar - - 
 
 | 
 
 sa ccharine - - 
 
 > Oxalic acid. 
 
 of wood sorrel 
 
 i 
 
 of lemons - - 
 
 Citric acid. 
 
 of cream of tartar 
 
 Tartaric acid. 
 
 of benzoin 
 
 Benzoic acid. 
 
 of galls ... 
 
 Gallic acid. 
 
 of amber - - - 
 
 Succinic acid. 
 
 of ants - 
 
 Formic acid. 
 
 of cork ... 
 
 Suberic acid. 
 
 of phosphorus, phlo- 
 gisticated --- 
 
 | Phosphorus acid. 
 
 of phosphorus, de- 
 phlogisticated - - 
 
 ( Phosphoric acid. 
 
 of silk worms 
 
 Bombic acid. 
 
 of fat - 
 
 Sebacic acid. 
 
 sedative 
 
 Boracic acid. 
 
 of lac - - 
 
 Laccic acid. 
 
 of milk - - - 
 
 Lactic acid. 
 
 saccholactic - - 
 of sugar of milk 
 
 | Mucous acid. 
 
 Air - .... 
 
 Gas.* 
 
 dephlogisticated > 
 
 VJclo. w 
 1 
 
 pure - - - - 
 
 impure or vitiated ) AT ., 
 
 burnt - - - - ^itrogen gas, or azote, or 
 - phlogisticated - ) azotic gas. 
 
 inflammable - - Hydrogen gas. 
 
 - marine acid - - Muriatic acid gas. 
 
 dephlogisticated ma- ) Oxygenized muriatic arid 
 
 rine acid \ gas. 
 
 * The term gas is now used as a general name fcr all kinds of 
 ir, except atmospheric air.
 
 CHEMICAL NOMENCLATURE. 
 
 Old names. 
 Air hepatic ... 
 
 fetid of sulphur - 
 
 fixed ... 
 
 solid, of Hales 
 
 alkaline ... 
 
 Alga roth, powder of 
 
 Alkalies, fixed - - - 
 Alkali, volatile - - - 
 concrete volatile 
 
 Alkalies, caustic - - 
 
 Alkalies effervescent, or 
 not caustic, or aerated, 
 or mild. 
 
 Alkali vegetable - - 
 mineral - - - 
 
 prussian 
 
 Alum 
 
 Antimony, crude - - 
 diaphoretic - j 
 
 Aquafoitis .... 
 Aqua-regia - - - - 
 Aqua ammonia pura 
 Argil, or argillaceous earth, 
 
 Barilla 
 
 Benzoar mineral - - - 
 Black lead .... 
 Blue, Prussian - - - 
 Borax - .... 
 Butter of antimony - - 
 Calces, metallic - - - 
 Caustic, lunar ... 
 
 New names. 
 Sulphuretted hydrogen ga^ 
 
 Carbonic acid gas. 
 
 Ammoniacal gas. 
 
 White oxide of antimony bj 
 the muriatic acid. 
 
 Potash and soda. 
 
 Ammonia. 
 
 Carbonate of ammonia. 
 
 Pure alkalies, or those de- 
 prived of carbonic acid. 
 
 Alkaline carbonates, or alka 
 lies combined with carbo 
 nic acid. 
 
 Potash.* 
 
 Soda. 
 
 Prussiate of potass. 
 Sulphate of alumine and 
 
 potass. 
 
 Sulphuret of antimony. 
 White oxide of antimony 
 
 by the nitric acid. 
 Nitric acid of commerce. 
 Nitro-muriatic acid. 
 Ammonia. 
 Alumine. 
 
 Carbonate of soda. 
 Oxide of antimony. 
 Hyper-carburet of iron. 
 Prussiate of iron. 
 Borate of soda. 
 Muriate of antimony. 
 Metallic oxides. 
 Fused nitrate of silver. 
 
 The potash of commerce, when purified, is now called potasa 
 2
 
 14 CHEMISTRY. 
 
 Old names. 
 
 JVejo names. 
 
 
 ( White oxide of lead by -he 
 
 "" 
 
 I acetous acid. 
 
 Ceruse ot antimony - - 
 
 ( White oxide of antimony by 
 I precipitation. 
 
 Chalk 
 
 Carbonate of lime. 
 
 Charcoal, pine - - - 
 
 Carbon. 
 
 Jinnabar ..... 
 
 ( Red sulphuretted oxide of 
 
 
 I mercury. 
 
 Colthothar of vitriol - 
 
 ( Red oxide of iron, by the 
 I sulphuric acid. 
 
 Copper, acetated - - 
 
 Acetate of copper. 
 
 Copperas, green ... 
 
 Sulphate of iron. 
 
 blur 
 
 ^c n 
 
 
 
 Cream of tartar - - - 
 Earth, calcareous - 
 
 Supertartrate of potass. 
 Lime. 
 
 aluminous 
 of alum ... 
 
 > Alumine. 
 
 siliceous ... 
 
 Silex. 
 
 ponderous - - 
 
 Barytes. 
 
 magnesian - - 
 muriatic - - - 
 
 | Magnesia. 
 
 Egg, white of - - - 
 
 Albumen 
 
 Elastic gum - - - - 
 Indian rubber - - - 
 
 > Caoutchouc. 
 
 Emetic tartar ... 
 
 ( Antimoniated tartrate o* 
 
 
 I potass. 
 
 C 1 __ _ 
 
 Volatile oil 
 
 Ethiops martial - - - 
 
 Black oxide of iron. 
 
 irunr*r*"i1 
 
 ) Black sulphuretted oxide ol 
 
 
 Flowers, metallic - - 
 
 Sublimated. metallic oxides. 
 
 f^C -11 
 
 on * i -. 
 
 Tltiors 
 
 Fluates. 
 
 Glass of bismuth - - 
 
 Vitreous oxide of bismuth. 
 
 Glue or jelly ... 
 
 Gelatine. 
 
 Glutinous matter - - 
 
 Gluten. 
 
 Gypsum ..... 
 
 Sulphate of lime. 
 
 
 Sulnhurets.
 
 Old names. 
 
 Heat, latent, or matter of 
 heat 
 
 , 
 Hermus mineral - - 
 
 CHEMICAL NOME]\ 7 CLATURE. 15 
 
 New names. 
 r a j or j c 
 
 Red sulphuretted oxide of 
 
 Lapis infernalis 
 Leys 
 
 r of 
 
 antimny . 
 
 Fused nitrate of silver. 
 Solutions of alkalies. 
 
 Solutions of siliccous P tash - 
 
 Litharge, or semi -vitreous 
 
 oxid?oflead. 
 
 Liver of sulphur, alkaline Sulphuret of potash. 
 Liver of sulphur, calcareous Sulphuret of lime. 
 Muriate of silver. 
 ( Oxide of bismuth 
 j nitric acid. 
 Precipitated oxide of lead. 
 Carbonate of magnesia . 
 
 - black - - Black oxide of manganese. 
 Masticot ...... Yellow oxide of lead. 
 
 Matter, amylacious - - Fecula, or starch. 
 Mephitis ------ Nitrogen. 
 
 Minium ------ Red oxide of lead. 
 
 Luna cornea 
 
 ,, . , e , . ,, 
 Magistery of b.smuth 
 
 - of lead - 
 Magnesia 
 
 by the 
 
 Mother waters 
 
 . 
 Saltpetre - - 
 
 Nitres - - - 
 Oils, fat 
 
 essential - 
 - ethereal - 
 
 of tartar per 
 
 quium 
 
 deli- 
 
 Deliquescent saline residues. 
 Nitrate of potash. 
 
 Nitrates. 
 Fixed oils. 
 
 -.T , ... ., 
 Volat.le oils, 
 
 carbonate of 
 
 Solution of 
 
 potash. 
 
 Phlogiston, an imaginary principle, adopted by Stahl 
 and his followers, to account for the phenomena of com- 
 bustion Its existence having never been proved, it has 
 no name in modern science.* 
 
 * In jjeneral, the- works in which it is used, may he understood 
 oy substituting tho term " hydrogen," instead of it ; and by 
 * dephlofristicaled," understanding free from hvdro^en.
 
 CHEMISTRY. 
 
 Old names. 
 
 Phosphoric salts 
 Plumbago - - 
 
 Precipitate, red 
 
 -- per se - 
 Princip'i, astringent 
 --- tanning 
 --- acidifying 
 
 --- inflammable, identical with Phlogiston. 
 Pj \'f t '>{ copper - - Sulphuret of copper. 
 
 --- . . \nartial 
 
 /.,... 
 ---- factitious - 
 
 New names. 
 
 - Phosphates. 
 Hyper-carburet of iron. 
 
 ( Red oxide of mercury bj 
 | the nitric acid. 
 Red oxide of mercury by fire 
 
 - Gallic acid. 
 
 - Tannin. 
 
 - Oxygen. 
 
 c 
 01 
 
 Kcr /.*.s of a metal 
 
 kusl of copper - - - 
 
 of iron - - - 
 
 Saifron of mars - - - 
 Sal ammoniac - - - 
 poly ch rest - - - 
 Salt, common or sea 
 febrifuge of Sylicius 
 
 Salt, fusible of urine - 
 
 Salt glaubers - - - 
 
 epsom --- - 
 
 of Sorel - - - 
 
 of wormwood 
 
 vegetable - - - 
 
 sedative - - - 
 
 Sthal's sulphureous 
 
 Selenite 
 
 Spar, calcareous - - 
 
 fluor - - - - 
 
 ponderous - - 
 
 Spirit, ardent ... 
 
 of nitre - - - 
 
 of nitre, fuming - 
 
 of salt .... 
 
 of sal ammoniac 
 
 - Red sulphurated oxideofarsemc 
 The metal in a state of purity 
 
 - Green oxide of copper. 
 
 - Carbonate of iron. 
 
 - Red oxide of iron. 
 
 - Muriate of ammonia. 
 
 - Sulphate of potass. 
 
 - Muriate of soda. 
 Muriate of potass. 
 
 ( Phosphate of soda and am- 
 \ monia. 
 Sulphate of soda. 
 
 - of magnesia. 
 
 - Super-oxolate of potass. 
 
 - Carbonate of potass. 
 
 - Tartrate of potass. 
 
 - Boracic acid. 
 
 - Sulphate of potash. 
 
 - Sulphate of lime. 
 
 - Crystallized carbonate of lime 
 
 - Fluate of lime. 
 
 - Sulphate of barytes. 
 
 - Alcohol. 
 
 - Nitric acid. 
 
 - Nitrous acid. 
 
 - Muriatic acid. 
 
 - Ammonia.
 
 CHEMICAL NOMENCLATURE. 1*7 
 
 Old names. New names. 
 
 Spirit of vitriol .... Sulphuric acid. 
 -- of wine - ... Alcohol. 
 Spiritus rector - - - - Aroma. 
 
 Sublimate, corrosive - j Cor muriate f mep 
 
 Sugar of lead .... Acetate of lead. 
 
 Sulphur, alkaline liver of - Sulphuret of potass, soda, &c, 
 
 - metallic liver of 
 
 Tartar ...... Super-tartrate of potass. 
 
 _ . ( Antimoniated tartrate of po- 
 
 - vitriolated - - - Sulphate of potash. 
 Tartars ...... Tartrates. 
 
 Tinctures, spirituous - - Resins dissolved in alcohol. 
 Turbith mineral - - ^ Yellow oxide of mercury b ? 
 
 { sulphuric acid. 
 Verdigris, or rust of cop-S 
 
 PCr ' exposed to t " he >Green oxide of copper. 
 
 air - - - J 
 f ., , C Acetate of copper mixed 
 
 - of the shops | with oxide. * 
 
 _ ,. ... , C Crystallized acetate of cop- 
 
 Vinegar, distilled - - - Acetous acid. 
 - radical - - - Acetic acid. 
 Vitriol, blue or roman - Sulphate of copper. 
 
 green 
 martial 
 
 > 
 
 > 
 
 - white .... - of zinc. 
 
 Vitriols ...... Sulphates. 
 
 Water, acreted or acidu- ( Water impregnated with 
 lated. $ carbonic acid. 
 
 _ , ( Water impregnated with 
 
 - hepatic J sulphuretted hydrogen. 
 
 2 B
 
 18 CHEMISTRY. 
 
 CHEMICAL TERMS EXPLAINED. 
 
 To the preceding view of chemical nomenclature, the 
 following explanations of terms will not perhaps be an 
 unacceptable addition. 
 
 Affinity, (a proximity of relationship.) The term af- 
 finity is used indifferently with attraction. See Attrac- 
 tion. 
 
 Air. This term, till lately, was used as the generic 
 name for such invisible and exceedingly rare fluids as 
 possess a very high degree of elasticity, and are not con- 
 densible into the liquid state by any degree of cold 
 hitherto produced; but, as this term is commonly em- 
 ployed to signify that compound of aeriform fluids which 
 constitutes our atmosphere, it has been deemed advisable 
 to restrict it to this signification, and to employ as the 
 generic term, the word GAS, for the different kinds of 
 air, except what relates to our atmospheric compound. 
 The atmosphere may be said, in general terms, to consist 
 of oxygen and nitrogen ; but atmospheric air, even when 
 purest, always contains a small proportion of other prin 
 ciples. Murray states its exact composition as follows : 
 
 By measure. By weight. 
 
 Nitrogen gas, - 77.5 - - - 75.55 
 
 Oxygen gas, - 21.0 - - - 23.32 
 
 Aqueous vapour, 1.42 - - 1.03 
 
 Carbonic acid gas, .08 - - - .10 
 
 100.0 100.0 
 
 Alchemy. That branch of chemistry which relates 
 to the transmutation of metals into gold ; the forming a 
 panacea or universal remedy, an alcahest, or universal
 
 CHEMICAL TERMS EXPLAINED. 19 
 
 menstruum, an universal ferment, and many other absurd- 
 Hies. 
 
 Alchemist. One who practises the mystical art oi 
 alchemy. 
 
 Alkali, or ant-acid. Any substance which, when 
 mingled with acid, produces fermentation. (See Alkalies.) 
 
 Alloy. 1. Where any precious metal is mixed with 
 another of less value, the assayers call the latter the 
 alloy, and do not in general consider it in any other point 
 of view, than as debasing or diminishing the precious 
 metal. 
 
 2. Philosophical chemists have availed themselves of 
 this term, to distinguish all metallic compounds in gen- 
 eral. Thus brass is called the alloy of copper and zinc ; 
 bei!-metal, an alloy of copper and tin. 
 
 Every alloy is distinguished by the metal which pre- 
 dominates in its composition, or which gives it its value. 
 Thus English jewelry, trinkets, are ranked under alloys 
 of gold, though most of them deserve to be placed under 
 the head of copper. When mercury is one of the com- 
 ponent metals, the alloy is called amalgam. Thus we 
 have an amalgam of gold, silver, tin, &c. Since there* 
 are about thirty different permanent metals, independent 
 of those evanescent ones that constitute the basis of the 
 alkalies and earths, there ought to be about 870 differ- 
 ent species of binary alloys. But only 132 species have 
 been made and examined. Some metals have so little 
 affinity for others, that as yet no compound of them 
 has been effected, whatever p9ins have been taken. 
 Most of these obstacles to alloying, arise from the differ- 
 ence in fusibility and volatility. Yet a few metals, the 
 melting point of which is nearly the same, refuse to 
 unite. It is obvious that two' bodies will not combine, 
 unless their affinity or reciprocal attraction be stronger 
 tbau the cohesive attraction of their individual particles. 
 To overcome this cohesion of the solid bodies, and ren- 
 der affinity predominant, they must be penetrated by 
 caloric. If one be very difficult of fusion, and the other 
 very volatile, they will not unite unless the reciproca.
 
 20 CHE'MISTRY. 
 
 attraction be exceedingly strong. But if that degree of 
 fusibility be almost the same, they are easily placed in 
 the circumstances most favourable for making an alloy 
 If we are, therefore, far from knowing all the binary 
 alloys which are possible, we are still further removed 
 frot.i knowing all the triple, quadruple, &c. which maj 
 exi .t It must be confessed, moreover, that this depart 
 me it of chemistry has been imperfectly cultivated. 
 
 .Analysis. The resolution, by chemistry, of any matter 
 info its primary and constituent parts. The processes 
 ar d experiments which chemists have recourse to, are 
 Vftiy numerous and diversified, yet they may be reduced 
 tj two species, which comprehend the whole art of 
 f ncmistry. The first is, analysis, or decomposition ; the 
 recond, synthesis, or composition. In analysis, the parts 
 of which bodies are composed, are separated from each 
 otner: thus if we reduce cinnabar, which is composed ot 
 suiphur and mercury, and exhibit those two bodies in a 
 separate state, we say we t have decomposed or analyzed 
 cinnabar. But if, on the contrary, several bodies be 
 mixed together, and a new substance be produced, the 
 J>nx:ess is then termed chemical composition, or synthesis. 
 th<is, if by fusion and sublimation, we combine mercury 
 w.ifi sulphur, and form cinnabar, the operation is termed 
 cl-tmical composition, or composition by synthesis. Chem- 
 ic* i analysis consists of a great variety of operations. 
 L> these operations, the most extensive knowledge of 
 si>ch properties of bodies as are already discovered, must 
 b'- applied, in order to*produce simplicity of effect and 
 c< rtainty in the results. Chemical analysis can hardly 
 b- executed with success, by one who is not in possession 
 ol a considerable number of simple substances, in a state 
 of great purity, many of 'which, from their effects, are 
 called reagents. The word analysis, is often applied by 
 chemists to denote that series of operations by which the 
 component parts of bodies are determined, whether they 
 be merely separated or exhibited apart from each other ; 
 or whether these distinctive properties be exhibited by 
 causing th^m to enter into a new combination, withoul
 
 CHEMICAL TERMS EXPLAINED. "2\ 
 
 the perceptible intervention of a separate state ; and in 
 the chemical examination of bodies, analysis or separa- 
 tion can scarcely ever be effected, without synthesis 
 talcing place at the same time. 
 
 Apparatus. This term is applied to the instruments, 
 .the preparation, and arrangements, of every thing ne- 
 cessary in the performance of any operation, medical, 
 surgical, or chemical. 
 
 Assay. This operation consists in determining the 
 quantity of valuable or precious metal contained in any 
 mineral or metallic mixture, by analyzing a small part 
 thereof. The practical difference between the analysis 
 and assay of an ore, consists in this: The analysis, if 
 properly made, determines the nature and qualities of 
 all the parts of the compound; whereas, the object of 
 the assay consists in ascertaining how much of the par 
 ticular metal in question may be contained in a certain 
 determinate quantity of the material under examination. 
 Thus, in the assay of gold or silver, the baser metal&are 
 considered as of no value or consequence; and the 
 problem to be resolved is simply, how much of each is 
 contained in the ingot or piece of metal intended to be 
 assayed. 
 
 Astringent. That which, when applied to the body, 
 renders the solids denser and firmer, by contracting their 
 fibres, independently of their living, or" muscular power. 
 Astringents thus serve to diminish excessive discharges; 
 and by causing greater compression of the nervous fibril- 
 lae, may lessen morbid sensibility or irritability. Hence 
 they may tend indirectly to restore the strength, when 
 impaired by these causes. The chief class of these 
 articles are the acids, alum, lime-water, chalk, certain 
 preparations of copper, zinc, iron, and lead; the gallic 
 acid, which is commonly found united with the true 
 ivstringent principle, was long mistaken for it. Seguin 
 first distinguished them ; and, from the use of this prin- 
 ciple in tanning skins, has given it the name of tannin 
 Their characteristic dilferences are, the gallic acid forma
 
 22 CHEMISTRY. 
 
 a black precipitate with iron ; the astringent principle 
 forms an insoluble compound with albumen. 
 
 Atmosphere. The elastic invisible fluid which sur 
 rounds the earth to an unknown height, and encloses it 
 on all sides. (See Mr.) 
 
 Moms. In the chemical combination of bodies with 
 each other, it is observed that some unite in all propor 
 tions; others in all proportions as far as a certain point 
 beyond which combination no longer takes place : there 
 are also many examples in which bodies unite in one pro- 
 portion only, and others in several proportions; and these 
 proportions are definite, and in the intermediate ones no 
 combination ensues. And it is remarkable, that when 
 one body enters into combination with another, in several 
 different proportions, the numbers indicating the greater 
 proportions are exact simple multiples of that denoting 
 the smallest proportion. In other words, if the smallest 
 portion in which B. combines with A. be denoted by 10, 
 A. may combine with twice 10 of B. or with three times 
 10, and so on ; but with no intermediate quantities. 
 Fxamples of this kind have of late so much increased in 
 number, that the law of simple multiples bids fair to 
 become universal with respect at least to chemical com- 
 pounds, the proportions of which are definite. By the 
 term atoms, we are to understand the smallest particles 
 of which bodies' are composed. An atom, therefore, 
 must be mechanically indivisible, and of course a fraction 
 of an atom cannot exist, and is a contradiction in terms. 
 Whether the atoms of different bodies be of the same 
 size, or of different sizes, we have no sufficient evidence 
 The probability is, that the atoms of different bodies are 
 of unequal sizes; but it cannot be determined whether 
 their sizes bear any regular proportion to their relative 
 weights. We are equally ignorant of their shape; but 
 it is probable they are spherical. Sir Isaac Newton 
 closes an admirable disquisition on the nature, laws, and 
 constitution of matter, by stating the great probability 
 that God in the beginning formed matter into solid, mas- 
 rive, impenetrable, moveable particles or atoms, of such
 
 CHEMICAL TERMS EXPLAINED. 23 
 
 sizes and figures, and with such other properties, and in 
 such proportion to space, as most conduced to the end 
 for which he formed them ; and that these primitive par- 
 ticles, being absolute solids, are incomparably harder 
 than any of the bodies compounded of them, even so 
 hard as to be incapable of wearing or breaking in pieces, 
 nothing but Infinite Power being able to destroy wl at 
 Infinite Power made one in the first creation. That 
 nature may be lasting, the changes of corporal things are 
 to be attributed only to the various separations and new 
 associations of these permanent particles; and when 
 compound bodies break, it is not in the midst of solid 
 particles, but where these are laid together, and touch 
 only in a few points. 
 
 Attraction. The terms attraction, or affinity, and 
 repulsion, in the language of modern philosophers, are 
 employed merely as the expression of general facts, that 
 the masses or particles of matter have a tendency to 
 approach and unite to, or to recede from one another, 
 under certain circumstances. The term attraction is 
 used synonymously with affinity. 
 
 All bodies have a tendency or power to attract each 
 other, more or less, and it is this power which is called 
 attraction. 
 
 Attraction is mutual : it extends to indefinite distances. 
 All bodies, whatever, as well as their component elemen- 
 tary particles, are endued with it. It is not annihilated, 
 at however great a distance we suppose them to be 
 placed from each other ; neither does it disappear though 
 they be arranged ever so near each other. 
 
 The nature of this reciprocal attraction, or at least 
 tht; cause which produces it, is altogether unknown tc 
 us. Whether it be inherent in all matter, or whether 
 it be the consequence of some other agent, are questions 
 beyond the reach of human understanding ; but its exis- 
 tence is nevertheless certain. 
 
 The instances of attraction which are exhibited by 
 the phenomena around us, are exceedingly numerous, 
 ind continually presenting themselves to our observation.
 
 24 CHEMISTRY 
 
 The effect of gravity, which causes the weight of bodies, 
 is so universal, that we can scarcely form an idea how 
 the universe could exist without it. Other attractions 
 such as those of magnetism and electricity, are likewise 
 observable ; and every experiment in chemistry tends to 
 show, that bodies are composed of various principles or 
 substances, which adhere to each other with vanous 
 degrees of force, and may be separated from each other 
 by known methods. 
 
 The species of attraction called chemical attraction, 
 is also not unfrequeritly designated by the appellation of 
 the attraction of composition, or chemical affinity. This 
 kind of attraction takes place only between the elemen- 
 tary particles of different bodies; and every integrant 
 part of the compound which results from its effects, dif- 
 fers in its properties from any of its component parts 
 It is by this change of properties that chemical combi 
 nation, or the action of chemical attraction, is distinguish- 
 ed from mere mechanical mixture. By mechanical mix- 
 ture, it is obvious, that gold, however minutely divided, 
 could not exist in every part of a fluid lighter than itself; 
 but when the fluid has a chemical attraction for gold, 
 the solution is homogeneous, and incapable of separation 
 by the filter, or any other mechanical means. 
 
 In order to bring affinity fully into action, it is in gen- 
 eral necessary that one or both of the bodies presented 
 to each other, should be in a fluid state ; or that heat 
 should be applied t& disunite the particles, by lessening 
 the attraction of cohesion ; for mechanical subdivision or 
 comminution never extending to the separation of the 
 ultimate particles of bodies, seldom allows that liberty 
 of action, in the exercise of which affinity appears. 
 Instances, however, occur, in which two solids produce a 
 fluid : thus, if pounded ice and muriate of soda be mix- 
 ed together, a fluid brine will be attained, unless the 
 temperature, at the time of the experiment, is lower 
 than that at which brine freezes, and this is thirty-eight 
 degrees below the freezing point of water. 
 
 Dr. Black discovered that whenever a body changes
 
 CHEMICAL TERMS EXPLAINED. 25 
 
 its state by chemical affinity, its temperature is changed 
 at the same time, either lessened or increased. 
 
 The discoveries of Sir H. Davy, seem to establish as 
 a fact, that no chemical affinity takes place between the 
 particles of bodies, unless they be in an opposite electri- 
 cal state ; and that by artificially changing the electrical 
 state of bodies, their affinities may be modified or 
 destroyed. 
 
 The action of the affinity of composition, in differen 
 cases, has been distinguished in the following manner : 
 
 1. When two principles, united together, are sepa- 
 rated by means of a third, we are said to have an ex- 
 ample of simple affinity. This simple affinity, Bergman 
 called simple elective attraction, an expression still much 
 used by chemists. 
 
 2. When a body, composed of two others, cannot be 
 destroyed by a third or fourth body separately applied, 
 yet is destroyed or decompounded by the action of a 
 third and fourth bodies, if these be united before they 
 are added to it ; the example in this case, and when any 
 greater number of bodies are employed, is called com- 
 pound affinity, or compound elective attraction. 
 
 3. \\ hen two bodies which have no perceptible action 
 on each other, unite by the addition of a third body, the 
 example is called intermediate affinity. It is instanced 
 in the union of oil and water, by the means of an alkali. 
 
 Tables of elective attraction have been constructed, 
 which are of singular service in directing the attention 
 of the chemist to the effects of substances on each other: 
 we shall advert to them when we have considered the 
 properties of substances themselves. 
 
 Bases. This term is usually applied to alkalies, earths, 
 and metallic oxides, in their relations to the acids and 
 salts. It is someumes also applied to the particular con- 
 stituents of an acid or oxide, on the supposition that the 
 substance combined with the oxygen, &c. is the basis of 
 the compound to which it owes its particular qualities, 
 This notion seems unnhilosophical, as these qualities de- 
 3
 
 26 CHEMISTRY. 
 
 pend as much on the state of combination as on the na 
 lure of the constituent. 
 
 Bi. This term is used in anatomy, botany, and chem 
 istry : in composition* it signifies twice or double. 
 
 Calcareous. Substances which partake somewhat of 
 the nature and qualities of calx. 
 
 Calcination. The fixed residues of such matters as 
 have undergone 9ornbustion are called cinders, in com- 
 mon language, and calxes, but now more commonly ox- 
 ides, by chemists ; and the operation, when considered 
 with regard to these residues, is termed calcination. In 
 this general way, it has likewise been applied to bodies 
 not really combustible, but only deprived of some of 
 their principles by heat. Thus we hear of the calcina- 
 tion of chalk, to convert it into lime by driving off the 
 carbonic acid and water; of gypsum, or piaster-stone, 
 of alum, of borax, and other saline bodies, by which 
 they are deprived of their water of crystallization ; of 
 bones, which lose their volatile parts by this treatment, 
 and of various other bodies. It is also applied to metals, 
 in their combination with oxygen, by means of heat. 
 
 Caloric. That which produces the sensation of heat 
 (See Caloric.) 
 
 Carburet. A combination of charcoal with any other 
 substance: thus carburetted hydrogen is hydrogen hold- 
 ing carbon in solution; carburetted iron isjsteel, &c. 
 
 Caustic. (To burn ; because it always causes a burn- 
 ing sensation.) A substance which always causes a burn- 
 ing sensation, and has so strong a tendency to combine 
 with organized substances, as to destroy their texture. 
 
 Caivk. A term by which the miners distinguish the 
 opaque specimens of sulphate of barytes. 
 
 Cementation. A process in which a body in a solid 
 state, is surrounded by another in powder, and exposed 
 for some time in a close vessel to a degree of heat which 
 will not fuse either of the bodies. Iron thus surrounded 
 by charcoal is converted into steel ; a.?d copper, by ce- 
 aientation with calamine and charcoal, is converted into
 
 CHEMICAL TERMS EXPLAINED. 27 
 
 brass : green bottle-glass is coLverted into porce.am by 
 cementation with sand, tfcc. 
 
 Chlorute. A compound of chloric acid with a salifiable 
 basis. 
 
 Coagulation. The separation of the coagulable par- 
 ticles, contained in any fluid, from the more thin and not 
 coagulable particles: thus, when milk curdles, the co- 
 agulable particles form the curd; and when acids art 
 thrown into any fluid containing coagulable particles, 
 they form what is called coagulurn.. 
 
 Combination. The intimate union of the particles of 
 different substances by chemical attraction, so as to form 
 a compound possessed of new and peculiar properties. 
 
 Combustion. The union of a body with oxygen ac- 
 companied by the evolution of light and heat; therefore 
 every body which is capable of forming this union, is 
 called a combustible. (See Combustion.) 
 
 Compound. The result or effect of a composition of 
 different things; or that which arises from them. It 
 stands opposed to simple. 
 
 Concentration. A process by which the watery part 
 of any fluid is separated, by evaporation ; or the volatil- 
 izing of part of the water of fluids, in order to improve 
 their strength. The matter, therefore, to be concen- 
 trated, must be of superior fixity to water. This opera- 
 tion is performed on some acids, particularly the sulphu- 
 ric and phosphoric. It is also employed in solutions of 
 alkalies and neutral salts 
 
 Concretion. The condensation of any fluid substance 
 into a more solid consistence. 
 
 The growing together of parts which, in a natural 
 state, are separate. 
 
 Condensation. The thickening of any fluid. 
 
 Congelation. The change of liquid bodies, which 
 takes place when they pass to a solid state, by losing 
 the caloric which kept them in a fluid state. 
 
 Crystallization. A property by which crystallizable 
 bodies tend to assume a regular form, when placed favour- 
 able to that particular disposition of their particles. Al
 
 28 CHEMISTRY. 
 
 most all minerals possess this property, but it is most 
 eminent in saline substances. The circumstances which 
 are favourable to crystallisation of salts, and without 
 which it cannot take place, are two: 1. Their particles 
 must be divided and separated by a fluid, in order that 
 the corresponding faces of those particles may meet and 
 unite. 2. In order that this union may take place, the 
 fluid which separates the integrant parts of the salt must 
 be gradually carried ofF, so that it may no longer divide 
 them. (See Crystallization.) 
 
 Cupellation. The purifying of perfect metals by 
 means of an addition of lead, which, at a due heat 
 becomes vitrified, and promotes the vitrification and cal- 
 cination of such imperfect metals as may be in the mix- 
 ture, so that these last are carried off in the fusible 
 glass that is formed, and the perfect metals are left 
 nearly pure. The name of this operation is taken from 
 the vessels made use of, which are called cupels. 
 
 Decantation. The separation of a fluid from the un- 
 dissolved particles or solids which it contains. This is 
 done by leaving the fluid at rest in a conical vessel ; and 
 when the foreign matter has deposited itself at the bot- 
 tom, the fluid is gently poured off, in order not to disturb 
 the sediment. When the matter deposited is light, and 
 apt to mix with the fluid, or when the vessel containing 
 it cannot be conveniently moved, a siphon is employed to 
 draw it off A thick woollen thread steeped in the 
 liquor, and inclining over the edge of the vessel, makes 
 a very good siphon for this purpose. 
 
 Decoction. A fluid holding in solution some substance 
 which it has obtained by boiling : thus we say a decoc- 
 tion of bark, &c. When the preparation is made by 
 cold water, it is called an infusion. 
 
 Decomposition. The substances of which any com- 
 pound body is formed, are called its component or con- 
 stituent parts ; and when these are separated from each 
 other, the body is said to be decomposed, or to have 
 undergone decomposition. Thus soap is compounded ol 
 w\ and an alkali ; and when the 'oil and alkali are sepa 
 F^ted from each r'.} r, the soap is decomposed.
 
 CHEMICAL TERMS tXPL^INED. 29 
 
 Decrepitation. The small and successive explosions 
 which take place in many chemical operations, as when 
 salts are exposed to heat. 
 
 Deflagration. A chemical term, chiefly employed to 
 express the burning or setting fire to any substance ; as 
 nitre, sulphur, &c. 
 
 Deplegmation. The operation of rectifying or freeing 
 spirits from their watery parts, or any method by which 
 bodies are deprived of their water. 
 
 Dephlogisticated. A term of the old chemistry, im 
 plying, deprived of phlogiston, or the inflammable prin- 
 ciple. 
 
 Deliquescence. The state of a salt which becomes 
 fluid by its absorption of moisture from the atmosphere. 
 
 Desiccation. (Drying.) The expelling or evaporating 
 of humid matter from any substance, by means of heat. 
 
 Descensus. Chemists call this a distillation by descent, 
 when the fire is at the top and round the vessel, the ori- 
 fice of which is at the bottom. 
 
 Detonation. An explosion caused by a sudden expan- 
 sion and combustion of certain substances ; it differs from 
 decrepitation in being more rapid,- and louder. 
 
 Digestion. The slow action of a solvent upon any sub- 
 stance, whether assisted by heat or not. 
 
 Distillation. The separation by heat of a volatile fluid 
 from other substances which are fixed ; or the separation 
 of substances more or less volatile from each other. (See 
 Distillation.) 
 
 Ductility. A property by which bodies are elongated 
 by repeated or continued pressure. It is peculiar to 
 metals. Most authors confound the words malleability, 
 laminability, and ductility, together, and use them in a 
 loose indiscriminate way ; but thev are very different. 
 Malleability is the property of a body which enlarges 
 one or two of its three dimensions by a blow or pressure 
 very suddenly applied. Laminability belongs to bodies 
 extensible in dimension by a gradually applied pressure; 
 and ductility is properly to be attributed to such bodies 
 as can be rendered longer and thinner by drawing them 
 3*
 
 30 CHBMISTRT. . 
 
 through a hole of less area than the transverse section 
 of the body so drawn. 
 
 Ebullition. This consists in the change which a fluid 
 undergoes from a state of liquidity to that of an elastic 
 fluid, in consequence of the application of heat, which 
 dilates and converts it into vapour. 
 
 Effervescence. The bubbling and noise produced by 
 the escape of volatile parts from a fluid, or the agitation 
 which is produced by mixing substances together, which 
 cause the evolution of a gas. 
 
 Efflorescence. That which takes place when bodies 
 spontaneously become converted into a dry powder. It 
 is almost always occasioned by the loss of the water of 
 crystallization in saline bodies. 
 
 Elastic. Having the power of returning to the form 
 from which it has been forced to deviate, or from which 
 it is withheld ; thus a blade of steel is said to be elastic, 
 because if it is bent to a certain degree, and then let go, 
 it will of itself return to its former situation; the same 
 will happen to the branch of a tree, a piece of Indian 
 rubber, &c. 
 
 Elif/u.ation. An operation in which a substance is 
 separated from another which is less fusible, by the 
 application of a degree of heat which will fuse only the 
 former; thus copper may be separated from its alloy 
 with lead, with a degree of heat which is sufficient only 
 to melt the lead. 
 
 Equivalents. A term introduced into chemistry by 
 Dr. Wollaston, to express the system of definite ratios, in 
 which the corpuscular objects of this science reciprocally 
 unite! 
 
 Essence. Several of the volatile or essential oils are 
 called by this name. 
 
 Etheieal. A term applied to any highly rectified 01 
 essential oil, or spirit. 
 
 Evaporation. A chemical process usually performed 
 by applying heat to any compound substance, in ordei 
 to dispel the volatile parts. It differs from distillation in 
 its object, which chiefly consists in preserving the more
 
 CHEMICAL TERMS EXPLAINED. 31 
 
 fixed matters, while the volatile substances are dissipated 
 and lost. And the vessels are accordingly different 
 evaporation being made in open shallow vessels, and 
 distillation in an apparatus nearly closed from the exter- 
 nal air. 
 
 The degree of heat must be duly regulated in evapo- 
 ration When the fixed and more volatile parts do no 
 lifter greatly in their tendency to fly off, the heat mus 
 be very carefully adjusted ; but in other cases this is less 
 oecessary. As evaporation consists in the assumption of 
 the elastic form, its rapidity will be in proportion to the 
 degree of heat, and the diminution of the pressure of 
 the atmosphere. 
 
 Extract. The solid matter obtained by evaporating 
 ihc watery parts of a decoction or infusion. 
 
 Fermentation. A slow motion of the intestine par- 
 tirles of a mixed body. 
 
 Filtration. An operation by which a fluid is mechan- 
 ically separated from consistent particles mixed with it. 
 IT does not differ from straining. 
 
 An apparatus fitted for this purpose is called a filter. 
 The form of this is various, according to the intention of 
 the operator. A piece of tow, or wool, or cotton, stuffed 
 into the pipe of a funnel, will prevent the passage of 
 grosser particles, and by that means render the fluid 
 clearer which comes through. Sponge is still more 
 effectual. A strip of linen rag wetted and hung over 
 the side of the vessel containing the fluid, in such a 
 manner that one end of the rag may be immersed in the 
 fluid, and the other end may remain without, below the 
 surface, will act as a siphon, and carry over the clearer 
 portion. Linen or woollen stuffs may either be fastened 
 over the mouths of proper vessels, or fixed to a frame 
 like a sieve, for the purpose of filtering. All these are 
 more commonly used by cooks and apothecaries than by 
 philosophical chemists, who, for the most part, use the 
 paper called cap paper, made up without size. 
 
 As the filtration of considerable quantities of fluid 
 could not be effected at once without breaking the pa-
 
 32 CHEMISTRY. 
 
 per, it is found requisite to use a linen cloth, upon which 
 the paper is applied and supported. 
 
 Precipitates and other pulverulent matters are col- 
 lected more speedily by filtration than by subsidence. 
 But there are many chemists who disclaim the use of 
 this method, and avail themselves of the latter only,' 
 which is certainly more accurate, and liable to no objec- 
 tion, where the powders are such as will admit of eclul- 
 coration and drying in the open air. 
 
 Some fluids, as turbid water, may be purified by filter- 
 ing through sand. A large earthen funnel, or stone bot- 
 tle with the bottom beaten out, may have its neck loosely 
 stopped with small stones, over which smaller may be 
 placed, supporting layers of gravel increasing in fine- 
 ness, and lastly covered with a few inches of fine sand, 
 all thoroughly cleaned by washing. This apparatus is 
 superior to a filtering-stone, as it will clean water in 
 large quantities, and may be readily renewed when the 
 passage is obstructed, by taking out and washing the 
 upper stratum of sand. 
 
 A filter for corrosive liquors may be constructed, on 
 the same principles, of broken and pounded glass, (lire's 
 Chem. Diet.) 
 
 Fixed. An epithet descriptive of such bodies as so far 
 resist the action of heat as not to rise in vapour. It is 
 the opposite of volatile; but it must be observed, that 
 the fixity of bodies is merely a relative term, as an ade- 
 quate degree of heat will dissipate all. 
 
 Fluate. A compound of the fluoric acid with salifiable 
 bases : thus, fluate of lime, &c. 
 
 Fluid. A fluid is that, the particles of which so little 
 attract each other, that when poured out, it drops, and 
 adapts itself in every respect to the form of the vessel 
 containing it. (See Fluid.) 
 
 Flux. A general term made use of to denote any sub- 
 stance or mixture added to assist the fusion of metals. 
 
 Fluxion. A term mostly applied to signify the change 
 of metals, or other bodies, from the solid into a fluid 
 state, by the application of heat. (See Fusion.)
 
 CHEMICAL TERMS EXPLAINED. 33 
 
 Fulmination. A still more violent and sudden explo- 
 sion than detonation. 
 
 Fusion. A chemical process, by which bodies are 
 made to pass from a solid to a fluid state by means of 
 the application of heat. The chief objects susceptible 
 of this operation are salts, sulphur, and metals. Salts 
 are liable to two kinds of fusion : the one, which is pe- 
 culiar to saline matters, is owing to water contained in 
 them, and is called aqueous fusion ; the other, which 
 arises from the heat alone, is known by the name of 
 igneous fusion. 
 
 Gas. Elastic fluid ; aeriform fluid. This term is ap- 
 plied to all permanently elastic fluids, simple or com- 
 pound, except the atmosphere, to which the term air is 
 appropriated. (See. Gas.) 
 
 Ide. This terminal is affixed to oxygen, chlorine, and 
 /odine, when they enter into combination with each 
 other, or with simple combustibles or metals, in propor- 
 tions not forming an acid ; thus ox-ide of chlorine, ox-ide 
 of nitrogen, chlor-ide of sulphur, iod-ide of iron. 
 
 Incineration. The burning of vegetable or animal 
 substances, to obtain their ashes, or fixed residue, which 
 is lixiviated. 
 
 Inflammable. Chemists distinguish by this term such 
 substances as burn with facility, and flame in an increased 
 temperature. 
 
 Infusion. A process that consists in pouring water 
 of any required degree of temperature on such sub- 
 stances as have a loose texture ; as thin bark, wood in 
 shavings or small pieces, leaves, flowers, &c., and suffer- 
 ing it to stand a certain time. The liquor obtained by 
 the above process is called an infusion. 
 
 lodate. A compound of iodine with oxygen, and a 
 metallic basis. 
 
 Iodide. A compound of iodine with a metal ; as Iodide 
 sf pot-assium. 
 
 Lacquer. A solution of lac in alcohol. 
 
 Lactate. A definite compound formed by the union 
 of the acid of whey, or lactic acid, with salifiable bases ; 
 thus, luctate of potassa, &c. 
 
 C
 
 34 CHEMISTRY. 
 
 Letigation. The reduction of a hard substance, by 
 triture, to an impalpable powder. 
 
 Liquefaction. A term sometimes used synonymously 
 with fusion, in others with the word deliquescence, an^ 
 in others with the word solution. 
 
 Lixiviation. The application of water to the fixe- 1 
 residues of bodies, for the purpose of extracting th>- 
 saline parts, which dissolve in the water, and afterward" 
 crystallize on evaporation. 
 
 Maceration. This term implies an infusion either wid- 
 er without heat, wherein the ingredients are intended ti 
 be almost wholly dissolved in order to extract theii 
 virtues. 
 
 Magistery. An obsolete term used by ancient chem- 
 ists to signify a peculiar and secret method of preparing 
 any medicine, as it were by a masterly process. The 
 term was also long applied to all precipitates. 
 
 Martial. Sometimes used to express preparations of 
 iron, or such as are impregnated therewith ; as the mar- 
 tial regulus of antimony, &c. 
 
 Menstruum. All liquors are so called which are used 
 as dissolvents, or to extract the virtues of ingredients by 
 infusion, decoction, &c. 
 
 Mineralize. Metallic substances are said to be min- 
 eralized when deprived of their usual properties by com- 
 bination with some other substance. 
 
 Mother-water. When sea-water, or any other selec- 
 tion containing various salts, is evaporated, and the crys- 
 tals taken out, there always remains a fluid containing 
 deliquescent salts, and the impurities, if present. This 
 is called the mother-water. 
 
 Neutral. A term applied to saline compounds of an 
 acid and an alkali, which are so called, because they do 
 not possess the characters of acid or alkaline salts; such 
 are Epsom-salts, nitre, and all the compounds of alkalies 
 with acids. 
 
 Neutralization. When acid and alkaline matter are 
 combined in such proportions, that the compound does 
 not change the colour of litmus or violets, they are said 
 to be neutralized.
 
 CHEMICAL TERMS EXPLAINED. 35 
 
 Oxidation. The process of converting metals and 
 other substances into oxides, by combining with them a 
 certain portion of oxygen. It differs from acidification 
 in the addition of oxygen not being sufficient to form an 
 acid with the substance oxidized. 
 
 Oxide. A substance combined with oxygen without 
 being in the state of an acid. Many substances are sus- 
 ceptible of several stages of oxidizement, on which ac 
 count chemists have employed various terms to express 
 the characteristic distinctions of the several oxides. The 
 specific name is often derived from some external char- 
 acter, chiefly the colour; thus we have the black and 
 red oxides of iron, and of mercury ; the white oxide of 
 zinc : but in most instances the denominations proposed 
 by Dr. Thompson are adopted. When there are several 
 oxides of the same substance, he proposes the terms 
 protoxide, deutoxide, tritoxide, signifying the first, second, 
 and third stage of oxidizement. Or if two oxides only 
 are known, he proposes the appellation of protoxide foi 
 that at the minimum, and of peroxide for that at the 
 maximum, of oxidation. The compounds of oxides and 
 water in which the water exists in a condensed state : 
 are termed hydrates, or hvdroxures. 
 
 Oxygenation. This word is often used instead of oxida- 
 tion, and frequently confounded with it ; but it differs in 
 being of more general import, as every union with oxy- 
 gen, whatever the product may be, is an oxygenation : 
 but oxidation takes place only when an oxide is formed. 
 
 Oxyiode. A term applied by Sir H. Davy to the triple 
 compounds of oxygen, iodine, and the metallic bases. 
 Lussac calls them iodates. 
 
 Petrifactions. Stony matters deposited either in the 
 way of incrustation, or within the cavities of organized 
 substances, are called petrifactions. Calcareous earth 
 being universally diffused, and capable of solution in 
 water, either alone or by the medium of carbonic acid 
 or sulphuric acid, which are likewise very abundant, is 
 deposited whenever the water or the acid becomes dissi- 
 oated. In this way we have incrustations of limestone
 
 3G CHEMISTRY. 
 
 or of selenite in the form of stalactites or dropstones 
 from the roofs of caverns, and in various other situations* 
 The most remarkable observations relative to petri 
 factions are thus given by Kerwan : 
 
 1. That those of shells are found on, or near, the sur- 
 face of the earth ; those of fish, deeper ; those of wood, 
 deepest. Shells in specie are found in immense quanti- 
 ties at considerable depths. 
 
 2. That those organic substances that resist putrefac- 
 tion most, are frequently found petrified ; such as shells, 
 and the harder species of woods : on the contrary, those 
 that are aptest to putrefy are rarely found petrified; 
 as softer parts of animals, fish. &c. 
 
 3. That they are most found in strata of marl, chalk, 
 limestone, or clay, seldom in sandstone, still more rarely 
 in gypsum ; but never in gneiss, granite, basalts, or 
 shale ; but they sometimes occur in pyrites, and ores of 
 iron, copper, and silver, and almost always consist of that 
 species of earth, stone, or other mineral that surrounds 
 them, sometimes of silex, agate, or cornelian. 
 
 4. That they are found in climates where their ori- 
 ginals could not have existed. 
 
 5. That those found in slate or clay are compressed 
 and flattened 
 
 Phlegm. In chemistry this term means the water from 
 distillation. 
 
 Phlogiston. The supposed general inflammable prin- 
 ciple of Stahl, who imagined it was pure fire, or the 
 matter of fire fixed in combustible bodies, in order to dis- 
 tinguish it from fire in action, or in a state of liberty. 
 
 Phosphate. A salt formed by the union of phosphoric 
 acid with salifiable bases; thus, phosphate of ammonia, 
 phosphate of lime, &c. 
 
 Precipitation. When two bodies are united, for in 
 stance, an acid and an oxide, and a third body is added, 
 such as an alkali, which has a gret ter affinity with the 
 acid than the metallic oxide has, the consequence is, 
 that the alkali combines with the acid, and the oxide 
 thus deserted appears in a separate state, at the bottom
 
 CHEMICAL TEIOIu EXPLAINED. 37 
 
 Dl *'i vessel in which the operation is performed. This 
 de .an j position is commonly known by the name of pre.- 
 cip-tiattun, and the substance that sinks is named a pre- 
 cip.catt. The substance, by the addition of which the 
 phenomenon is produced, is denominated the precipitant. 
 
 1 rinciples. Substances o r particles, which are com- 
 posed of two or more e! Clients; thus water, gelatine. 
 siiL'Kr, fibrine, &c., are the principles of many bodies. 
 These principles are composed of elementary bodies, as 
 oxygen, hydrogen, azote, &c., which are uridecomposable. 
 
 Putrefaction. (To become rotten, to dissolve.) Pu- 
 trid fermentation. The spontaneous decomposition of 
 animal and vegetable matters, that exhale a foetid smell. 
 The solid and the fluid matters are resolved into gaseous 
 compounds and vapours, which escape and unite an 
 earthy residuum. The requisites to this process are: 
 1. A certain degree of humidity. 2. The access of 
 atmospheric air. 3. A certain degree of heat. Hence 
 the abstraction of the air and water, or humidity, b) 
 drying, or us fixation by cold, by salt, sugar, spices, &c., 
 will counteract the process of putrefaction, and favoui 
 the preservation of food, on which principle some patent* 
 have been obtained. 
 
 Pyrites. (So called because it strikes fire with steel.) 
 Native compounds of metal with sulphur. 
 
 Radical. This term is applied to that which is con 
 sidered as constituting the distinguishing part of an acid 
 by its union with the acidifying principle or oxygen, 
 which is common to all acids. Thus sulphur is the rad- 
 ical of sulphuric and sulphurous acids. It is sometimes 
 called the base of the acid ; but base is a term of more 
 extensive application. 
 
 Rancidity. The change which oils undergo by ex- 
 posure to air, which is probably an effect analogous to 
 the oxidation of metals. 
 
 Reagent Test. A substance used in chemistry to 
 detect the presence of other bodies. In the application 
 of tests, there are two circumstances to attend to: viz 
 co avoid deceitful appearances, and to have good tests
 
 38 CHEMISTRY. 
 
 The principal tests are the following: 
 
 1. Litmus. The purple of litmus is tuined to red by 
 every acid ; so that this is the test generally made use 
 of to detect the excess of acid in every fluid. It may be 
 used either by dipping into the water a piece of paper 
 stained with litmus, or by adding a drop of the tincture 
 to the water to be examined, and comparing its hue with 
 that of an equal quantity of the tincture in distilled 
 water. 
 
 Litmus already reddened by an acid, will have its pur- 
 ple restored by an alkali ; and thus it may also be used 
 as a test for alkalies, but it is much less active than 
 other direct alkaline tests. 
 
 2. Red cabbage has been found by Watt to furnish as 
 delicate a test for acids as litmus, and to be still more 
 sensible for alkalies. The natural colour of an infusion 
 of this plant is blue, which is changed to a red by acids, 
 and to a green by alkalies in very minute quantities. 
 
 3. Brazil wood. When chips of this wood are infused 
 in warm water, they yield a red liquor, which readily 
 turns blue by alkalies, either caustic or carbonated. lit 
 is also rendered blue by the carbonated earths held in 
 solution by carbonic acid, so that it is not an unequivocal 
 test of alkalies till the earthy carbonates have been pre- 
 cipitated by boiling. Acids change to yellow the natural 
 red of Brazil wood, and restore the red when changed 
 by alkalies. 
 
 4. Violets. The delicate blue of the common scented 
 violet is readily changed to green by alkalies, and this 
 rtffords a delicate test for these substances. Syrup of 
 violets is generally used as it is at hand, being used in 
 medicine. But a tincture of this flower will .answer as 
 well. 
 
 5. Turmeric. This is a very delicate test for alkalies 
 and on the whole, perhaps, is the best. The natural 
 colour, either in watery or spirituous infusion, is yellow, 
 which is changed to a brick or orange red by alkalies, 
 saustic or carbonated, but not by carbonated earths, on 
 which account it is preferable to Brazil wood. The pure
 
 
 CHEMICAL TERMS EXPLAINED. 39 
 
 earths, such as lime and barytes, produce the same 
 change. 
 
 0. Rhubarb. Infusion or tincture of. rhubarb under- 
 goes a similar change with turmeric, and is equally deli- 
 cate. 
 
 7. Sulphuric acid. A drop or two of concentrated 
 sulphuric acid, added to water that contains carbonic 
 acid, free or in combination, causes the latter to escape 
 with a pretty brisk effervescence, whereby the presence 
 of this gaseous acid may be detected. 
 
 8. J\1tric and oxymuriatic add. A peculiar use 
 attends the use of these acids in the sulphuretted waters, 
 as the sulphuretted hydrogen is decomposed by them, its 
 hydrogen absorbed, and the sulphur separated in its natu- 
 ral form. 
 
 Oxalic acid and oxalate of ammonia. These are 
 the most delicate tests for lime and all soluble calcareous 
 salts. Oxalate of lime, though nearly insoluble in water, 
 dissolves in a moderate quantity in its own or any other 
 acid, and hence in analysis oxalate of ammonia is often 
 preferred, as no access of this salt can redissolve the pre- 
 cipitated oxalate of lime. On the other hand, the am- 
 monia should not exceed, otherwise it might give a false 
 indication. 
 
 10. Gallic acid and tincture of galls. These are 
 tests of iron. Where the iron is in very minute quan- 
 tities, and the water somewhat acidulous, these tests do 
 not always produce a precipitate, but only a slight red- 
 dening, but their action is much heightened by previously 
 adding a few drops of any alkaline solution. 
 
 11. Prussiate of potassa or lime. The presence of 
 iron in water is indicated by thes^ prussiates causing a 
 blue precipitate: and if the prussiate of potassa is prop- 
 erly prepared, it will only be precipitated by a metallic 
 salt, so that manganese and copper will also be detected, 
 the former giving a white precipitate, the latter a red 
 precipitate. 
 
 12. Lime-water, is the common test for carbonic acid; 
 it decomposes all the magnesian salts, and likewise the
 
 40 CHEMISTRr. 
 
 aluminous salts ; it likewise produces a cloudiness with 
 most of the sulphates, owing to the formation of selenite 
 
 13. Ammonia. This alkali when perfectly caustic, 
 serves as a distinction between the salts of lime and those, 
 of magnesia, as it precipitates the earth from the latter 
 salts, but not from the former. There are two sources 
 of error to be obviated, one is that of carbonic acid 
 being present in the water, the other is the presence of 
 aluminous salts. 
 
 14. Carbonated alkalies. These are used to pcecipi 
 tate all the earths ; where carbonate of potassa is used, 
 particular care should be taken of its purity, as it gen- 
 erally contains silex.* 
 
 15. Muriated alumine. This test is proposed by Mr. 
 Kirwan, to detect carbonate of magnesia, which cannot, 
 like carbonated lime, be separated by ebullition, but 
 remains till the whole liquid is evaporated. 
 
 16. Barytic salts. The nitrate, muriate, and acetate 
 of barytes are all equally good tests of sulphuric acid in 
 any combination. 
 
 17. Salts of silver. The salts of silver are the most 
 delicate tests of muriatic acid, in any combination, pro- 
 ducing the precipitated luna cornea. "All the salts of 
 silver likewise give a dark brown precipitate with sul- 
 phurated waters, which is as delicate a test as any we 
 
 18. Salts of lead. The nitrate and acetate of lead 
 are the salts of this metal employed as tests. They will 
 indicate the sulphuric, muriatic, and boracic acids, and 
 sulphuretted hydrogen or sulphuret of potassa. 
 
 19. Soap. A solution of soap in distilled water, or in 
 alcohol, is curdled by water containing any earthy or 
 metallic salt. 
 
 20. Tartaric acid. This acid is of use in distinguish- 
 ing the salts of potassa (with which it forms a precipitate 
 of cream of tartar,) from those of soda, from which it 
 does not precipitate. The potassa, however, must earnt 
 in some quantity to be detected by the test. 
 
 21. Nitromuriate of platium. This sort is still mo"
 
 CHEMICAL TERMS EXPLAINED. 41 
 
 discriminative between potassa and the other alkalies 
 than acid of tartar, and will produce a precipitate with 
 a very weak solution of any salt with potassa. 
 
 22. Alcohol. This most useful reagent is applicable 
 in a variety of ways in analysis. As it dissolves some 
 substances found in fluids, and leaves others untouched, 
 it is a means of separating them into two classes, which 
 saves considerable trouble in the further investigation. 
 Those salts which it does not dissolve, it precipitates 
 from their watery solution, but more or less completely 
 according to the alt contained, and the strength of the 
 alcohol; and as a precipitant it also assists in many 
 decompositions. 
 
 Rectification. (To make clean.) A second distilla- 
 tion, in which substances are purified by their more 
 volatile parts being raised by heat carefully managed : 
 thus, spirits of wine, ether, &c., are rectified by their 
 separation from the less volatile and foreign matter 
 which altered or debased their properties. 
 
 Reduction. When a metal is converted into an oxide 
 by its combining with oxygen, it loses its metallic prop- 
 erties, and assumes the appearance of an earth ; but 
 when the oxygen with which it is combined is taken from 
 it, all its properties as a metal are recovered ; in this 
 case the metal is said to be reduced, and the operation 
 by which it is effected is called reduction. Revivifica- 
 tion is a word used in the same sense as reduction, but 
 is most commonly employed where mercury is the metal 
 used. 
 
 Residuum, is that part of a body which remains aftei 
 the most valuable parts have been separated by com- 
 bustion, distillation, or sublimation. 
 
 Roasting, a preliminary operation, which prepares 
 mineral substances for undergoing a series of succeeding 
 ones, dividing their constituent particles, volatilizing some 
 of their principles, and thus, in a certain degree, altering 
 their nature. Ores are exposed to this process, with a 
 view to separate the sulphur and the arsenic which 
 they contain, and to diminish the cohesion of their par 
 4*
 
 42 CHEMISTRY. 
 
 tides. Capsules of earth or iron, crucibles, and roasting 
 pots, are the vessels in which it is usually performed ; 
 and the ore is generally exposed to the access of exter- 
 nal air. Sometimes, however, the operation is performed 
 in close vessels; and two crucibles, luted mouth to 
 mouth, may be employed on such occasions. Roasting 
 is synonymous with toref action and ustulation. 
 
 Sal. (See Saline.) 
 
 Salifiable. Having the property of forming a salt 
 The alkalies, and those earths and metallic oxides which 
 have the power of neutralizing acidity, entirely or in 
 part, and producing salts, are called salifiable bases. 
 
 Saline. (From sal, salt.) Of a salt nature. The 
 number of saline substances is very considerable; and 
 they possess peculiar characters by which they are dis- 
 tinguished from other substances. These characters are 
 founded on certain properties, which, it must be con- 
 fessed, are not accurately distinctive of their true nature. 
 All such substances, however, as possess several of the 
 four following properties, are considered as saline: 
 1. A strong tendency to combination, or a very strong 
 affinity of composition. 2. A greater or lesser degree 
 of sapidity. 3. A greater or lesser degree of solubility 
 in water. 4. Perfect incombustibility. 
 
 Saturation. Most bodies which have a chemical 
 affinity for each other, will only unite in certain propor- 
 tions. When, therefore, a fluid has dissolved as much 
 of any substance as it is capable of dissolving, it is said 
 to have reached the point of. saturation. Thus water 
 will dissolve one quarter of its weight of common salt, 
 and if .more salt be added, it will sink to the bottom in*a 
 solid state. Some fluids will dissolve more of certain 
 substances when hot than when cold. Thus water, 
 when hot, will dissolve a much larger quantity of nitre 
 than when cold. 
 
 Sediment. The heavy parts of liquids which fall to 
 the bottom. 
 
 Semi. In composition, this term universally means half. 
 
 Simple. This term is applied very generally in every
 
 CHEMICAL TERMS EXPLAINED. 43 
 
 department of nature, to designate that which is not 
 compound. 
 
 Solution. The dispersion of the particles of a solid 
 oody in any fluid, in so equal a manner that the compound 
 liquor shall be perfectly and permanently clear and 
 transparent. This takes place when the particles of the 
 fluid have an affinity or elective attraction for the parti- 
 cles of the solid. When solid particles are only dispersed 
 in a fluid by mechanical means, it is mixture, not solu- 
 tion, and the compound usually opaque and muddy. 
 
 Specific gravity. The density of the matter of which 
 anv body is composed, compared to the density of an- 
 other body, assumed as the standard. This standard is 
 pure distilled water, at the temperature of 60 F. To 
 determine the specific gravity of a solid, we weigh it, 
 first in air, and then in water. In the latter case, it 
 loses of its weight a quantity precisely equal to the 
 weight of its own bulk of water ; and hence, by com- 
 paring this weight with its total weight, we find its spe- 
 cific gravity. The rule therefore is, divide the total 
 weight by the loss of weight in water, the quotient is 
 the specific gravity. If it be a liquid or gas, we weigh 
 it in a glass or other vessel of known capacity ; and di- 
 viding the weight by the same bulk of water, the quo- 
 tient is, as before, the specific gravity. 
 
 Spirit. This name was formerly given to all volatile 
 substances collected by distillation. Three principal 
 kinds were distinguished : inflammable or ardent spirits, 
 acid spirits, and alkaline spirits. The word spirit is now 
 almost exclusively confined to alcohol. 
 
 Stratification. An operation in which bodies are placed 
 alternately in -ayers, in order that they may act upon 
 each other w) en heat is applied to them. It is nearly 
 the same wiO- cementation, but cementation is more par- 
 ticularly app : ied to the cases already noted. 
 
 Sub. This term is applied when a salifiable base is 
 predominant in a compound, there being a deficiency of 
 Ihe acid ; a. subcarbonate of potassa, subcarbonate oj 
 tofla.
 
 44 CHEMISTRY. 
 
 Sublimation. A process by which volatile substances 
 are raised by heat, and again condensed in a solid form. 
 This process differs from evaporation only in being con 
 fined to solid substances. It is usually performed either 
 for the purpose of purifying certain substances, and dis- 
 engaging them from extraneous matters ; or else to re- 
 duce into vapour, and combine, under that form, princi- 
 ples which would have united with greater difficulty if 
 they had not been brought to that state of extreme 
 division. 
 
 As all fluids are volatile by heat, and consequently 
 capable of separation, in most cases, from fixed matters, 
 so various solid bodies are subjected to similar treatment 
 Fluids are said to distil, solids to sublime ; though some- 
 times both are obtained in one and the same operation. 
 If the subliming matter converts into a solid hard mass, 
 it is commonly called a sublimate; if into a powdery 
 form, flowers. 
 
 The principal subjects of this operation are, volatile 
 alkaline salts; neutral salts, composed of volatile alkali 
 and acids, as sal ammonia ; the salt of amber, and flow- 
 ers of benzoin, mercurial preparations, and sulphur 
 Bodies of themsSlves not volatile are frequently made to 
 sublime by the mixture of volatile ones ; thus iron is car- 
 ried over by sal ammoniac in the preparation of the 
 flores martiales, or ferrum ammoniatum. 
 
 The fumes of solid bodies in close vessels rise but a 
 little way, and adhere to that part of the vessel where 
 they concrete. 
 
 Super. This term is applied to several saline sub- 
 stances, in which there is an excess of one of its con. 
 stituents beyond what is necessary to form the ordinary 
 compound ; as supersulphate of potassa, supercarbonate 
 of soda, &c. 
 
 Trituration. The act of reducing a solid body into a 
 subtile powder ; as woods, barks, &c. It is performed 
 mostly by the rotary motion of a pestle in metallic 
 glass, or wedgewood mortars. 
 
 UreL The compounds of simple inflammable bodies
 
 CHEMICAL APPARATUS DESCRIBED. 4.1 
 
 with each other, and with metals, are commonly desig- 
 nated by this word ; as sulphuret of phosphorus, carburet 
 of iron, &c. The terms bisulphuret, bisulphate, &c., 
 applied to compounds, imply that they contain twice the 
 quantity of sulphur, sulphuric acid, &c. existing in the 
 respective sulphuret, sulphate, &c. 
 
 Viscidity. Glutinous, sticky, like the bird lime. 
 
 Volatilization. The reducing into vapour, or the aeri 
 form state, such substances as are capable of assuming it. 
 
 Way, dry. When the chemist decomposes substances 
 by the agency of heat, he is said to operate in the dry 
 way. 
 
 Way, humid. When the decomposition is produced 
 by water or other fluids, the effect is said to be. produced 
 in the humid way. 
 
 APPARATUS DESCRIBED. 
 
 Acetometer. An instrument for estimating the strength 
 of vinegars. 
 
 Adopter. A chemical vessel with two necks used to 
 combine retorts 1o the cucurbits or matrasses, with 
 retorts instead of receivers. 
 
 JErometer. An instrument for making the necessary 
 corrections in pneumatic experiments to ascertain the 
 mean bulk of the gases. 
 
 Alembic. A chemical utensil made of glass, metal, 01 
 earthenware, and adapted to receive volatile products 
 from retorts. It consists of a body to which is fitted a 
 conical head, and out of this head descends laterally a 
 beak to be inserted into the receiver. 
 
 Mkalometcr. The name of an instrument for deter- 
 mining the quantity of alkali in commercial potassa and 
 soda. 
 
 Mmometer. The name of an instrument to measure 
 the quantity of exhalation from a humid surface in a 
 given time.
 
 46 CHEMISTRY. 
 
 Baiometer. An instrument to determine the weigh! 
 of air; it is commonly called a weather-glass. 
 
 Blow-pipe. A very simple and useful instrument 
 That used hy the anatomist is made of silver or brass, 
 of the size of a common probe, or larger, to inflate ves- 
 sels and other parts. 
 
 The chemical blow-pipe is made of brass, is of about 
 one-eighth of an inch diameter at one end, and the other 
 tapering to a much less size, with a very small perfora- 
 tion for the wind to escape. The smaller end is levelled 
 on one side. Berzelius, in a late excellent treatise on 
 the use of the blow-pipe in chemistry and mineralogy 
 gives the preference to Ghan's construction, with an 
 additional. bent-beak, for a laboratory blow-pipe, and to 
 Wollaston's for a pocket instrument. 
 
 Calorimeter. An instrument by which the whole 
 quantity of absolute heat existing in a body in chemical 
 union can be ascertained. 
 
 Clinometer. An instrument for measuring the dip of 
 mineral strata. 
 
 Crynphorus. The post-bearer, or carrier of cold ; an 
 elegant instrument invented by Dr. Wollaston, to demon- 
 strate the relation between evaporation at low tempera- 
 ture, and the production of cold. 
 
 Crucible. This vessel is employed in the melting of 
 metals, and other operations of fusion. They are made, 
 for low heats, of earthenware or porcelain, but for strong 
 heats, of clay and sand, or clay and powdered .plumbago. 
 Hessian and Dutch crucibles, which are made of refrac- 
 tory clay and sand, are generally the most approved; 
 but modern chemists have an invaluable acquisition in 
 platina, which is often made into crucibles, and will 
 bear, without fusion or injury, a greater heat than any 
 other known substance. 
 
 Cupel. A shallow earthen vessel like a cup, made of 
 phosphate of lime, which suffers the baser metals to pass 
 through it, when exposed to heat, and retains the pure 
 metal. This process is termed cupellation. 
 
 Cucurbits, or matrasses, are glass, earthen, or metallic
 
 CHEMICAL APPARATUS DESCRIBED. 47 
 
 essels, usually of an egg-shape, and open at the top 
 They are used for the purposes of digestion, evapora 
 lion, solution, &c. 
 
 Digester. A strong and tight iron kettle or copper 
 furnished with a valve of safety, in which bodies maj 
 be subjected to the vapour of water, alcohol, or ether 
 at a pressure above that of the atmosphere. 
 
 Eudiometer. An instrument by which the quantity of 
 oxygen and nitrogen in atmospherical air can be ascer- 
 tained. Several methods have been employed, all 
 founded upon the principle of decomposing common air 
 by means of a body which has a greater affinity for thf 
 oxygen. 
 
 Evaporating vessels. These are made of glass, wood 
 metal, porcelain, or Wedgewood's ware. Those of tht 
 last-mentioned composition are very convenient, as the) 
 are, like glass, easily kept clean, and are not very subjecr 
 to crack by changes of temperature. They are gene- 
 rally in the form of shallow basins, and when the mattei 
 deposited in them would be apt to burn to the bottom, 
 and be injured, if not strictly attended to, they are 
 placed over the fire in a vessel filled with sand, which is 
 then called a sand-bath'. When even this heat would 
 prove too great, the heat of boiling water is used instead 
 of sand. 
 
 Furnace. The furnaces employed in chemical opera 
 tions are of three kinds: 1. The evaporatory furnace 
 which has received its name from its use : it is employed 
 to reduce substances into vapour by means of heat, io 
 order to separate the more fixed principles from those 
 which are more volatile. 
 
 2. The reverberator*/ furnace, which name it has 
 eceived from its construction, the flame being prevented 
 
 from rising. It is appropriated to distillation. 
 
 3. The forge furnace. In which the current of air 
 is determined by the bellows. 
 
 Gasometer. Vessels constructed for the retention of 
 gas, and for facilitating the drawing of it off as wanted, 
 -~ '-"- J They are much varied in theu
 
 18 CHEMISTRY. 
 
 construction ; but those on the principle we shall now 
 describe, are amongst the\most simple, and answer per 
 fectly well. They are a cylindrical vessel of glass, or 
 lapanned tin-plate, nearly filled with water, and having a 
 tube in the middle open at the top, and branching at the 
 bottom, through the side of the vessel, to which a stop- 
 cock is attached. Within this vessel, there is another 
 cylindrical vessel, generally of glass, open at the bottom, 
 which is inverted, and suspended by lines which go over 
 pullies, and have weights attached to them, which hang on 
 the outside, to balance the inverted vessel. While the stop- 
 cock at the bottom remains shut, if the vessel be pressed 
 downwards, the air inclosed within it, will remain within 
 in the same situation, on the principle of a diving bell ; 
 but if the cock be opened, and the inverted vessel be 
 pressed down, the air inclosed within it will escape 
 through the cock, and if a blow-pipe be attached to this 
 cock, a stream of the gas may be thrown upon lighted 
 charcoal, or any other body. By means of a graduated 
 rod on the top of the inverted vessel, the quantity thrown 
 out is exactly ascertained ; this rod being so divided as to 
 express the contents of the inner vessel in cubic feet. 
 
 Goniometer. An instrument for measuring the angles 
 of crystals. 
 
 Hydrometer. The best method of weighing equal 
 quantities of corrosive volatile fluids, to determine their 
 specific gravities, appears to consist in enclosing them in 
 a bottle with a conical stopper, in the side of which 
 stopper a fine mark is cut with a file. The fluid being 
 poured into the bottle, it is easy to put in the stopper 
 because the redundant fluid escapes through the notch 
 or mark, and may be carefully wiped off! Equal bulk? 
 of water, and other fluids, are weighed by this means to 
 a great degree of accuracy : care being taken to keep 
 the temperature as equal as possible, by avoiding any 
 contact of the bottle with the hand, or otherwise. The 
 bottle itself shows with much precision, by a rise or fall 
 of the liquor in the notch of the stopper, whether such 
 thange has taken place.
 
 CHEMICAL APPARATUS DESCRIBED. 49 
 
 The hydrometer of Fahrenheit consists of a hollow 
 ball, with a counterpoise below, and a very slender stem 
 above, terminating in a small dish. The middle, or half 
 'ength of the stem, is distinguished by a fine line across. 
 In this instrument every division of the stem is rejected, 
 and it is immersed in all experiments, to the middle of 
 the stem, by placing proper weights in the little dish 
 above. Then, as the part immersed is constantly of the 
 same magnitude, and the whole weight of the hydrom- 
 eter is known, this last weight added to the weights in 
 the dish, will be equal to the weight of the fluid dis- 
 placed by the instrument, as all writers on hydrostatics 
 prove. And accordingly, the specific gravity for the 
 common form of tables, will be had by the proportion : 
 as the whole weight of the hydrometer and its load, 
 when adjusted in distilled water, is to the number 1000, 
 &c., so is the whole weight when adjusted to any 
 other fluid to the number expressing its specific gravity. 
 
 Hypocleptcium. A chemical vessel for separating li- 
 quors, particularly the essential oil of any vegetable, 
 from the water ; and named because it steals, as it were, 
 the water from the oil. 
 
 Hygrometer. The state of the atmosphere, with re- 
 spect to dryness or moisture, is measured by this instru- 
 ment. It is sometimes called hygroscope. 
 
 Mortar. A sort of mould, a vessel to pound in. 
 
 Muffles. In cupellation, it is necessary for the con- 
 tents of the cupel to be exposed to the access of air ; 
 the cupel must not, therefore, be used in a closed fur- 
 nace, or be surrounded with fire. A kind-of small ovens 
 are therefore employed, which are called muffles. They 
 are made of the same material as crucibles, and the 
 cupel being put into them, they are exposed to the heat 
 of the furnace. They are also used in enamelling, and 
 other operations, where heat is required, while the con- 
 tact of the fire must be taken off! 
 
 Pyrometer. As the common mercurial thermometer 
 canno* be employed to ascertain degrees of heat above 
 500 of 650 degrees of Fahrenheit, it is totally inapplica- 
 5 D'
 
 50 CHEMISTRY. 
 
 ble to most of the operations carried on in furnaces and 
 ovens : yet in a variety of manufactures and chemical 
 operations, success depends upon the adjustment of the 
 heat with a degree of nicety -which the most experienced 
 persons are incapable of determining by mere observa- 
 tion. To supply this desideratum, Wedgewood contrived 
 an instrument called a pyrometer, the range of which 
 extends to 32,000 degrees of Fahrenheit's scale. Its 
 utility is derived from the property which clay has of 
 contracting in' proportion to the degree of heat to which 
 it is exposed. This contraction is permanent, and a less 
 degree of heat than that which the clay has experienced, 
 will not alter its dimensions. If, therefore, a piece of 
 clay, of a given bulk, be exposed to the heat of a fur- 
 nace, it may occasionally be taken out, and upon being 
 applied to a gauge, the degree of its contraction may be 
 ascertained, and consequently the greatest heat to which 
 it has been exposed, provided this gauge has been grad- 
 uated by previous experiments. Wedgewood constructed 
 this pyrometer by duly availing himself of these cir- 
 cumstances. 
 
 The pyrometic pieces of clay intended to be used to 
 any given scale, should be exactly of the same composi- 
 tion, as different clays contract in different degrees by 
 the same heat. To guard against the disadvantage of a 
 difference, Wedgewood offered to the Royal Society a 
 bed of Cornish clay, sufficiently extensive to furnish the 
 world for ages. 
 
 The gauge for measuring the diminution which tht 
 pieces of clay suffer from the action of fire, is made of 
 two pieces of brass, twenty-lour inches long, with tht. 
 sides exactly plane, divided into inches and tenths, fixed 
 five-tenths asunder at one end, and three-tenths of an 
 inch at the other end, upon a brass plate ; and the py- 
 rometic pieces are made at first so as just to fit the wider 
 end. The pieces of clay are generally made about one 
 inch long; but if their breadth be just equal to that of 
 the wider end of the gauge, viz. five-tenths of an incli, 
 their dimensions in other respects are not material.
 
 CHEMICAL APPARATUS DESCRIBED. 51 
 
 It is obvious, that in proportion to the shrinking of the 
 clay by heat, it will slide farther and farther towards 
 the narrow end of the converging scale", one side ol 
 which is divided into tenths of an inch ; and every divi 
 sion, of which it contains 240, answers to a 600th part 
 of the breadth of the little piece of clay. One degree 
 of the pyrometer is equal to 130 degrees of Fahrenheit's 
 scale. 
 
 The regular shrinking of clay by heat, does not com- 
 mence at a lower degree than a red heat fully visible in 
 daylight; and this heat is equal to 1077^ degrees of 
 Fahrenheit, or about 500 degrees above the point at 
 which the mercurial thermometer terminates. It be- 
 comes therefore desirable to measure the range of tern 
 perature to which neither of these instruments applies; 
 but nothing has yet been contrived which answers tho 
 purpose in a simple manner. 
 
 The pyrometic pieces of clay should be exposed a> 
 nearly as possible to the same heat as the material, the 
 heat received by which they are intended to measure. 
 For this purpose, they are usually placed close to it, and 
 in the same crucible ; but when the contents of the cru- 
 cible might adhere to them, they are inclosed in a small 
 case, made of crucible clay ; and as they may be re- 
 duced in any degree, while their breadth is retained, the 
 pyrometic piece may generally be introduced without 
 difficulty into any but very small crucibles; and they 
 may be disposed by the side of very small crucibles, with 
 out much hazard of receiving their heat materially soon- 
 er, or with greater intensity than the contents of the 
 crucible. 
 
 The pyrometic piece may be taken out of the fire 
 during any period of the process, and instantly cooled in 
 water, so as to be ready for measuring in the gauge in 
 the space of a few seconds. It will not crack, expand, 
 contract, or sustain any other injury ; and may be imme- 
 diately replaced in the strongest fire, to resume its office 
 of indicating higher degrees of heat than what it has 
 already been exposed to.
 
 52 CHEMISTRY. 
 
 The following table will give a better idea of the 
 heats designated by the pyrometer, than any general 
 remarks : 
 
 Fahr. Wedgw. 
 
 Extremity of the scale of the pyro- 
 meter 32270 240 
 
 Greatest heat of an air furnace, 8 
 
 inches square 21877 160 
 
 Cast-iron melts 17977 130 
 
 Greatest heat of a common smith's 
 
 forge 17327 125 
 
 Welding heat of iron, greatest - - 13427 95 
 Welding heat of iron, least - - - 12777 90 
 
 Fine gold melts 5237 32 
 
 Fine silver melts 4717 28 
 
 Swedish copper melts ..... 4587 27 
 
 Brass melts 3807 21 
 
 Heat by which enamel colours are 
 
 burnt on 1857 6 
 
 Red-heat fully visible in daylight - 1077 
 
 Red-heat fully visible in dark - - 947 1 
 
 Mercury boils 600 
 
 Water boils 212 
 
 Vital-heat 97 7 1 Vo 2 o 
 
 Water freezes 32 
 
 Proof spirit freezes ..... 
 
 The point at which mercury congeals, 
 consequently the limit of the mer- 
 curial thermometers, about - - 40 rf to* 
 
 Wedgewood found by analysis, that the clay of which 
 his pyrometer pieces were formed, consisted of two parts 
 of pure siliceous earth, to three parts of pure argillaceous 
 or aluminous earth. 
 
 The use of the pyrometer shows in a remarkable 
 manner the inaccuracy of the common mode of express- 
 ing the highest degrees of heat by estimation. Thus the 
 heat at which copper melts is called a white heat, though 
 it is only 27 of the pyrometer ; the welding heat of iron, 
 or 90, is also a white heat; even 130, and upwards, is 
 still a wbite heat These examples show very clearly
 
 CHEMICfAL APPARATUS DESCRIBED. 53 
 
 that the temperature of bodies in furnaces is raised in a 
 manner of which we have no idea, unless the materials 
 subjected to it are such as to give us the necessary in- 
 formation. 
 
 Receiver, or recipients. These vessels are usually 
 glass for small operations, for receiving the volatile pro- 
 duct from a retort or alembic ; they are aJapted to the 
 neck of the before-mentioned apparatus, and secured by 
 luting. 
 
 Retorts. These are globular vessels, formed with a 
 long neck, and are made of earthenware, glass, or metal, 
 according to the use for which they are designed. They 
 are used in distillations, and most frequently for those 
 which require a degree of heat superior to that of boil- 
 ing water. The tube of a retort is usually called a beak. 
 
 Glass retorts should be very thin, and of a uniform 
 substance in every part ; otherwise, from the inequality 
 of their expansion, they will crack with the application 
 of a very slight heat : they cannot also be exposed to 
 the fire, unless defended by coating, which is generally 
 some earthy composition. Chaftal particularly recom- 
 mends, for this purpose, fat earth which has been suffer- 
 ed to rot some hours in water ; it must then be kneaded 
 with horse dung, and formed into a soft paste, which 
 must be equally spread over every part of the retort to 
 be exposed to the fire. The adhesion of this coating is 
 such, that should the retort crack during the operation, 
 the distillation may still be carried on. The retorts used 
 over a lamp are not coated. 
 
 Thermometer. The thermometer is a well known 
 instrument for measuring the actual or relative tempera 
 ture of bodies. Its properties are dependent upon the 
 disposition of all bodies to acquire an equal degree of 
 sensible heat or cold, and on the effects of heat in ex- 
 panding some substances, the changes of the dimensions 
 of which are examined by a scale of equal divisions. 
 Mercury expands by heat, and contracts by cold, with 
 greater uniformity than any other known fluid ; it is, 
 therefore, the most proper and the most commonly used 
 5*
 
 54 CHEMISTRY. 
 
 for thermometers, which are constructed in the following 
 manner: 
 
 The first requisite is a glass tube, which may be 
 obtained at the glass house, having a bulb at one end, 
 which, together with part of the tube, is filled with 
 purified mercury,* which, when introduced into the tube, 
 is boiled to expel the air or moisture that might be at- 
 tached to it ; and at the moment it is in ebullition, the 
 extremity of the tube, being drawn to a point by means 
 of a blow pipe, it is hermetically sealed, to prevent any 
 air from entering the tube. Or if the scale be graduated 
 only to 212, the ball is plunged into boiling water, the 
 point to which the mercury ascends accurately marked. 
 For the purpose of graduating the scale, the thermome- 
 ter is plunged into melting ice, and the place where the 
 mercury stands marked. From the freezing to the boil- 
 ing point on Fahrenheit's scale, is 180, or equal parts; 
 and similar parts are taken above and below, for extend- 
 ing the scale. 
 
 Fahrenheit's is the one commonly used in this country, 
 and in Great Britain. The space between the freezing 
 
 * Mercury is generally purified by distillation ; but as this ope- 
 ration may not be convenient to some, I shall mention Dr. Priest- 
 ley's mode of purifying it, which is remarkable for its simplicity, 
 and has an excellent effect Let a strong 10 or 12 ounce phial, 
 with a ground stopper, be a quarter filled with mercury to be puri- 
 fied ; put in the stopper, hold the bottle inverted with both hands, 
 and shake it violently, by striking the hand that supports it against 
 the knee. After twenty or thirty strokes, take out the stopper, and 
 blow into the phial with a pair of bellows, to change the air. If 
 the mercury is not pure, the surface will become black in a short 
 time ; and if very foul, the black coat will appear coagulated. In- 
 vert the phial, stopping it with the finger, and let out the running 
 mercury. Put the coagulated part into a cup by itself, and press 
 it repeatedly with the finger, so as to get out the mercury entan- 
 gled in it. Put both portions of mercury into the phial again, and 
 repeat the process till no more black powder separates. 
 
 After the mercury has been thus purified from its admixture 
 with baser metals, it should be boiled for about half an hour, to free 
 it from the moisture which it is apt to contain. It may then be 
 nearly cooled, when it is ready for the use of thermometers.
 
 CHEMICAL APPARATUS DESCRIBED. 55 
 
 and the boiling points is divided into 180, but the scale 
 begins at that point of temperature which is produced 
 by a mixture of pounded ice and muriate of ammonia, 
 or muriate of soda, which is 32 lower, making the whole 
 distance 212. 
 
 The centigrade thermometer is divided into one hun- 
 dred degrees, between the freezing and boiling points. 
 The freezing point is marked 0, the boiling 100. 
 
 In Reaumur's thermometer, the space between the 
 freezing and boiling points is divided into eighty degrees 
 The freezing point is marked 0, the boiling 80. 
 
 The Russian thermometer, commonly called Delisle's, 
 begins its graduation at the boiling point, and increases 
 to the freezing. The boiling point is marked 0, the 
 freezing 150. 
 
 Ojher fluids, besides mercury, are sometimes used, 
 such as linseed oil and alcohol ; the latter is used partic- 
 ularly for measuring low- degrees of temperature, where 
 mercury would become solid. 
 
 For nice chemical experiments, an air thermometer is 
 sometimes used. The bulb of air thermometers is filled 
 with common air only, and its expansion or contraction 
 is indicated by a small drop of any <jploured liquor 
 which is suspended within the tube, and moves up and 
 down according as the air within the bulb or tube ex- 
 pands and contracts. 
 
 In general, air thermometers, however sensible to the 
 change of temperature, are by no means accurate in 
 their indications.
 
 56 CHEMISTRY. 
 
 Remarks on Apparatus.' 
 
 THE list of chemical apparatus might still be farther 
 enlarged, which are of less general application than 
 those already noticed. It will be evident, that in- a 
 place where, as in a laboratory, several mechanical 
 operations are usually resorted to, that a large strong 
 table or bench is of considerable importance. Conve- 
 nient small tables or blocks of wood, should also be at 
 hand, for supporting mortars, levigating stones, an anvU, 
 &c. A large vice, the use of which implies that oi 
 hammers, rasps, files, saws, and other implements for 
 working wood and metals. Rods of glass, or porcelain, 
 or even clean straws, are used for stirring mixtures in 
 glasses and other vessels. 
 
 It is proper to have a pair of bellows ; shovels, tongs, 
 and pokers, for managing the fire, are of course neces- 
 sary ; and tongs of different shapes, for taking out cru- 
 cibles, muffles, &c., from the furnace, which should also 
 be at hand. 
 
 A plentiful supply of water should also be at hand, 
 together with fuel, and many other things which it is 
 needless to allude to. Distilled water to be used in 
 analyses, and almost all operations which are to be con- 
 ducted with exactness. 
 
 In such a place as a laboratory, where a vast variety 
 of utensils are to be arranged, and where the eye ought 
 to command the situation of every individual article, the 
 arrangement should be such as to be at once commodious 
 and easily maintained. The rule, to let every article 
 have one place, and but one place, is very simple, and 
 the only sure method of keeping good order. 
 
 It ought to be observed, that it is injurious to the ad- 
 vancement of chemical knowledge, to give currency to 
 the idea, that no discoveries, or improvements, can be 
 made without the aid of an extensive and costly appa- 
 ratus. Every chemist should be a good mechanic, and 
 the resources of the mechanic who attends to his pur- 
 suits with his whole will, are often sufficient to enable
 
 SUBSTANCES. 57 
 
 him to accomplish very important ends, at little expense 
 and by very simple means. 
 
 By these, together with a variety of other resources, 
 which are promptly suggested to the active mind, and 
 which will be different with persons in different situa- 
 tions, a demonstration of all the principal facts of chem- 
 istry may be obtained, and new experiments carried into 
 execution, in some instances without any real expense, 
 and in general without much. 
 
 OF SUBSTANCES. 
 
 Meaning of the term simple. 
 
 ALL substances in nature, when classed according tc 
 theii apparent or sensible properties, may be considered 
 either as solid, fluid, aeriform, or ethereal. But they 
 may be distinguished by any of these characters, and 
 yet be either simple or compound ; but to make this dis- 
 tinguishment in the classification of substances, would 
 be incompatible with the design of the present work ; 
 suffice it, therefore, to say in what manner chemists use 
 the term simple. They do not mean by the term simple, 
 that the body to which it is applied is absolutely known 
 to be simple, but merely that it has never been com- 
 pounded, nor is known to be capable of decomposition 
 Hence, a substance at this time called simple, may 
 hereafter, by more improved modes of analysis, be 
 proved a compound. What modern chemists call simple 
 bodies, the ancient chemists call elements, a term which 
 is yet sometimes used. 
 
 The combination of a substance with caloric or light, 
 is not regarded as moving it out of the class of simple 
 bodies, otherwise we could have nothing to denominate 
 simple.
 
 58 CHEMIS TRY. 
 
 OF LIGHT. 
 
 THE nature of light has occupied much of the atten- 
 tion of philosophers, and numerous opinions have beer 
 entertained concerning it. It has sometimes been con- 
 sidered as a distinct substance, at other times as a qual- 
 ity ; sometimes as a cause, frequently as an effect ; by 
 some it has been considered as a compound, by others as 
 a simple substance. Let these considerations be as they 
 may, light has an influence upon almost all bodies which 
 are exposed to it. It is the source of the colour of vege- 
 tables, and in a great measure, if not entirely, of their 
 odour. Plants which grow in darkness are devoid of 
 colour, in which case they are said to be etiolated 01 
 blanched. Gardeners avail themselves of this fact to 
 render vegetables white and tender. Vegetables so sit- 
 uated that the light can only fall freely on one side of 
 them, gradually turn to the light, and chiefly shoot out 
 in that direction. Some whose stems are flexible, follow 
 the coarse of the sun during the day, and alwaj's pre- 
 sent the same face towards him. 
 
 The back, fins, and other parts of fish exposed to light, 
 are coloured, but the belly, which is deprived of light, 
 is always white. 
 
 The vegetable and animal productions of tropical 
 countries, are distinguished by brighter colours than 
 those of higher latitudes. The cause of this phenome- 
 non must be referred to the greater abundance and in- 
 tensity of the light, upon the action of which all colour 
 is dependent. The superior strength of the perfumes, 
 odoriferous fruits, and aromatic resins, of those countries 
 has the same origin. 
 
 All metallic oxides, but especially those of mercury 
 bismuth, lead, silver, and gold, become of a deeper col 
 our by exposure to the rays of the sun ; some of them 
 become perfectly revived, others only partially. The 
 yellow oxide of tungsten, if exposed to the light, loses 
 weight and becomes blue. Green precipitate of iron, 
 exposed to the solar light, also becomes blue.
 
 LIGHT. 59 
 
 Light has a considerable influence on the crystalliza- 
 ion cf salts, many of which will not crystallize without 
 rt Camphor kept in glass bottles, exposed to the light, 
 crystallizes in symmetrical figures on that side which is 
 turned towards the light ; and spirits of wine, water, 
 &c., rising by insensible evaporation in half-filled ves- 
 sels, constantly attach themselves to the most enlightened 
 sides of the vessel. 
 
 It is not to be supposed that these effects are produced 
 by the mere contact of light; on the contrary, we have 
 abundant proofs that light has the power of entering 
 into the composition of bodies, and of being afterwards 
 extricated from them without any alteration. A great 
 number of substances become luminous after having 
 been exposed to light, a property rendered obvious by 
 carrying them instantly from the light to the dark : the 
 diamond is a body of this kind ; indeed, if the human 
 hand be thrust into a strong light, through an aperture 
 in a perfectly dark room, it will, when drawn in, and the 
 aperture closed, be plainly seen, although the other hand 
 is totallv invisible. 
 
 Light is not homogeneous: it is composed of different 
 coloured rays, possessing different refrangibility. The 
 prismatic colours have been divided into seven, viz : red, 
 orange, yellow, green, blue, indigo, and violet. Red Ls 
 the least, and violet the most refrangible. 
 
 The rays of light must be extremely rare, for they 
 cross each other in all possible directions, without the 
 least apparent disturbance. 
 
 The solar rays have been divided into three different 
 kinds. 1. Colorific, or those producing colour. 2. Cal- 
 orific, or those producing heat. 3. Deoxydizing, expel- 
 ling oxygen, and restoring the oxides of metals to their 
 metallic state. 
 
 The different sources from which light is emitted in a 
 visible form, are: 1. The sun and fixed stars. 2. Com~ 
 bustion, which is the act of combination of the combus- 
 tible with oxygen ; of course, the light emitted must 
 *ave existed previously, combined with the combustible
 
 60 CHEMISTRY. 
 
 or with oxygen. 3. Heat ; when the body becomes 
 luminous by being heated in the fire, it is said to be red 
 hot ; and it is found that all bodies that are capable of 
 enduring the requisite degree of heat, without decompo- 
 sition or volatilization, begin to emit light at the same 
 temperature. 
 
 A number of terms are made use of and explained 
 under the science of optics, which might prove instruct- 
 ing. 
 
 OF CALORIC. 
 
 WHAT is denominated heat, is a sensation produced by 
 a substance called caloric, which penetrates all bodies, 
 diminishes the attraction of their several parts, and uni- 
 formly expands their dimensions. 
 
 By means of this powerful agent, solid metals are 
 fused ; liquids rarified ; and almost all substances in na- 
 ture are converted into elastic, compressible, or aeriform 
 fluids. 
 
 It has been asserted by Levoiser, that all bodies, of 
 whatever kind, may exist in three different states, solid, 
 fluid, and aeriform. 
 
 Caloric is found to exist under a variety of forms or 
 modifications. It is said to be free or radiant, and is 
 commonly called heat or temperature; it is that heat 
 which is perceptible to our senses, and affects the ther- 
 mometer, whatever be its degree, or the source whence 
 it is derived. 
 
 Combined' caloric is that which does not affect the 
 thermometer, and is not perceptible by our senses; it is 
 retained in bodies by the force of affinity or attraction, 
 and becomes a part of their substance. 
 
 Heat differs from caloric in this : one is the cause, th 
 other the effect. The latter means that which produce* 
 heat ; while the former is merely the sensation. 
 
 Liquids are combinations of solids with a larger por- 
 tion of caloric than they naturally contain. 
 
 Instruments for pleasuring the relative degrees of heat, 
 are called pyrometers, and thermometers, with suitable 
 scales attached, indicating the degrees.
 
 CALORIC. 6 1 
 
 The states in which bodies exist, admit of different 
 degrees of density or consistence, arising, for the most 
 part, from the different degrees of caloric which they 
 contain. Solids are of different degrees of density, from 
 that of gold to that of jelly ; liquids, from the consist- 
 ence of melted glue, or melted metals, to that of ether. 
 The different elastic fluids are susceptible of different 
 degrees of density. 
 
 Bodies admit of different degrees of consistence with- 
 out changing their state, merely through the agency of 
 caloric. 
 
 According to late theory, caloric is composed of parti- 
 cles perfectly separate from each other, every one of 
 which moves with great velocity in a certain direction. 
 These directions vary infinitely, the result of which is, 
 that there are rays or lines of these particles, moving 
 with immense velocity, in every possible direction. Ca- 
 loric, then, is universally diffused, so that when any por- 
 tion of space happens to be in the neighbourhood of an- 
 other, which contains more caloric, the colder portion 
 receives a portion of the calorific rays from the latter 
 sufficient to restore an equilibrium of temperature. This 
 radiation not only takes place in free space, but -extends 
 also to bodies of every kind. Thus you may suppose 
 that every body whatsoever, is continually sending forth 
 rays, when the body is surrounded with an elastic medium, 
 or in a vacuum. 
 
 These rays are capable of reflection and refraction. 
 
 The manner in which bodies are affected by rays pro- 
 ducing heat, differs in different substances, and is very 
 much connected with their colours. 
 
 Bodies that absorb the most light and of course radiate 
 heat, are heated the most when exposed to solar or ter- 
 r estrial rays. 
 
 Black bodies in general are more heated than red, red 
 more than green, green more than yellow, yellow more 
 than white. 
 
 All bodies are, in a greater or less degree, conductors 
 of caloric. 
 6
 
 62 CHEMISTRY. 
 
 Bodies with respect to caloric are divided into two 
 kinds, good and bad conductors. 
 
 Metals and liquids are good conductors of caloric, but 
 silk, cotton, wool, wood, feathers, &c., are bad conductors. 
 
 A short rod of iron put into the fire at one end, will 
 very soon become hot at the other end ; but a piece of 
 wood or cane of the same length, placed precisely in the 
 same circumstances, may be burnt to ashes at one end., 
 without producing scarcely a sensation of warmth at the 
 other. 
 
 The facility with which bodies are cooled or heated, 
 is in proportion to their conducting power. 
 
 Good conductors both give and receive caloric quicker, 
 and in a given time more abundantly, than bad conduct- 
 ors, which is the cause of their feeling hotter or colder ; 
 though they may be in fact of the same temperature, as 
 indicated by the thermometer. 
 
 In general, the most dense bodies are the best con- 
 ductors of heat ; probably, because the denser the body, 
 the more the number of points that come into contact 
 with caloric. 
 
 Deep lakes are not frozen in winter. This is owing ta 
 the circumstance of cold air being constantly presented 
 to the surface of the lake, which causes a portion of 
 water to lose its temperature, and thus becoming heavier, 
 falls gradually to the bottom, while the warmer water 
 from below ascends, forming a new surface in its place. 
 
 Caloric dissolves water and converts it into steam, by 
 insinuating itself between the particles which are so 
 minutely divided as to become invisible. 
 
 When vapour of boiling water first issues from the 
 vessel, it is invisible, because it is then completely dis- 
 solved by caloric. But when it comes in contact with 
 the cold air, it is condensed, in consequence of a part of 
 the caloric being imparted to the air. The particles of 
 water being in a great measure deprived of their sol- 
 vent, gradually collect, and became visible in the form 
 of steam, and when further deprived of caloric, return 
 *o their liquid state.
 
 OXYGEN. 63 
 
 The atmosphere dissolves water by means of the 
 caloric which it contains. This is called evaporation, 
 and differs from vaporization, which is caused by culi- 
 nary heat. 
 
 The earth being a great radiator of caloric, parts with 
 its heat more readily than air. When the solar heat 
 declines and entirely ceases in the evening, the earth 
 rapidly cools by radiating heat towards the skies; whilst 
 the air has no means of parting with its heat, but by 
 coming in contact with the cool surface of the earth, to 
 which it communicates its caloric. The solvent power 
 being thus reduced, the water is deposited in small drops 
 called dew. 
 
 / OF OXYGEN 
 
 OXYGEN is the name given to the solid particles of 
 oxygen gas, which is a combination of oxygen, caloric, 
 and light, and is the simplest form in which oxygen can 
 be obtained. Oxygen is called the radical or base of the 
 gas ; and the same mode of expression is used in other 
 cases. 
 
 Oxygen gas was discovered by Dr. Priestley, on the 
 1st of August, 1774. It is invisible, perfectly elastic like 
 common air, and possesses neither taste nor smell. It is 
 740 times lighter than water. Its weight to atmospheric 
 air, is as 1 103 to 1000. 
 
 Oxygen has never been procured in an uncombined 
 state. Its greatest purity is that of gas. It is not made 
 solid by any degree of cold, and therefore differs in this 
 respect from vapours which may be condensed into a 
 liquid, and converted into a solid. 
 
 Oxygen enters into chemical combination with a great 
 number of substances, in which it exists in a concrete or 
 solid state ; it is by the application of heat, or of acids, 
 to some of the substances containing it, that it is usually 
 procured in the form of gas. 
 
 Oxygen gas may be obtained with the greatest facility 
 and purity, from hyper-oxy muriate of potass. A small 
 retort must be partly filled with this salt, and exposed
 
 64 CHEMISTRY. 
 
 to the heat of a lamp ; the salt melts, and oxygen u 
 extricated in abundance, as it is held by this singular 
 substance in a state of great concentration, and by a 
 very weak affinity. 
 
 Ingenhouz obtained from four ounces of nitrate of 
 potass, melted with a little slacked lime, 3000 cubic 
 inches of this gas. Let any quantity of this salt be put 
 into an earthern or iron retort, to the extremity of which 
 is adapted a bent tube, terminating in the pneumati 
 trough. The retort must be gradually made red-hot 
 when the oxygen gas will be rapidly disengaged, and 
 will be very pure. 
 
 When considerable quantities of oxygen are required, 
 the black oxide of manganese is most frequently used, 
 as it is the cheapest article that can be employed, and 
 supplies the gas in a good degree of purity. The 
 manganese is put into a retort, which is made red-hot, 
 and the gas is collected by the pneumatic apparatus, as 
 in using nitrate of potass. One pound of the best 
 manganese will yield upwards of 1400 cubic inches of 
 the gas. The retort is easily cleared of the manganese 
 when the experiment is ended ; and if the manganese 
 that has once been used, be exposed to the air for some 
 time, it will serve again; but the cheapness of the arti- 
 cle renders this of litcle consequence. 
 
 Red oxide of mercury, and of lead, yield oxygen in 
 the same manner as manganese. ' 
 
 Oxygen gas is the only one that can be breathed by 
 animals for any length of time with impunity. The 
 power of atmospheric air in supporting respiration, is 
 owing to the oxygen. 
 
 In respiration, a quantity of atmospheric air is taken 
 into the lungs; the oxygen disappears, and a quantity of 
 carbonic acid gas, equal in bulk, is formed in its stead. 
 A reciprocal influence is exerted between this aerial 
 fluid and the circulating blood ; and the continuance of 
 life is dependent upon the due exercise of this influence; 
 wlvch appears by the conversion of oxygen into carbonic 
 cid.
 
 OXYGEN. 6f> 
 
 Animals confined in oxygen gas will live four or five 
 limes longer than when confined in atmospheric air. 
 
 It may be breathed by men for some time, without 
 producing any qther effect than a sensation of warmth 
 and slight stricture of the chest. 
 
 Oxygen forms about 22 per cent, of the atmospheric 
 air: the rest is nitrogen or azotic gas, except a smal 
 quantity of carbonic acid. 
 
 Oxygen combines with all the metals ; and in that 
 state, they are called metallic oxides, depriving them of 
 their metallic lustre, and giving them an earthy or rusty 
 appearance. 
 
 Some of the metals become oxidized, or are rusted by 
 mere exposure to the damp atmosphere. 
 
 Iron, exposed to the weather, soon becomes rusty, by 
 attracting oxygen from the air or water. 
 
 All oxides are heavier than the metal, in proportion 
 to the quantity of oxygen with which they are com- 
 bined. 
 
 Many of the metals are capable of combining with 
 different proportions of oxygen. Those with one propor- 
 tion are called protoxides ; of two, deutoxides ; those of 
 three, tritoxides. 
 
 A metal combined with the greatest proportions of 
 oxygen is called peroxide. 
 
 Oxygen has a powerful effect on vegetable colours, 
 producing the various tints of shade which we behold in 
 this department of nature. 
 
 Yarn, when taken from the blue vat, is green, but, on 
 exposure to the air, it imbibes oxygen, and is changed to 
 a blue. 
 
 It is well known to the dyers, that they cannot produce 
 a good black without exposing their stuffs to the air. 
 
 Vegetable colours fade on exposure to the sun, which 
 is probably owing to this principle : the oxygen which 
 previously existed in the colouring matter in a solid form, 
 is rendered aeriform by the jraysof the sun, and is evolved 
 in the form of gas. 
 
 6* E
 
 66 CHEMISTRY. 
 
 OF NITROGEN. 
 
 NITROGEJC is the basis of the nitric acid. It exhibits 
 tself in its simplest state as a gas. It was formerly called 
 azote, because it was destructive to animal life. 
 
 Nitrogen gas is most easily described by including 
 many of its negative qualities. It has no taste ; it neither 
 reddens vegetable Blue colours, nor precipitates lirne- 
 \vater ; it is not absorbed by water. It unites to oxygen 
 in several proportions; it also unites to hydrogen. 
 Though incapable of being breathed above its base, 
 nitrogen is a component portion of all animal substances 
 It is lighter than oxygen. Dr. Black found that a vessel 
 of 1000 cubical inches, which will contain 315 troy grains 
 of atmospheric air, will contain 335 of oxygen gas, but 
 only 297 of nitrogen gas. 
 
 Nitrogen gas may be variously obtained. If the oxy- 
 gen be extracted from the atmospheric air, this substance 
 will remain, and will generally be very pure, unless the 
 oxygen has been extracted by respiration. If iron tilings 
 and sulphur, moistened with water, be put into a jar 
 containing atmospherical air, this gas will, in a day or 
 two be all the air that remains in the jar, as the oxygen 
 will be absorbed by the iron and sulphur. Phosphorus, 
 or sulphuret of lime or potass, inclosed with common air 
 in a jar, will produce a similar effect 
 
 Nitrogen gas may likewise be obtained from animal 
 substances. For this purpose, put some small pieces of 
 lean muscular flesh into a retort, and cover them with 
 weak nitric acid. The heat of a lamp will extricate 
 the gas, which may be collected by the pneumatic 
 apparatus. 
 
 It has been conjectured that nitrogen is not a simple 
 substance, but no experiments have decisively proved this. 
 
 Atmospherical air contains 78 parts in the 100, by 
 measure of nitrogen gas ; the 22 remaining parts, or 
 oxygen, being thus largely diluted, becomes proportion- 
 ately less intense in its stimulating effects, and fit for the 
 Diirposes of life, the length of which is increased by this
 
 HYDROGEN. 67 
 
 source of moderation in its course. By mixing pure 
 nitrogen gas and oxygen gas in the proportions just men 
 ioned, a gas having all the properties of atmospherical 
 air is the result. 
 
 Though animal life cannot be sustained for a moment 
 by nitrogen gas, yet it is congenial to vegetables, and 
 appears to be a part of their food ; they derive it from 
 its combinations with oxygen in atmospherical air. 
 
 OF HYDROGEN. 
 
 THE third and last substance, which, in its simplest 
 form, can only be obtained in an aerial state, is called 
 hydrogen. This gas has long been generally known by 
 the name of inflammable air ; it is the gas which miners 
 call fire damp. 
 
 Hydrogen with oxygen forms water; and it is by the 
 decomposition of water that chemists obtain it in the 
 greatest abundance and purity. For this purpose, iron 
 Tilings or turnings, or granulated zinc, are put into a 
 retort, and covered with sulphuric acid diluted with foui 
 times its weight of water. A violent effervescence 
 ensues, a large quantity of gas is evolved, and issuing 
 from the retort, is collected in the usual manner by the 
 pneumatic apparatus. In this experiment, the acid is 
 not decomposed ; it is the oxygen of the water with 
 which the acid is diluted, that seizes upon and oxidizes 
 the metal, and the hydrogen in the same portion of 
 water being then disengaged, passes over in the state of 
 gas. The hydrogen obtained by using zinc is the purest ; 
 that obtained by using iron generally containing some 
 carbon. 
 
 The process just described is the readiest for obtaining 
 this gas, but it is evolved in every instance in which 
 metals are tarnished or rusted by moisture, and it may 
 be obtained in great quantities, by causing the vapour 
 of water to pass through an iron tube, or through a tube 
 of any kind, containing a coil of iron wire, heated to 
 ignition. The operation is generally conducted by thf
 
 68 CHEMISTRY. 
 
 use of a furnace., provided with small holes opposite each 
 other, to admit the tube to pass through it. 
 
 Hydrogen, like oxygen and nitrogen, is invisible, elastic, 
 and inodorous; but the last quality it seldom possesses, 
 because it is very seldom perfectly dry, and when it con- 
 tains water in solution, like alkaline sulphurets, its odour 
 is considerably fetid. It generally contains half its weight 
 of water, and when it is received over water, its volume 
 is one-eighth larger than when received over mercury. 
 
 Hydrogen gas is the lightest of all substances, except 
 light and caloric. When pure, it is nearly 13 times 
 lighter than common air. It is this extreme levity 
 which occasions its utility for inflating balloons. 
 
 Hydrogen gas is incapable of supporting life, but may 
 be inhaled and exhaled a few moments without fatal 
 effects ; it is returned by the lungs unaltered, and does 
 not therefore appear to be positively noxious, but only 
 operates by excluding oxygen. 
 
 Although so currently called inflammable air, hydrogen 
 gas is not capable of being burned, or of supporting 
 combustion, unless oxygen be present. 
 
 That water is in reality the union of oxygen and 
 hydrogen, is proved not onlv by these gases being ob- 
 tained by its decomposition, but by reversing the experi- 
 ment and producing water from the gases themselves. 
 Fifteen parts, by weight, of hydrogen, being mixed with 
 85 parts of oxygen, and retained in a close vessel, if the 
 hydrogen be fired by the electric spark, the gases will 
 be converted into water, the weight of which will be 
 equal to both the gases employed, and the gases disap- 
 pear. 
 
 The oil and resin of vegetables are derived from the 
 decomposition of water ; and composts are partly bene- 
 ficial as manures, from the hydrogen furnished in the 
 process of putrefaction : if the compost be kept till this 
 putrefaction is nearly over, its value is materially lessened 
 as the hydrogen flies off. 
 
 Hydrogen combines with a larger quantity of oxygen 
 ihan any other body ; its combustion, therefore when
 
 HYDROGEN. 69 
 
 mixed with oxygen, produces a more intense heat than 
 any other combustion. This mav be shown with a blad- 
 der filled with oxygen, and another with hydrogen, by 
 causing a stream from each bladder to pass through a 
 tube upon a piece of ignited charcoal, or any other 
 burning combustible. Each of the bladders should be 
 furnished with a stop-cock, and as there is some risk of 
 a violent explosion, bladderg may be used with more 
 propriety than any other vessels. 
 
 Hydrogen is capable of combining with sulphur, phos- 
 phorus, carbon, and arsenic; and these compounds are 
 respectively distinguished by the terms sulphuretted hy- 
 drogen, phosphuretted hydrogen, carburetted hydrogen, 
 and arseniated hydrogen. The flame which it yields in 
 combustion is differently tinged, according to the sub- 
 stance combined with it. Fireworks have been con- 
 structed, in which the diversity of colour in the flame 
 was produced by an attention to this property. 
 
 Pit-coal, by distillation, affords carburetted hydrogen, 
 which is employed in what are called the gas lights. 
 The coal thus distilled is not lost, but is converted into 
 coke, which is as valuable as the coal from which it was 
 produced. 
 
 Sulphuretted hydrogen has an offensive smell, resem- 
 bling rotten eggs. It is produced by dissolving the sul- 
 phurets in acids: that disengaged by the sulphuric acid 
 burns with a bJue flame; that produced by the nitric 
 acid burns with a yellowish white flame ; the lattei acid 
 disengages the largest quantity of the gas. 
 
 Phosphuretted hydrogen, wFu'ch has also a strong fetid, 
 putrid smell, may be obtained by boiling in a retort a 
 little, phosphorus with a solution of potass. If this gas 
 comes in contact with the air as it escapes from the re- 
 tort, it takes fire, and a dense conical wreath of smoke 
 arises from it. It explodes if suddenly mixed with oxy- 
 gen, oxymuriatic acid, or nitrous oxide gas. The ignis 
 fatuus, or jack-with-a-lantern, is attributed to this disen- 
 gagement of the g^as from the putrid effluvia common 
 in swampy places where that phenomenon is observed.
 
 70 
 
 CHEMISTRY. 
 
 Arseniated hydrogen may be obtained by adding sul- 
 phuric acid, diluted with twice its weight of water, to 
 four parts of granulated zii.c and one of arsenic. Two 
 parts of this gas, with one of oxygen, will explode loud 
 I?, and the products are water and arse.iious acid. 
 
 OF SULPHUR. 
 
 / 
 
 SULPHUR, or brimstone, is a well-known substance, of 
 a yellow colour, brittle, moderately hard, devoid of smell, 
 but not entirely so of taste. Its specific gravity is 1990. 
 It is a non-conductor of electricity, and therefore becomes 
 electric by friction. 
 
 Sulphur is extremely disseminated, and is obtained 
 abundantly, both in a state of purity, and from its com- 
 binations with other substances. It flows from volcanoes, 
 and is sublimed from the earth in some parts of Italy. 
 It is combined more or less frequently with most ores, 
 and is procured in large quantities from some of them, 
 particularly those of iron and copper. In the Isle of 
 Anglesea, it is sublimed c from the copper ore, and collect- 
 ed in large chambersj 3 ^vhich are connected with the 
 kilns by means of horizontal flues. 
 
 Sulphur unites with most of the metals, rendering them 
 brittle, and increasing their fusibility. It is soluble in 
 oils, and by heat in alcohol, but water has no immediate 
 action upon it Hydrogen gas dissolves it, and is then 
 called sulphuretted hydrogen. Tnlfe gas is evolved dur- 
 ing the putrefaction of animal substances. Sulphur 
 unites with phosphorus by heat; but with charcoal it 
 does not combine. 
 
 If a bar of iron or steel, at a white heat, be rubbed 
 with a roll of sulphur, the two bodies combine and drop 
 down together in a fluid state, forming sulphuret of iron, 
 a compound of the same kind as the native sulphuret of 
 iron called pyrites, and which, from its abundance, sup- 
 plies much sulphur. 
 
 If potass or soda be melted by a moderate heat, with 
 equal parts of sulphur, in a covered crucible, it forms a
 
 CARBON. 7J 
 
 substance, which, after cooling, is of a liver-brown col 
 our. These compounds are respectively called the 
 sulphuret of potass or soda. 
 
 Orpiment, or king's yellow, is a sulphuret ; it is com- 
 posed of arsenic and sulphur Vermilion is the red 
 sulphuret of mercury. 
 
 Sulphur sublimes at the heat of 170, and is collected 
 in the form of what is called flowers of sulphur. If 
 heated to 185, it becomes very fluid, but by a continu- 
 ance of the heat its fluidity diminishes, and it even be- 
 comes thick ; on being allowed to cool, its former fluidity 
 returns before it becomes solid. If as soon as the 
 sulphur has begun to congeal, the inner liquid part be 
 poured out, the internal cavity will exhibit long needle- 
 shaped crystals of an octahedral figure. 
 
 Sulphur combines with oxygen in four definite propor- 
 tions, forming an interesting class of acids, viz : the 
 sulphurous, hypo-sulphurous, sulphuric, and hypo- 
 sulphuric. From these combinations it is inferred that 
 its prime equivalent is 2, and the density of its vapour is 
 1.111, equal to that of oxygen. 
 
 Sulphur is applied to many important uses. It is em- 
 ployed in medicine, it enters into the composition of 
 sulphuric acid, of gunpowder, and of the common com- 
 position for paying the bottom of ships. Its fumes are 
 employed in bleaching silk and wool, and checking the 
 progress of vinous fermentation. Common matches, for 
 lighting fires, are tipped with sulphur. 
 
 OF CARBON. 
 
 VEGETABLES, when burnt or distilled in close vessels, 
 (ill their volatile parts are entirely separated, leave a 
 black, brittle, and cinerous residuum, which constitutes 
 the greater part of the woody fibre, and is called char- 
 coal. Charcoal contains a portion of earthy and saline 
 matters, but when entirely freed from these and other 
 impurities, a solid, simple, combustible substance remains, 
 which is called carbon.
 
 72 CHEMISTRY. 
 
 Carbon exists naturally in a state of greater purity 
 than it can be prepared by art. The diamond is pure 
 carbon crystallized. The diamond, when pure, is colour- 
 less and transparent. It is the hardest substance known 
 and, as it sustains a considerable degree of heat un- 
 changed, ft was formerly supposed to be incombustible. 
 It may, however, be consumed by a burning-glass, and 
 even by the heat of a furnace. The difficulty of burn- 
 ing it appears to arise from its hardness; for Morveau and 
 Tennant have rendered common charcoal so hard by ex- 
 posing it for some time to a violent fire in close vessels, 
 that it endured a red heat without catching fire. Com- 
 mon charcoal contains only 64 parts of diamond, or pure 
 carbon, and 36 of oxygen in every 100. 
 
 The common charcoal of commerce is usually pre- 
 pared from young wood, which is piled up near the 
 place where it is cut, in conical heaps, covered with 
 earth, and burnt with the least possible access of air. 
 When the fire is supposed to have penetrated to the cen- 
 tre of the thickest pieces, it is extinguished by entirely 
 closing the vents. When charcoal is wanted very pure, 
 the product of this mode of preparing it will not suffice ; 
 for the manufacturing of the best gunpowder, it is dis- 
 tilled in iron cylinders. Chemists prepare it in small 
 quantities, in a crucible covered with sand ; and, after 
 they have thus prepared it they pound it, and wash away 
 the salts it contains by muriatic acid ; the acid is removed 
 by the plentiful use of water, and afterwards, the char- 
 coal is exposed to a low red heat. Pure charcoal is per- 
 fectly tasteless, and insoluble in water. 
 
 Charcoal, newly prepared, absorbs moisture with 
 avidity. It also absorbs oxygen, and other gases which 
 are condensed in its pores, in quantity many times ex 
 ceeding its own bulk, and are given out unaltered 
 Fresh charcoal, allowed to cool without exposure to air, 
 and the gas then admitted, will absorb 2.25 times its 
 bulk of atmospheric air immediately, and .75 more in 
 four or five hours; of oxygen gas, about 1.8 immediately 
 and slowly, 1 more ; of nitrogen gas, 1.65 immediately
 
 CARBON. 73 
 
 of nitric oxide, 8.5 very slowly ; of h} drogen gas, about 
 1.9 immediately; carbonic acid gas, 14.3 immediately. 
 The greater part of these gases are expelled by a heat 
 below 212, and a portion even by immersing the char- 
 coal in water. These absorptions are promoted by a 
 low temperature ; but, at an elevated temperature, char- 
 coal has such an affinity for oxygen, that it will abstract 
 it from almost all its combinations. Hence, its utility in 
 reviving metals. 
 
 Fossil coal, and all kinds of bitumen, contain a large 
 quantity of carbon : it is also contained in oils, resins, 
 sugar, and animal substances. 
 
 Charcoal is one of the most unchangeable substances ; 
 if the access of air be prevented, the most intense heats 
 have no other effect than that just mentioned of harden- 
 ing it, and rendering its colour a deeper black. Insolu- 
 able in -.vater, and incapable of putrefaction, it under- 
 goes no change by mere exposure or age; and stakes, 
 and other materials of wood which have been charred, 
 or superficially converted into charcoal, have been pre- 
 served from decay for thousands of years ; the ancients 
 availed themselves of this mode of preparing stakes which 
 were to be driven into the ground for foundations and 
 other purposes. 
 
 The combinations of carbon with various substances, 
 are called carburets. Steel is a combination of iron and 
 carbon, in which the proportion of carbon is very small, 
 only about a two hundredth part ; it is to its carbon that 
 it owes its valuable property of admitting to be temper- 
 ed. Cast-iron contains more carbon than steel, but this 
 difference is not the only cause of the difference of the 
 properties of iron in the two states; from its carbon, 
 however, cast-iron admits of being made hard or soft, 
 nearly in the same manner as steel. Plumbago contains 
 90 parts of carbon, and but ten of iron ; it is from this 
 excess of carbon, called a hyper-carburet of iron. The 
 name of black lead, by which it is most generally known, 
 is evidently improper, as it contains not a particle of 
 lead. On the contrary, the connexion of plumbago with 
 7
 
 74 CHEMISTRY. 
 
 iron might be inferred from ks resemblance in some 
 respects to that kind of cast-iron which contains most 
 carbon; their fracture is much alike; and very fine 
 filings of the iron tinge the hands nearly in the same 
 manner as the powdered plumbago. Yet cast-iron sel- 
 dom contains more than a forty-tifth part of its weight 
 of carbon. 
 
 Charcoal possesses the singular property of combmirg 
 with, and destroying the odour,.colour, and taste, of va- 
 rious substances. Putrid and stinking water may oe 
 rendered sweet by filtering it through charcoal-powder, 
 or even by agitation with it. Common vinegar boiled 
 with charcoal-powder, becomes perfectly limpid. Saline 
 solutions that are tinged yellow or brown, are rendered 
 colourless in the same way, so that they will afford white 
 crystals. Malt spirit may be freed from its disagreeable 
 flavour by distillation with about r ^ of its weight of 
 charcoal. Tainted vessels, after having been well scoured, 
 may have every remaining taint removed by rinsing 
 them with charcoal-powder ; and this powder will also 
 restore the sweetness of flesh-meat but slightly tainted 
 with putridity. As a dentrifice, charcoal in the state of 
 an impalpable powder, is unrivalled, at once whitening 
 the sound teeth, and sweetening the breath by neutrali- 
 zing the fetor that arises from those which are carious, 
 or from a scorbutic state of the gums. 
 
 When charcoal is burnt in oxygen gas, nearly the 
 whole of it disappears: it is converted by its combina- 
 tions with oxygen into an aeriform fluid, which, having 
 the properties of an acid, is called carboni& acid gas. 
 It contains 28 parts, by weight, of charcoal, and 72 of 
 ftxygen in every 100. It was discovered by Dr. Black, 
 in 1755, and the discovery constitutes a memorable 
 epoch in the history of chemistry, as it was attended 
 with so clear a demonstration of the fact, that gaseous 
 substances could become concrete, or form a part of solid, 
 substances, and that, on the contrary, solid substance* 
 unild assume the gaseous form. 
 
 Carbonic acid gas is nearly twice as heavy as atm<
 
 CARBON. 75 
 
 spheric air, and it may therefore be poured from one ves- 
 sel to another, or retained in a cask and drawn off like 
 other liquors. Though invisible, yet if contained I-n a 
 glass, the presence of something different from common 
 air may be discovered by lighting a piece of paper, and 
 putting it into a glass ; the light will instantly go out, 
 and the smoke becoming entangled in this heavy gas, 
 will show the quantity of the gas that may be present. 
 The extinction of fire by this gas is instant and com- 
 plete ; and when by any accident it is breathed, it pre- 
 vents the power of speech, and rapidly destroys life. 
 As it is evolved in the process of fermentation, it is often 
 present in vats, and the public journals frequently record 
 instances of persons who have incautiously descended 
 into these vessels to clean them, perishing from its bane 
 ful effects in a few moments. 
 
 Carbonic acid gas is always the result of the combus 
 tion of charcoal, which cannot be burnt in a close apart 
 ment, without imminent hazard of suffocation to the 
 persons present. This gas is often contained in deep old 
 wells, and places which have been long closed ; wherever 
 it is suspected to exist, it will be proper to introduce a 
 lighted candle, and if J.hat burns as usual v no danger need 
 be apprehended ; but if it be extinguished, it may be 
 taken for granted that the air is unfit to breathe. A 
 quantity of water, particularly if mixed with quick-lime, 
 will, if thrown into a suspected place, absorb the car- 
 bonic acid which may be present. Carbonic acid gas 
 constitutes what miners call choke-damp. 
 
 Carbonic acid, though so deleterious when breathed, 
 often forms a palatable wholesome ingredient in food, as 
 it possesses the strongly antiseptic properties of carbon, its 
 base. Hence the acid taste of Pyrmont, Spa, and other 
 mineral waters ; hence the sparkling and agreeable brisk- 
 ness of fermented liquors, such as beer, cider, &,c. Yeast, 
 from the large quantity it contains of it, has performed 
 wonderful cures in putrid diseases. The atmosphere 
 contains a very small quantity of this gas, the use of 
 wHch may be to neutralize the putrid miasmata con-
 
 76 CHEMISTRY. 
 
 tinually flying aoout. Water may by pressure be cans 
 ed to combine with nearly three times its own bulk of 
 carbonic acid gas. 
 
 The combinations of carbonic acid with other substan- 
 ces, are called carbonates. Common ch^ik, limestone, 
 and marbles, are all carbonates, and in their chemical 
 composition differ but little from each other. Carbonic 
 acid gas may be obtained from any of these, by putting 
 them into a retort in powder, and pouring upon them a 
 diluted acid, for example the sulphuric. The gas must 
 be collected by the pneumatic apparatus. A cubical 
 inch of marble contains as much carbonic acid, as, in the 
 state of gas, would fill a vessel of six gallons. 
 
 OF PHOSPHORUS. 
 
 PHOSPHORUS is a yellowish, transparent substance, of 
 the consistence of wax. It is luminous in the dark at 
 common temperatures, and at 67 it emits a white 
 smoke. It is rapidly consumed at 122. It is preserved 
 by keeping it in water : the water has, however, the 
 effect of rendering it opaque ; and even exposure to light 
 alters it in some degree. 
 
 Phosphorus was originally prepared from urine, by a 
 tedious and disagreeable process ; but Gahn, a Swedish 
 chemist, having discovered that it existed in bones, it is 
 now prepared from this class of bodies. The bones are 
 calcined till they cease to smoke, after which they are 
 reduced to a fine powder. This powder is put into a 
 glass vessel, and sulphuric acid is gradually goured upor 
 it, till the further addition of acid occasions no extrica 
 tion of air bubbles. This mixture is largely dilutee 
 with water, well agitated, and kept hot for some hours, 
 it is then filtered, and afterwards evaporated slowly, till 
 a quantity of white oowder falls to the bottom. This 
 powder, by a second alteration, is separated, and thrown 
 away. The evaporation is then lesumed; and when- 
 ever an- white powder appears, the alteration must be 
 repeated, in order to separate it. During the whole pro
 
 PHOSPHORUS. 77 
 
 cess, what remains on the filter must be washed with 
 pure water, and this water added to the liquor. The 
 evaporation is continued till all the moisture disappears, 
 and nothing but a dry mass remains. This mass is put 
 into a crucible, and kept melted in the fire, till it ceases 
 to yield a sulphurous smell; it is then poured out 
 When cold, it resembles a brittle glass: it is pounded in 
 a glass mortar, and mixed with one third, by weight, of 
 charcoal dust. This mixture is put into an earthenware 
 retort, to which is adapted a receiver, containing a little 
 water. In a short time after the retort and its contents 
 have become red-hot, the phosphorus passes into the re- 
 ceiver, drop by drop. It is generally formed into small 
 cylinders, by moulding it under lukewarm water, in 
 glass tubes, or by putting a cork into the extremity of the 
 pipe of a glass funnel, into which hot water may then be 
 poured, and the phosphorus being dropt in, will mould 
 itself. From the remark made above, respecting the 
 low temperature at which it burns, it is necessary to 
 take great care that none of it adheres to the hand, 
 especially under the nails, whence it would be with 
 difficulty extracted ; as the heat of the body would kin- 
 dle it, and it burns with extreme ardour. If, however, 
 it be thoroughly mixed with several times its bulk of 
 hog's lard, it may be held in the hand without injury. 
 
 Phosphorus possesses a prodigious divisibility. A quar- 
 ter of a grain being administered in some pills to a per- 
 son who was afterwards opened, all the internal parts 
 were found to be luminous, and even the hands of the 
 person who opened the body had the same appearance. 
 
 Phosphorus combines with oxygen, hydrogen, nitrogen, 
 sulphur, most of the metals, and some of the earths. By 
 combining with oxygen, that is, after combustion, it 
 forms phosphoric acid. When the phosphoric acid is 
 combined with any substance, that substance is called a 
 phosphate. The phosphorus in bones is in a state of 
 phosphate of lime. The combination of phosphorus with 
 iron forms that kind of iron called cold-short, which is 
 brittle when cold, though malleable when heated. 
 7*
 
 78 CHEMISTRY ' 
 
 Phosphorus, rubbed in a mortar with iron fi'.ings, takes 
 fire immediately. Phosphoric match-bottles are pre- 
 pared by mixing one part of flour of sulphur with eight 
 of phosphorus. If a very small quantity of this mixture 
 be taken out on the point of a match, and rubbed upon 
 a cork, or any similar body, the match becomes lighted. 
 
 At the temperature of 70 F., phosphorus combines 
 with oil, and forms a compound, which, in contact with 
 atmospheric air, becomes luminous in the dark. 
 
 Put one part of phosphorus into six parts of good olive 
 oil, or oil of cinnamon, which is preferable. Digest it in 
 a gentle sand heat, until the phosphorus is dissolved, on 
 which, immediately cork the bottle. If this oil be rubbed 
 on any thing, it immediately becomes luminous in the 
 dark, and yet has not sufficient heat to burn the sub- 
 stance. 
 
 OF WATER, 
 
 THE composition of water has already Been inciden- 
 tally mentioned; it consists of 85 parts of oxygen, and 
 15 of hydrogen. It is a product of combustion, being 
 formed whenever hydrogen is united to oxygen ; for these 
 two bodies are not known to be capable of uniting in any 
 proportion but that which forms water. The proofs of 
 the composition of water are complete; this fluid may 
 be decomposed, that is, separated into the gases of which 
 it is composed ; or the gases may be converted into water. 
 
 Water is capable of existing in four diiFerent states, 
 1. that of ice ; 2. that of water, or the liquid state ; 3. that 
 of steam, or the gaseous state; 4. in combination with 
 crystals or other solids. 
 
 1. Ice is the simplest state of water; if entirely de 
 prived of caloric, it would still be ice, only increasing in 
 hardness as the caloric was abstracted. It is elastic, and 
 when long kept much below the point at which it is 
 formed, it becomes extremely hard. When pulverized, 
 it is white. As one of the amusements of the court of 
 Russia, in the severe winter of 1740, a palace was con- 
 strucv^d entirely of ice hewn from the river Neva ; and
 
 'WATER. 79 
 
 a cannon made of the same material, drove a hempen 
 bullet through a hoard two inches thick at the distance 
 nf sixty paces. Water expands in passing to the state 
 of ice, with a force that produces most astonishing 
 effects; rending trees, and separating immense fragments, 
 from the rocks and mountains. This expansion is owing 
 to the new arrangement of its particles; the needles of 
 the crystals crossing each other, either at angles of 60 
 or 120. Ice is converted into water when its tempera 
 ture is raised above 32. 
 
 2. Water retains its character as a fluid, at all tem- 
 peratures between 32 and 212. It is employed as the 
 standard of comparison in all tables of specific gravities. 
 
 Water, when perfectly pure, possesses a high degree 
 of transparency, and is entirely destitute of colour, taste, 
 and smell. It is nearly inelastic, and consequently incom- 
 pressible. It can only be obtained pure by distillation; 
 for as it is capable of holding a greater number of sub- 
 stances in solution than any other fluid, the facility with 
 which it becomes impregnated with foreign substances 
 must be obvious. 
 
 3. When water is converted into vapour, it combines 
 with above five times the quantity of caloric which would 
 be required to bring ice-cold water to the boiling heat ; 
 it is estimated to fill a space 1800 times greater than in 
 the state of water; and the large quantity of caloric 
 with which it is combined, is the only cause of the differ- 
 ence. This refers to water under the common pressure 
 of the atmosphere. When this pressure is lessened, as 
 under an exhausted receiver, water assumes the state of 
 vapour at a very gentle heat; and when retained in a 
 sufficiently strong vessel, as in Papin's digester, it may be 
 rendered red-hot without being converted into steam. 
 The elasticity of steam is prodigious ; and it increases 
 with the heat at which the steam is formed. It has been 
 found by experiments, that the expansive force of steam 
 exceeds that of gunpowder. 
 
 4. The singular tenacity with which water is held 
 by a great number of substances, is an interesting fact
 
 80 CHEMISTRY. 
 
 Saussure has p:oved that alumine will retain one-tenth 
 of its weight of water, at a heat which will keep iron in 
 fusion ; lime retains water with nearly the same force; 
 and calcined plaster of Paris is changed from a state ol 
 powder to that of a solid, by combining with a large 
 portion of water ; some salts, though tolerably hard and 
 dry, are combined with as much water, as at a boiling 
 heat would hold them in solution; crystals owe their 
 transparency, and even their solidity, to the water com- 
 bined with them, for they lose both these properties as 
 soon as the water is abstracted. By entering into many 
 of these combinations, it is evident that water is deprived 
 of a greater quantity of caloric than in a state of ice, 
 and it is to this cause that we must attribute its hardness 
 in gems. 
 
 MINERAL WATERS. 
 
 The purest water which nature affords is melted 
 snow, or of rain newly fallen, and collected in open 
 fields, at a distance from houses, or contaminated atmo- 
 sphere. The water of rivers and lakes is next in puriiy, 
 especially where it is a rocky or gravelly bed. Stag- 
 nant water, and that of marshes, is in general exceed- 
 ingly impure, and often offensive to the taste, as it is 
 largely impregnated with principles derived from the 
 putrefaction of animal and vegetable matters. All these 
 waters, however, possess the property called softness; 
 that is, they will dissolve soap. Spring waters are gene- 
 rally hard: they will not dissolve soap; and are, there- 
 fore, unfit for any domestic purposes, and for manufac- 
 turers. This arises from their containing earths and 
 minerals in solution. Springs which supply water of a 
 more agreeable taste than rain, river, or lake water, 
 are the most abundant ; and they always contain car- 
 bonic acid. Other impregnations impair their taste; 
 und, when they are in such access as to give a marked 
 character to the water, the waters of such springs are 
 called Mineral waters. 
 
 tt may often be important to obtain a general idea of
 
 MINERAL WATERS. 81 
 
 the impregnations of a particular spring, in order to know 
 whether it can be safely taken with food, or is likely tc 
 be useful as a medicine, or ought to be wholly rejected. 
 We shall therefore give a short account of the tests, by 
 which the most usual impregnations may be detected. 
 
 The sensible qualities of water, such as transparency, 
 colour, taste, and smell, should be examined, if possible, 
 at the instant it comes from the spring. If the water 
 must necessarily be examined at a distance, a bottle, 
 with an air-tight stopper, should, at the fountain-head, 
 be completely filled with it, in order to leave no space 
 for air. The specific gravity should also be taken. To 
 note exactly the sensible qualities of the water, will 
 often indicate the re-agents which may be employed to 
 denote its composition. 
 
 Spring water generally contains more or less carbonic 
 acid, which imparts an agreeable sparkling and brisk- 
 ness; like that exhibited by fermented liquors. Where 
 no colouring matter is present, the sparkling induces 
 us to suppose this water more transparent than other 
 waters. 
 
 Carbonic acid sinks the taste of every other ingredient 
 in waters ; and, therefore, such waters should not only 
 be tasted at the spring, but some time after they have 
 been exposed to the air, or after they have been boiled, 
 as the carbonic acid will then have escaped. The tinc- 
 ture of litmus will discover whether an acid is present 
 in water, and as the carbonic is the only acid which is 
 separated by exposure to the air, this exposure, if it 
 deprive the water of the power of reddening litmus- 
 paper or its solution, will show whether the acid is 
 the carbonic or not. 
 
 Water containing carbonic acid will hold a. consider- 
 able quantity of carbonate of lime in solution. Lime is 
 detected most effectually by oxalic acid, which separates 
 it from all its combinations, and forms with it an insolu- 
 ble precipitate, unless an excess of acid be present, foi 
 then the precipitate will be re-dissolved. It is, therefore 
 best to use the oxalate of ammonia or potass, in order 
 that the alkali may neutralize the acid in solution. 
 J F
 
 82 CHEMISTRY. 
 
 Diluted muriate of barytes will form a precipitate 
 with water containing sulphuric acid. The precipitate 
 is white, and insoluble in diluted muriatic acid. 
 
 The nitrate of silver occasions a white precipitate or 
 cloud in water containing muriatic acid. 
 
 Alkalies held in solution, or alkaline or earthy carbo 
 nates, change paper stained with turmeric to a brown, 
 or reddish brown, and light vegetable reds are rendered 
 blue. The volatile alkali may be distinguished by its 
 smell. Earthy and metallic carbonates are precipitated 
 by boiling. 
 
 Iron is very common in mineral wafers; it may be 
 detected by its forming a purple or blackish precipitate 
 with tincture of galls, or blue with prussiate of potass. 
 
 Pure ammonia, or lime-water, precipitates magnesia 
 and alumine, and no other earths, provided the carbonic 
 acid has previously been separated by a fixed alkali and 
 ooiling. 
 
 The mineral acids, when uncombined, give a perma- 
 nent red to litmus paper, both before and after the water 
 has been boiled ; whereas, the redness communicated by 
 the carbonic acid gas goes off as the paper dries. 
 
 Waters containing the sulphate of copper, may be de- 
 tected by their giving the colour of copper to a polished 
 plate of iron immersed in them. 
 
 Sulphate of iron is precipitated by alcohol. 
 
 The specific gravity of sea-water is generally 1.0280 
 It holds about ? V f i^ s weight of muriate of soda in so- 
 lution, with a small quantity of muriate of magnesia, ana 
 a still smaller proportion of the sulphate of lime. At a 
 distance from land, it is colourless and void of smell, but 
 intensely saline and bitter. 
 
 In analyzing waters with exactness, the gaseous pro 
 ducts they afford are carefully collected and examined. 
 
 OF THE AIR. 
 
 The atmosphere may be said in general terms to con- 
 sist of oxygen and nitrogen ; but atmospheric air, even
 
 THE AIR. 83 
 
 when purest, always contains a small proportion of other 
 principles. Murray states its exact composition as follows 
 
 
 
 By measure. By weight. 
 
 o p S 
 
 210 23 3 
 
 
 1 40 i no 
 
 queous vapour 
 
 
 
 
 
 100.0 100.0 
 
 As considerable quantities of hydrogen escape from 
 the earth, it might be presumed that it would be found 
 in the atmospheric air, but as the atmospheric air has 
 no chemical attraction for it in any proportion that can be 
 detected, it probably escapes, by its levity, beyond the 
 heights to which we have access. Dalton's experiments 
 evince that the proportion of carbonic acid gas does not 
 exceed a thousandth part, though a higher estimate is 
 generally made. 
 
 Atmospheric air is destitute of taste and smell, highly 
 compressible, and perfectly elastic. It supports animal 
 life, directly by the oxygen it affords to the lungs, where 
 the blood combines chemically with it; and indirectly, 
 by its mechanical properties in equalizing the tempera- 
 ture of. the globe, and preventing too rapid an evaporation 
 cf the moisture of the body. It is also not less necessary 
 to vegetable life, as the vehicle for the distribution of 
 water, and in its decompositions, by furnishing them with 
 nitrogen, carbonic acid, and other principles. 
 
 Atmospheric air contains the only proportion of oxy- 
 gen which is subservient to the purpcses of existence 
 all the known gases have been tried. None of them ex- 
 cept the nitric oxide, can be breathed for even a few 
 moments; and even the nitric oxide, during the short 
 time \vhi( h it remains on the lungs, produces a suspen- 
 sion of the proper functions of the mind. In all the 
 gases, also, combustion is either intemperate or wholly 
 stopped. Notwithstanding the multiplied compositions 
 and decompositions which are continually going on at
 
 84 CHEMISTRY. 
 
 the surface of the earth, the due proportion of oxygen 
 in the air is still maintained with a precision truly 
 astonishing. 
 
 The specific gravity of the air is less, the greater the 
 proper I ion of aqueous moisture which it contains. Hence, 
 aeronauts find that their balloon sinks when passing over 
 the sea, where the air is moister than over the land. 
 
 OF GAS. ' 
 
 THIS term is applied to all permanently elastic fluids, 
 simple or compound, except the atmosphere, to which 
 the term air is appropriated. 
 
 Some of the gases exist in nature without the aid of 
 art, and may, therefore, be collected ; others, on the con- 
 trary, are only producible by artificial means. 
 
 All gases are combinations of certain substances, re- 
 duced to the gaseous form by the addition of caloric. It 
 is, therefore, necessary to distinguish, in every gas, the 
 matter of heat which acted the part of a solvent, and 
 the substance which forms the basis of the gases. 
 
 Gases are not contained in those substances from 
 which we obtain them in a state of gas, but owe their 
 formation to the expansive property of caloric. 
 
 The formation of gases. The different forms under 
 which bodies appear, depend upon a certain quantity of 
 caloric, chemicarly combined with them. The very for- 
 mation of gases corroborates this truth. The production 
 totally depends upon the combinations of the particular 
 substances with caloric; and though called permanently 
 elastic, they are only so because we cannot so far reduce 
 their temperature, as to dispose them to part with it 
 otherwise they would undoubtedly become fluid or solid. 
 
 Water, for instance, is a solid substance in all degrees 
 below 32 of Fahrenheit's scale ; above this temperature 
 it combines with caloric, and it becomes a fluid. It 
 retains its liquid state under the ordinary pressure of the 
 Atmosphere, till its temperature is augmented to 212. 
 It then combines with a larger portion of caloric, and is
 
 ALCOHOL. 80 
 
 Converted, apparently, into gas, or at least into elastic 
 vapour ; in which state it would continue, if the tempe- 
 rature of our atmosphere was above 212. Gases are 
 therefore solid substances, between the particles of which 
 a repulsion is established by the quantity of caloric. 
 
 But as in the gaseous water or steam, the caloric is 
 retained but with little force, on account of its quitting 
 the water when Ihe vapour is merely exposed to a lowe! 
 temperature, we do not admit steam among the class of 
 gases, or permanently elastic aeriform fluids. In gases, 
 caloric is united by a very forcible affinity, and no dimi- 
 nution of temperature, or increase of pressure, that has 
 ever yet been effected, can separate it from them. Thus 
 the air of our atmosphere, in the most intense cold, or 
 when very strongly compressed, still remains in the aeri- 
 form state ; and hence is derived the essential characters 
 of gases, namely, that they shall remain aeriform, under 
 all variations of pressure and temperature. 
 
 OF ALCOHOL. 
 
 ALCOHOL, or the purely spiritous part of liquors which 
 Lave undergone the vinous fermentation, and no other, 
 is transparent. and colourless like water ; its taste is high- 
 ly pungent, but agreeable. It is extremely inflammable, 
 and when set on tire it leaves no residuum. Its specific 
 gravity is 0.800 ; and from its brightness and extreme 
 fluidity, the bubbles which are formed on its surface, 
 break with rapidity. It is not frozen even by the ex- 
 treme cold of 65 ; but it has been frozen by the sudden 
 abstraction of its caloric in the vacuum of an air-pump. 
 fn a vacuum, it boils at 56 ; in the air it is converted into 
 vapour at 55, and boils at 165. It is from its being 
 converted into vapour much sooner than water, that it 
 is easily separated by distillation from wine, beer, and 
 other liquors which contain it. All these liquors owe 
 their strength to the quantity of alcohol they contain : 
 the best port-wine contains about one-fourth of its bulk 
 of alcohol. Brandy, rum, and whiskey, contain still more 
 alcohol. Proof-spirit is half water and naif alcohol. 
 - 8
 
 86 CHEMISTRY. 
 
 The alcohol obtained by distillation always contains 
 some water, from which that operation will not free it; 
 to obtain pure alcohol, therefore, perfectly dry potass 
 obtained by exposing this alkali for some time to a red 
 heat, is put into it : the water, having a stronger affinity 
 for the potass than for the alcohol, combines with the 
 alkali, which falls to the bottom, and the alcohol may bo 
 drawn off with the siphon. Afterwards the alcohol should 
 be distilled with a gentle heat, and not quite to dryness, 
 that any potass it may contain may be left behind. 
 
 Alcohol mixes with water in all proportions, and the 
 combination is so intimate that the mixture takes up less 
 space than the fluids separately ; and therefore, as in 
 every other combination where such an effect happens, 
 caloric is extricated, and may be felt by the hand. 
 
 Alcohol is the grand solvent for resins, and is much 
 used for making varnishes. Camphor dissolves in it very 
 readily, and the solution hastens that of some substances 
 upon which the alcohol alone acts but slowly, or not at 
 all, particularly copal. 
 
 Alcohol takes up a small portion of phosphorus, which 
 is precipitated by water. Quicklime alters the flavour 
 of alcohol, and renders its colour yellow, though the 
 earth in general, and metallic oxides, appear to have no 
 action upon it. Both fixed and essential oils are soluble 
 in alcohol. 
 
 The composition of alcohol is not accurately known. 
 The analysis of Lavoisier indicated that 100 parts of it 
 contain of carbon, 30, of hydrogen, 7.5, and of water 
 62.5 : but the accuracy of the analysis is doubtful ; for, 
 as it was conducted by burning the alcohol in oxygen, 
 part of the water may have .been the produce of com- 
 bustion, as Fourcroy and Vauquelin have clearly proved 
 that alcohol contains oxygen. However this be, the 
 manner in which the component parts of alcohol are 
 united, remains entirely a mystery. 
 
 Betancourt has ascertained the important fact, tha< 
 the vapour of alcohol has more than double the expan- 
 sive force of that of water of the same temperature, and
 
 ETHER. 87 
 
 that <;he steam of alcohol, at 174, is equal to that of 
 water at 212. Hence, it has been suggested that alco- 
 hol may be employed with advantage as the moving 
 power of steam engines, with a great saving of fuel, and 
 consequently, of expense, when means shall be contrived 
 to save the fluid from being lost. 
 
 OF ETHER. 
 
 IF alcohol be mixed with its own weight of sulphuric 
 acid, gradually added, to prevent explosion, and the 
 mixture be distilled in a sand bath, the first product ob- 
 tained is alcohol, but afterwards a very different fluid, 
 which is equal in quantity to half the alcohol employed. 
 This fluid is called ether." 
 
 Ether is still more inflammable and volatile than alco- 
 hol, and equally as colourless. It is the lightest of all 
 known fluids. Its smell is fragrant and agreeable, but 
 not powerful. Its taste is hot and pungent. Its combus- 
 tion yields a blue flame, and rather more smoke than 
 alcohol. It boils at 95. It may be obtained of the spe- 
 cific gravity of .716. 
 
 It is a valuable medicine; being used externally for 
 the headache or toothache, by pouring a little upon the 
 hand and pressing it upon the forehead or cheek, till the 
 pain it occasions goes off Its internal use extends to all 
 spasmodic affections. 
 
 The nature of the change produced on alcohol by the 
 acid, when ether is formed, is not well understood ; but 
 it is supposed that ether contains a much larger propor- 
 tion of hydrogen in proportion to its carbon. 
 
 If the distillation of ether be continued till sulphurous 
 vapours appear, and the recipient be then changed, a 
 new product is obtained ; it is called the sweet oil of 
 wine, which is unctuous, thick, less volatile than ether, and 
 of a yellow colour. The last product obtained by urging 
 the fire, is sulphuric acid and acetous acid. 
 
 Instead of the sulphuric acid, ether may be prepared 
 c-'th the nitric, the oxymuriatic, the acetic, and several
 
 88, CHEMISTRY. 
 
 other acids. According to the acid employed, its proper 
 ties differ a little : nitric ether is often made, but the sul- 
 phuric is the most common and the most valued. The 
 peculiar properties of the ethers made with differen* 
 acids, have not been minutely examined. 
 
 Sulphuric ether acts upon most resinous substances; it 
 is the best solvent of caoutchouc ; it dissolves also the 
 essential oils and camphor; mixes in all proportions with 
 alcohol, but water only dissolves a tenth of it. It com 
 bines with caustic volatile alkali ; but not with the fixea 
 alkalies or lime. It dissolves a little sulphur and phos- 
 phorus. 
 
 If the ether obtained emit a sulphurous odour, it must 
 be purified by a second distillation, previous to which it 
 should be mixed with a little potass, which will combine 
 with the acid, and in part with the water. 
 
 OF METALS. 
 
 THE metals, from their extensive and diversified 
 utility, are amongst the most interesting classes of sub 
 stances existing. They are supposed to be simple bodies, 
 and not a single fact has ever been ascertained which 
 shows that they can be converted into each c^her; yet ; 
 to accomplish this, the alchemists exhausted their estates 
 and their lives. 
 
 The metals are distinguished by their possessing all or 
 the greater part of the following properties; hardness, 
 tenacity, lustre, opacity, fusibility, malleability, and duc- 
 tility ; and they are excellent conductors of caloric, elec- 
 tricity, and galvanism. 
 
 Metals are generally found in mountainous countries. 
 They are sometimes met with in a state of purity, 
 and are then said to be found native: but they are 
 mostly combined with other substances ; and, when com- 
 bined in such quantities as to be worth separating, the 
 substance is called an ore of the metal it contains. 
 
 All the metals are susceptible of crystallization. The 
 easiest mode of obtaining their crystalline form, is to lei
 
 METALS. 89 
 
 out the middle part just after they have begun to con 
 geal ; the interior of the crust thus left assumes a crys- 
 talline form. 
 
 The metals are fusible at very different temperatures; 
 mercury, for example, does not become solid, unless 
 cooled down to 39, and platina is not softened at the 
 heat at which cast-iron runs like water. 
 
 Metals differ from each other as much in hardness as 
 in fusibility. Kirwan has adopted a very simple mode 
 'of showing their comparative hardness by figures. We 
 shall adopt his plan, which he thus explains: 
 
 3. Denotes the hardness of chalk. 
 
 4. A superior hardness ; but yet what yields to the 
 nail. 
 
 5. What will not yield to the nail; but easily, and 
 without grittiness, to the knife. 
 
 6. That which yields with more difficulty to the knife. 
 
 7. That which scarcely yields to the knife. 
 
 8. That which cannot be scraped by a knife, but does 
 not give 'fire with steel. 
 
 9. That which gives a few feeble sparks with steel. 
 
 10. That which gives plentiful, lively sparks. 
 
 Great specific gravity was formerly considered as one 
 of the chief characteristics of the metals, the lightest 
 metal being twice as heavy as the heaviest body of any 
 other sort; but the discovery of several bodies, which 
 possess all the characters of the metals, excepting weight, 
 and which cannot therefore be omitted in the list of 
 metals, has caused great specific gravity to be no longer 
 distinctive. 
 
 If a metal be exposed to a heat which will keep it in 
 fusion, it may, without suffering any alteration but that 
 of its figure, (which will adapt itself to the vessel,) be 
 kept any length of time in that state, provided the access 
 of air be kept entirely from its surface. But if the fusion 
 be conducted in open vessels, the surface of the metal 
 loses its metallic brilliancy ; and if its apparent scum be 
 removed, another is soon formed, until the whole of the 
 metal disappears, and instead of it we have an eartjiy 
 8*
 
 90 CHEMISTRY. 
 
 opaque powder which soils the hands. Upon collecting 
 and weighing this powder, it is found to be heavier than 
 the metal from which it was produced. This process 
 was by the ancient chemists called calcination, and the 
 product of it was called a calx ; they knew not the 
 cause of it, and were, therefore, wholly unable to account 
 for the increase of weight which they obtained by it; 
 but the moderns having thoroughly investigated the sub- 
 ject, consider all metals as combustible bodies; that in 
 the operation just described the metal has suffered com- 
 bustion, and that, therefore, the oxygen of the atmos- 
 phere has combined with it, as it combines with all other 
 bodies during combustion, and that it is solely from the 
 oxygen absorbed that its additional weight is derived. In 
 proof of this, they find by suitable experiments, that the 
 oxygen absorbed is exactly equal to the weight acquired ; 
 and also, that when the oxygen is taken away, by pre- 
 senting some substance for which it has a greater affinity, 
 the metal acquires all its original properties, and becomes 
 of the same weight as at first. Hence for the vague 
 term calx, the modern chemists used the word oxide, to 
 denote the earth-like combinations of a metal with 
 oxygen ; and the act or process in which this change 
 takes place, is called oxidation, 
 
 Oxygen will not combine with metals in all propor 
 lions, as acids will do with water, but only in one or two, 
 or at most a few proportions. When the proportion 
 of oxygen varies, the oxide of the same metal assumes 
 different colours ; the colour is therefore selected to dis- 
 tinguish these differences. Hence, we have the yellow 
 oxide of lead, the red oxide of lead, &c. When the 
 oxygen which converts a metal into an oxide is supplied 
 by an acid, the name of the solvent, as well as the colour 
 of the oxide, is sometimes given : thus we have the white, 
 oxide of lead by the acetous acid. 
 
 Some of the metals are so much disposed to oxidation, 
 that they became oxides at all temperatures. Iron is a 
 metal )f this description : the rust to which it changes in 
 air or water is its red oxide.
 
 METALS. 91 
 
 If the oxide of a metal be exposed to a strong heat, it 
 nitrifies, or is converted into a substance resembling com- 
 mon glass. The substances employed for enamel paint- 
 ing, for colouring glass, and for glazing earthenware, are 
 mostly prepared from metallic oxides. 
 
 If any of the malleable metals be hammered, its com- 
 bined caloric becoming sensible, renders it hot, and 
 passes off to surrounding bodies ; the metal at the same 
 time is rendered denser, harder, more rigid, and in gene 
 ral more elastic. A portion of the caloric, to which, in 
 common with other bodies, metals owe their softness, 
 appears to be driven out of it; for its former state re- 
 turns by beating it to ignition. Rolling produces the 
 same effect as hammering. 
 
 The metals combine with each other, and besides 
 oxygen, w;*h the simple substances, sulphur, carbon, and 
 phosphorus When two metals are combined together, 
 the mixture is called an alloy of that metal whose weight 
 predominates. 
 
 Previous to the year 1730, only eleven metals were 
 known the list is now increased to forty-two chiefly by 
 recen* discoveries, and the probability is very strong, that 
 there exist : a much larger number. The metals may be 
 divided in' \ two classes; the malleable and the brittle; 
 the brittle metals may be further subdivided into those 
 which ar easily fused, and those which are fused with 
 difficulty. We shall enumerate them, in each of these 
 classes, in ihe order of their specific gravity. 
 
 1. Malleable Metals. 
 
 1. PVxtina, 8. Copper, 
 
 2. Gold, 9. Iron, 
 
 3. Mercury, 10. Tin, 
 
 4. Lead, 11. Zinc, 
 
 5. Palladium, 12. Sodium, 
 
 6. Silver, 13. Potassium. 
 
 7. Nickel, 
 
 2. Brittle Metals, fused without difficulty. 
 
 1. Bismuth, 3 Antimony, 
 
 2. Arsenir,, 4. Tel'-'-'num.
 
 92 CHEMISTRY. 
 
 Brittle Metals, of difficult fusion. 
 
 1. Tungsten, 8. Titanium, 
 
 2. Uranium, 9. Chromium, 
 
 3. Rhodium, 10. Columbium, 
 
 4. Cobalt, 11. Cerium, 
 
 5. Molybdenum, 12. Osmium, 
 
 6. Manganese, 13. Iridium 
 
 7. Tantalium, 
 
 PLATINA. 
 
 THE specific gravity of platina, after hammering, is 
 23,000. It, therefore, holds the pre-eminence of all 
 bodies in point of weight, and it has other extraordinary 
 properties. 
 
 It is incapable of tarnishing by exposure to the air 
 The strongest mineral acids have no effect upon it, if 
 employed separately, nor will the strongest fire melt it, 
 unless urged by oxygen gas ; a crucible of it not thicker 
 than a sheet of paper, will endure the heat of the best 
 furnace, and come out unaltered. When intensely heat- 
 ed, it possesses, like iron, the property of welding, but 
 the labour of working it is very great. Its hardness is 
 7.5. Its colour is between that of iron and silver. 
 
 Platina was unknown in Europe before the year 1741, 
 when a quantity of it was brought by Charles Wood, 
 from Jamaica. It was supposed only to be found in the 
 gold mines in Peru, but Vauquelin has met with it in 
 Spain, in the mines of Guadalcanal. Its name, in the 
 language of Peru, signifies little silver, and on its great 
 specific gravity being ascertained, attempts have been 
 made to prevent its use, lest gold should be adulterated 
 with it. It has never been met with except in the 
 metallic state, in the form of smooth grains of all sizes 
 up to that of a pea, but very seldom larger. 
 
 Platina may be fused by a powerful burning-glass ; 
 but its- total infusibility by ordinary means, has caused 
 various processes to be resorted to, for obtaining it in a 
 solid, malleable state. For this purpose it must be dissol
 
 PLATINA. 93 
 
 / / in an acid ; oxymuriatic acid, and nitre-muriatic acid 
 6\ fti dissolve it. The latter acid should consist of one 
 part of nitric, and three of muriatic acid. The solution 
 is very corrosive, and tinges animal substances of a black- 
 ish brown colour ; it affords crystals by evaporation 
 Count Moussin Pouschin directs malleable platina to be 
 prepared from its solution as follows: Precipitate the 
 platina by adding a solution of muriate of ammonia, and 
 wash the precipitate with a little cold water. It is 
 red-coloured, which distinguishes this metal from gold. 
 Reduce it in a convenient crucible to the well-known 
 spongy metallic texture, wash the mass obtained two or 
 three times in boiling water, to carry off any portion ot 
 saline matter that may have escaped the action of the 
 fire. Boil it in a glass vessel for about half an hour, in 
 as much water mixed with one-tenth of muriatic acid, 
 as will cover it about half an inch. This will carry off 
 the iron that might exist in the metal. Decant the acid 
 water, and edulcorate or strongly ignite the platina. To 
 one part of this metal take two parts of mercury, and 
 amalgamate in a glass or porphyry mortar. This amal- 
 gamation takes place very readily. The proper method 
 of conducting it, is to take about two drachms of mercury 
 to three of platina, and amalgamate them together, and 
 to this amalgam may be. added alternate small quantities 
 of platina and mercury, till the whole of the two metals 
 is combined. Several pounds may thus be amalgamated 
 in a few hours, and in the large way, a mill might short- 
 en the operation. As soon as the amalgam of mercury 
 is made, compress it in tubes of wood, by the pressure of 
 an iron screw upon a cylinder of wood adapted to the 
 bore of the tube. This forces the superabundant mer- 
 cury from the amalgam, and renders it solid. After two 
 or three hours, burn upon the coals, or in a crucible lined 
 with charcoal, the sheath, in which the amalgam is con- 
 tained, and urge the tire to a white heat; after which 
 the platina may be taken out in a very solid state, tit to 
 be forged. 
 
 The ductility of platina is such, that it has been drawn
 
 94 CHEMISTRY. 
 
 into wire of less than the two-thousandth part of an inch 
 in diameter. This wire admits of being flattened, and 
 is stronger than that of gold or silver, of the same thick- 
 ness. 
 
 Platina will not comhine with gold, except in a violent 
 heat. When not more than one forty-seventh of the al- 
 loy is platina, the gold is not perceptibly altered in colour; 
 but, if the proportion be materially greater, the paleness 
 of the gold betrays its impurity. Added in the proportion 
 of one-twelfth to gold, it forms a yellowish-white metal, 
 highly ductile, and so elastic, that Hatchett supposed it 
 might be used for watch-springs, and other purposes. Its 
 specitic gravity was 19.013. 
 
 It also requires a violent heat to make platina and 
 silver combine: the silver becomes less white and duc- 
 tile, but harder. If the two metals be kept for some 
 time in fusion, they separate, and the platina, from ifc 
 greater weight, sinks to the bottom. 
 
 The alloy of copper and platina is hard, yet ductile, 
 while the copper is in proportion of three or four parts 
 to one. This alloy is not liable to tarnish, especially 
 when the platina predominates ; and it is, therefore, ex- 
 cellent for the specula of reflecting telescopes, as platina 
 takes an excellent polish, and reflects a single image. 
 The addition of a little arsenic improves this alloy. But 
 copper is much improved in colour, grain, and suscepti- 
 bility of polish, when the platina is only in proportion of 
 a tenth or fifteenth. 
 
 Alloys of platina with tin or lead are very apt to tar- 
 nish ; that with lead is formed at the strongest heat : i 
 is not ductile, and the lead is not absorbed by the cupel 
 unless it is in excess ; and even then, the separation of 
 (he lead is not complete. 
 
 Platina unites easily with tin ; the alloy is very fusi- 
 ble, but its grain is coarse and brittle. It is ductile, 
 when the proportion of tin is large : it becomes yellow 
 by exposure to the air. 
 
 Zinc renders platina more fusible, and forms with it a 
 very hard alloy The zinc cannot be entirely separated 
 bv heat
 
 METALS. 05 
 
 Bismuth and antimony likewise facilitate the fusion 
 Df platina, with which they form brittle alloys, and are 
 not wholly separated by heat. Arsenic has the same 
 effect as these metals in promoting its fusion. 
 
 Platina has not been united to forced iron ; but with 
 cast iron, it forms an alloy which resists the file. % 
 
 If phosphorus be thrown upon red-hot platina, the 
 metal is fused, and forms a phosphuret, which is of a 
 silvery white, very brittle, and hard enough to strike 
 fire with steel. As heat expels the phosphorus, Pollitier 
 proposed this as an easy method of purifying platina ; 
 but he afterwards found that the last portions of phos- 
 phorus were retained by too strong an affinity. 
 
 Several of the metallic salts decompose the solution 
 of muriate of platina. Muriate of tin is so delicate a. 
 test of it, that a single drop, recently prepared, gives a 
 bright red colour to muriate of platina, which before 
 this addition, is so clear as to be scarcely distinguished 
 from water. 
 
 If nitro-muriatic solution of platina be precipitated by 
 lime, and the precipitate digested in sulphuric acid, a sul- 
 phate of platina will be formed. A sub-nitrate may be 
 for med in the same way. 
 
 Platina does not form a direct combination with sul 
 phur, but is soluble by the alkaline sulphurets, and pre- 
 cipitated from its nitro-muriatic solution by sulphuretted 
 hydrogen. 
 
 The fixedness of platina admirably fits it for crucibles, 
 and many other chemical utensils, which may be made 
 thinner of this than of any other material whatever. 
 It is, however, besides the disadvantages of its expense, 
 liable to corrosion from caustic alkalies, and some of the 
 neutral salts. 
 
 If either be mixed and agitated with the nitro-muri- 
 atic solution of platina, it takes up the metal; and, as it 
 will soon float on the surface of the solution, it may be 
 poured ofF, and, if brushed over the clean surface of any 
 other metal, it will soon evaporate, and impart to them 
 a coating of platina.
 
 96 CHEMISTRY. 
 
 GOLD. 
 
 GOLD is the most malleable, ductile, and most brilliant 
 of all the metallic substances ; and, next to platina, the 
 heaviest and most indestructible. 
 
 (jold is seldom found except in the metallic state. It 
 has been obtained in every quarter, and almost every 
 country of the globe; but South America supplies a 
 greater quantity than all the rest of the world. 
 
 Many laborious experiments have been repeatedly 
 made by able chemists, who appear to have established 
 the fact, that gold exists in vegetables. 
 
 A single grain of gold can be made to cover an area 
 of more than 400 square inches; a wire of one-tenth of 
 an inch in diameter will support a weight of 500 pounds ; 
 and Dr. Black has calculated that it would take fourteen 
 millions of films of gold, such as cover some fine gilt 
 wire, to make up the thickness of an inch ; whereas the 
 same number of leaves of common writing paper would 
 make up nearly three quarters of a mile. 
 
 Though opacity is enumerated as one of the charac- 
 ters of the metals, yet gold, when the oTaVo^th of an 
 inch thick, which is about the thickness of ordinary gold 
 leaf, transmits light of a lively bluish green colour. Per- 
 haps all the other metals, if they could be equally 
 extended, would show some degree of transparency, but 
 none of them can be "made so thin. 
 
 The specific gravity of unharnmered gold, is 19.258, 
 and is increased but little by hammering. Its hardness 
 is 6. It melts at 32, of Wedgwood ; and if pure, its 
 colour when in fusion is not yellow, but a beautiful 
 bluish green, like the light which it transmits. 
 
 Gold cannot be volatilized, except at an extreme heat. 
 The utmost power of Parker's celebrated burning lens 
 exerted upon it for some hours, did not cause it to lose 
 any weight which could be discovered; but Lavoisier 
 found that a piece of silver, held over gold melted by a 
 fire maintained with oxygen gas, was sensibly gilt : and 
 perhaps the same delicate test would have shown its 
 volatility by the lens.
 
 GOLD. 97 
 
 After fusion, gold will assume the crystalline form. 
 Tillet and Mongez obtained it in short quadrangular 
 pyramidal crystals. 
 
 Gold unites with most of the metals. Silver renders 
 it pale ; when the proportion of silver is about one-fifth 
 part, the alloy has a greenish hue. Silver separates 
 from gold as from platina, if the alloy be kept for some 
 time in fusion. 
 
 Gold is strongly disposed to unite with mercury ; this 
 alloy forms an amalgam, the softness of which is in pro- 
 portion to the quantity of mercury. It is by mercury, 
 that in South America, gold is chiefly obtained from the 
 earth with which it is mixed, and the gold is -separated 
 *>y distillation. This alloy readily crystallizes after fusion. 
 It is applied by gilders to the surface of clean copper, 
 and the mercury is driven off by heat 
 
 Gold unites freely with tin and lead, but both these 
 metals impair its ductility. Of lead, one quarter of a 
 grain to the ounce renders the gold brittle ; but tin has 
 not so remarkable an effect. 
 
 Copper increases the fusibility of gold, as well as its 
 hardness, and deepens its colour. It forms the usual 
 Addition to gold for coin, plate, &c. The standard gold 
 of Great Britain is twenty-two parts pure gold, and two 
 parts copper ; it is, therefore, called " gold of twenty- 
 two carats fire." 
 
 Iron forms an alloy with gold, so hard as to be fit for 
 edge tools. Its colour is grey, and it obeys the magnet. 
 
 Arsenic, bismuth, nickel, manganese, zinc, and anti- 
 mony, render gold white and brittle. When the alloy is 
 with zinc in equal proportions, it has a fine grain, takes 
 a high polish, and from these qualities, and its being not 
 liable to tarnish, it forms a composition not unsuitable for 
 the mirrors of telescopes. 
 
 For the purpose of coin, Hatchett considers an alloy 
 consisting of equal parts of silver and copper as the best, 
 and copper alone as preferable to silver. The same dis- 
 tinguished chemist gives the following order of different 
 metals, arranged as thev diminish the ductility of gold: 
 U G
 
 98 CHEMISTRY. 
 
 viz. Bismuth, lead, antimony, arser'c, zinc, cobalt, mangh 
 nese, nickel, tin, iron, platina, copper, silver. The first 
 three were nearly equal in effect, but the platina wa$ 
 not quite pure. 
 
 The nitric acid will take up a very minute quantity 
 of gold, but the nitro-muriatic and oxy-muriatic acids 
 are its only real solvents. The two latter acids are of a 
 similar nature, and their effects on gold are increased by 
 concentrating them, by enlarging the surface of the gold 
 and by the application of heat. The solution is of a 
 yellow colour, caustic, and tinges the skin of a deep pur- 
 ple. By evaporation it affords yellow crystals, which 
 take the form of truncated octahedrons. These crystals 
 are a muriate of gold ; they may be dissolved in water, 
 and will stain the skin in the same manner as the acid. 
 
 Most metallic substances precipitate gold from its solu- 
 tion in the nitromuriatic acid : lead, iron, and silver, 
 precipitate it of a deep and dull purple colour ; copper 
 and iron throw it down in its metallic state ; bismuth, 
 zinc, and mercury, likewise precipitate it. When pre- 
 cipitated by tin, it forms the purple precipitate of Cassius, 
 which is much used by enamellers and manufacturers 01 
 porcelain. 
 
 Ether, naphtha, and essential oils, take gold from its 
 solvent, and from liquors which have been called potable 
 gold, and are used in gilding. The gold obtained from 
 these fluids by evaporation, is extremely pure. 
 
 If diluted nitromuriatic solution of gold be used to 
 write with upon any substance, and the letters while yet 
 moist, be afterwards exposed to a stream of hydrogen gas, 
 the gold will be revived, and the substance will appear 
 gilt. Ribbons may be gilt in this manner. Sulphurous 
 acid gas revives the gold in the same manner. 
 
 Lime and magnesia precipitate gold from its solution 
 in the form of a yellowish powder. Alkalies do the same, 
 but an excess of ilkali re-dissolves the precipitate. The 
 precipitate obtained by means of a fixed alkali appears 
 to be a true oxide ; it is taken up by the sulphuric, nitric, 
 anrf muriatu cids, but separates by standing with crys-
 
 GOLD. 99 
 
 tallizing. The precipitate by gallic acid is of a reddish 
 colour, and very soluble in the nitric acid, to which it 
 communicates a blue colour. 
 
 Gold precipitated from its yellow solution by ammoniac, 
 forms a powder called fulminating gold; this dangerous 
 compound detonates by friction, or a very gentle heat. 
 It cannot be prepared or preserved without great risk. 
 Macquer gives an instance of a person who lost both 
 eyes by the bursting of a bottle containing some of it ; 
 and which exploded by the friction of the glass-stopper 
 against an unobserved grain of it in the neck of the 
 bottle. 
 
 Green sulphate of iron precipitates gold of a brown 
 colour; but this soon changes to the colour of gold. 
 
 The alkaline sulphurets precipitate gold from its solu- 
 tion ; the alkali unites with the acid, and the gold falls 
 down combined with the sulphur. The sulphur may be 
 expelled by heat. 
 
 The alkaline sulphurets will also dissolve gold. Thus, 
 if equal parts of sulphur and potass, with one-eighth of 
 their joint weight of gold in leaves, be fused together, 
 the mixture, when poured out and pulverized, will dis- 
 solve in hot water, to which it gives a yellowish green 
 hue. Stahl wrote a dissertation to prove that Moses 
 dissolved the golden calf in this manner. 
 
 Sulphur alone has no effect on gold. The process 
 Called dry-parting is founded upon this circumstance. 
 This is used for separating a small quantity of gold from 
 a large quantity of silver. The alloy is fused, and flow- 
 ers of sulphur are thrown upon its surface ; the sulphur 
 reduces the greater part of the silver to a black scoria. 
 The small remainder of the silver may now be separated 
 by solution in nitric acid. The advantage of the opera- 
 tion consists in saving the large quantity of nitric acid 
 which would have been required to dissolve the silver of 
 the alloy in its original state. 
 
 The heat produced by the electro-galvanic discharge 
 reduces gold to the state of a purple oxide.
 
 100 CHEMISTRY. 
 
 MERCURY. 
 
 MERCURY is distinguished from all other metals, by its 
 fluidity at the common temperature of the atmosphere. 
 Its colour is white, and its surface is like that of polished 
 silver. Its specidc gravity is 13.580; and it is, there- 
 fore, the heaviest of all substances, except platina and 
 gold. 
 
 Mercury boils at 655; and does not cease to be a 
 fluid, unless at or below the temperature of 39. In 
 Russia, and Hudson's Bay, this temperature sometimes 
 occurs naturally; it may, however, be obtained by a 
 freezing mixture. Mercury has then been examined, 
 and found to be perfectly malleable, working like soft 
 tin. Experiments with artificial cold afford but few op- 
 portunities for exhibiting this property ; but at Hudson's 
 Bay, where surrounding objects were all equally cold, 
 frozen mercury has been beaten upon an anvil into sheets 
 as thin as paper. A mass of it, being thrown into a 
 glass of warm water, became fluid, but the water was 
 immediately frozen, and the glass shivered to pieces. 
 To the touch, frozen mercury excites the same sensation 
 as "red-hot iron. 
 
 Mercury is frequently obtained from the mines in the 
 pure metallic state; sometimes it is combined with silver, 
 but mostly with sulphur, in combination with which it 
 is called cinnabar, when the mixture is of a red colour, 
 but Ethiop's mineral, when it is black. These are both 
 sulphurets of mercury. Mercury is supplied by many 
 countries. The mines of Idria, in the circle of lower 
 Austria, have been wrought for 300 years, and are esti- 
 mated to yield 100 tons annually. From Spain, which 
 supplies large quantities, it is exported to South America 
 for amalgamating with gold ; for which use, the consump- 
 tion is so prodigious, that the mine of Guanca Velica, 
 in Peru, does not supply enough. This mine is a vast 
 cavern, 170 fathoms in circumference, and 480 fathoms 
 deep. 
 
 Cinnabar, to obtain the metal from it, is mixed wit'i
 
 MERCURY. 101 
 
 qui(,k-lime, and then submitted to heat. The lime com- 
 bines with the sulphur, and the mercury which sublime? 
 from the mixture is collected in receivers. Mercury sub- 
 limes at the heat of 000, and then has the appearance 
 of a white smoke. In this state of vapour, its elasticity 
 renders it capable of bursting the strongest vessels, if the 
 attempt be made to resist its expansion. Distillation is 
 the ordinary means of purifying mercury. 
 
 Mercury combines very freely with gold, silver, lead, 
 tin, bismuth, and zinc ; not so freely with copper, arse- 
 nic, and antimony ; for iron, its affinity is extremely 
 slight, and less so still, if possible, for platina. 
 
 The alloy of mercury with any metal, if the mercury 
 predominates so far as to render it soft, and of the con- 
 sistence of butter, is called an amalgam. These amal- 
 gams are much employed in silvering and gilding, as the 
 mercury is easily driven off by heat, and the fixed metal 
 is left behind. The metal with which the backs of 
 looking-glasses are coated, is an amalgam of tin and 
 mercury. 
 
 The number of metals with which mercury combines, 
 renders it extremely liable to adulteration. The union 
 is in some cases so strong, that the baser metal will rise 
 along with it in distillation. The experienced eye can, 
 however, determine very small adulterations, by the want 
 of perfect fluidity and brightness. Impure mercury alsc 
 soils white paper, and the presence of lead may be 
 detected by agitating the metal with water, by which 
 means it will be oxidized. Or a very minute quantity 
 of lead, present in a large quantity of mercury, may be 
 detected by solution in nitric acid^ and the addition of 
 sulphuretted water. A dark brown precipitate will 
 ensue, and will subside in the course of a few days. One 
 part of lead may be thus separated from 15,263 parts of 
 mercury. Bismuth is detected by pouring a nitric solu- 
 tion, prepared without heat, into distilled water; this 
 metal will be separated in the form of a white precipi- 
 tate. If tin be present, a weak solution of muriate of 
 gold will cause a purple precipitate. 
 9*
 
 102 CHEMISTRY. 
 
 By agitating mercury for some time in oxygen 01 
 atmospheric air, a part of it is converted into a blac* 
 oxide. 
 
 Most of the acids have more or less action on mercury 
 The sulphuric acid requires the assistance of heat, and 
 sulphurous acid gas is disengaged during its action, and 
 a white oxide is formed, which becomes yellow by pour- 
 ing hot water upon it, and is then called turbith mineral ; 
 it is a subsulphate of mercury ; the water holds in solu- 
 tion sulphate of mercury. 
 
 The nitric acid dissolves mercury rapidly without heat ; 
 nitrous gas is disengaged, and the colour of the acid at 
 the same time becomes green. If the acid be strong, it 
 will take up its own weight of mercury in the cold, and 
 will bear dilution ; heat will enable the acid to dissolve 
 much more of the metal, and the addition of distilled 
 water will form a precipitate, which is yellow if the 
 water be hot, and white if it be cold. This, from its 
 resemblance to the turbith mineral mentioned above, is 
 called nitrous turbith. 
 
 All the combinations of mercury with nitric acid are 
 strongly caustic, and form a deep black or purple spot on 
 the skin. When nitrate of mercury is exposed to a 
 gradual and long continued low heat, it gives out a por- 
 tion of nitric acid, and is converted into a bright red 
 oxide ; this oxide retains a small portion of nitric acid ; 
 it is called red precipitate, which is employed in medi- 
 cine as a caustic. This red oxide parts with its oxygen 
 simply by heat, and the mercury recovers its metallic 
 state. The finest precipitate is made, by distilling the 
 mercurial solution till no more vapour arises ; then add- 
 ing several successive portions of acid, and distilling it 
 dry after each addition. The precipitate will thus be 
 obtained in small crystals of a superb red colour. Red 
 precipitate may be prepared by heat only: the mercury 
 must for this purpose be kept at the heat of about G00 
 for several months ; the red oxide thus formed was called 
 precipitate per se. 
 
 The acids, the alkalies, the earths, and most of the
 
 MERCURY. 10? 
 
 metals, precipitate mercury from its, olution in the nitric 
 acid. The precipitates by alkalies have the property of 
 exploding, if triturated with one-sixth of their weight oi 
 flowers of sulphur, and afterwards gradually heated. 
 
 The muriatic acid does not act on mercury, except by 
 long digestion, which enables it to oxidize a part, and it 
 dissolves the oxide. This acid, however, completely dis- 
 solves the mercurial oxides, which, when nearly in the 
 metallic state, or containing but little oxygen, form the 
 muriate of mercury. When the oxy-muriatic acid is 
 employed, the oxy-muriate of mercury, or corrosive sub- 
 imate, is formed. Corrosive sublimate is highly caustic 
 and poisonous. 
 
 Sulphur readily combines with mercury. If triturated 
 with this metal in a mortar, it forms with it a black sul- 
 phuret, formerly called ethiop's mineral. This compound 
 may also be formed by adding to sulphur in fusion one 
 foui th of its weight of mercury. 
 
 If ethiops mineral, or black sulphuret of mercury, be 
 sublimed, it affords the red sulphuretted oxide, or artificial 
 cinnabar. This cinnabar, when pounded and washed 
 for painters' use, is called vermilion. To prepare it with 
 accuracy, let 300 grains of mercury and 68 of sulphur, 
 with a few drops of solution of potass to moisten them, 
 be triturated in a porcelain mortar, with a glass pestle, 
 till converted to the state of black oxide. Add to this 
 100 grains of potass, dissolved in as much water. Heat 
 the vessel containing the ingredients over the flame of 
 a candle, and continue the trituration without inter- 
 ruption during the heating. In proportion as the liquid 
 evaporates, add clear water from time to time, so that 
 the oxide may be constantly covered to the depth of 
 near an inch. The trituration must be continued about 
 two hours; at the end of which time the mixture begins 
 to change from its original black colour to a brown, which 
 usually happens when a large part of the fluid is evapo- 
 rated. It then passes very rapidly to a red. No more 
 water is then to be added., but the trituration is to be con- 
 tinued without interruption. When the mass has acquired
 
 104 CHEMISTRY. 
 
 the consistence of a jelly, the red colour increases in 
 brightness with surprising rapidity. The instant (he 
 colour has acquired its utmost beauty, the heat must be 
 withdrawn, otherwise the red passes to a dirty brown. 
 This is KirchofPs method of preparing vermilion. Count 
 Moussin Pouschin discovered that the brown colour may 
 be prevented by taking the sulphuret from the fire as 
 soon as it begins to be red, and placing it in a gentle heat, 
 taking care to add a few drops of water, and to agitate 
 the mixture from time to time. By this treatment an 
 excellent red is obtained. 
 
 Phosphorus, mixed with red oxide of mercury, and 
 distilled, forms a phosphuret of mercury, which is of o 
 black colour, and in the air exhales phosphoric vapour. 
 
 PALLADIUM. 
 
 PALLADIUM is of a greyish white colour, scarcely dis- 
 tinguishable from platuia^and takes a good polish. It is 
 ductile, and very malleable ; flexible, when reduced to 
 thin slips, but not very elastic. Its fracture is fibrous, 
 and in diverging striae, showing a kind of crystalline ar- 
 rangement. It is harder than wrought iron. Its specific 
 gravity is about 10.9, but may be increased by hammer- 
 ing and rolling to 11.8. It is a less perfect conductor oi 
 caloric than the other metals, and less expansible, though 
 in this respect it exceeds platina. 
 
 Palladium was discovered by Dr. Wollaston in native 
 platina. When exposed to a strong heat, its surface tar- 
 nishes a little, and becomes blue ; but by increasing the 
 heat, it becomes bright. By an intense heat, it is fused, 
 but not oxidized. Its oxides, formed by means of acids, 
 may be reduced by heat alone. 
 
 Palladium may be obtained by adding to nitro-muri- 
 atic solution of crude platina, a solution of prussiate of 
 mercury, on which a flaky precipitate will gradually be 
 formed, of a yellowish white colour. This is prussiate 
 of palladium, from which the acid may be expelled bj 
 beat.
 
 PALLADIUM. 105 
 
 The sulphuric, the nitric, and the muriatic acids dis- 
 solve a small portion of palladium, and acquire by it a 
 red colour. The nitro-muriatic dissolves it rapidly, and 
 acquires a deep red. 
 
 Alkalies and earths precipitate palladium from its so- 
 lutions, generally of a fine orange colour ; an excess of 
 alkali partly re-dissolves the precipitate. 
 
 Alkalies act upon metallic palladium ; and this action 
 is assisted by the contact of air. 
 
 Green sulphate of iron precipitates palladium in a me- 
 tallic state; and all the metals, except gold, silver, and 
 platina, do the same. Prussiate of mercury produces a 
 yellowish white precipitate ; and, as it does not precipi- 
 tate platina, it is an excellent te^t of palladium. 
 
 Palladium forms with gold a grey alloy, harder than 
 gold, less ductile than platina, and of a coarse-grained 
 fracture. 
 
 With an equal weight of platina, it resembles platina 
 in colour and hardness; but it is not so malleable, and 
 melts at a heat a little higher than is requisite to fuse 
 the palladium. The specific gravity of this alloy Ls 
 15.141. 
 
 With an equal weight of silver, the alloy is harder 
 than silver, but softer than wrought-iron, and its polished 
 surface resembles platina, except that it is rather whiter; 
 specific gravity 1.29. 
 
 Equal parts of palladium and copper, are a little more 
 yellow, break more readily, assume somewhat of a lead- 
 en hue when filed, and are harder than wrought iron. 
 Specific gravity 10.392. 
 
 Lead increases the fusibility of palladium, and forms 
 with it an alloy of a grey colour, fine-grained fracture, 
 harder than any of the preceding alloys, but verv brittle 
 
 With tin, bismuth, iron, and arsenic, palladium forms 
 brittle alloys : that with bismuth is very hard.
 
 106 CHEMISTRY. 
 
 LEAD. 
 
 THE colour of lead is a bluish white ; its specific 
 gravity is 11.352 ; its hardness is 5 ; it is the softest, the 
 least elastic and sonorous, of all rnetals used in the arts 
 It melts before ignition. It has scarcely any taste, but 
 friction causes it to emit a peculiar smell. It stains paper 
 and the fingers of a bluish black. 
 
 Lead is very malleable, and therefore easily reduced 
 to thin plates by the hammer; but hammering neither 
 increases its specific gravity or hardness. Its ductility 
 'is not great ; a wire one- tenth of an inch in diameter 
 will support only 29|- pounds. 
 
 It is not certainly known that lead has ever been 
 found in the metallic state; the only lead ore that is ex- 
 tensively found and worked, is a sulphuret of lead ; it is 
 called galena, and is generally found in veins, both in 
 siliceous and calcareous rocks. Lead ore frequently con- 
 tains silver, and often antimony and bismuth. 
 
 To obtain lead from galena, the galena is pulverized, 
 and separated by washing from earthy admixtures; it is 
 then roasted in a reverberating furnace, and afterwards 
 melted in contact with charcoal. When the lead con- 
 tains a quantity of silver worth extracting, it is fused 5i; 
 a strong fire, and the wind from a pair of bellows being 
 directed over its surface, the whole of it is in succession 
 converted into a yellow scaly substance called litharge, 
 which being driven off as it forms, the silver is left at the 
 bottom of the crucible. The litharge is a sub-carbonate 
 of lead, and by fusing it with charcoal the lead is revived. 
 
 When lead is fused in an open vessel, its surface 
 quickly loses its lustre, and a scum appears, which is 
 soon converted into a darkish grey powder. In the heat 
 usually employed to melt lead, this grey powder or ox- 
 ide sustains no further alteration ; but, if spread upon a 
 suitable surface, and exposed to a low red heat, it be- 
 comes successively whitish, yellow, and lastly, of a bright 
 orange red. The yellow oxide is called by painters 
 masticot ; the red they call minium, or merely red lead
 
 LEAD. 10*7 
 
 If the heat be urged much further, red lead is converted 
 into litharge, which is a semi-vitreous su bstance ; that, by 
 a little further heat, becomes a complete yellow glass, 
 of so fusible a nature, as to penetrate and destroy the 
 best crucibles. This glass enters into the composition of 
 flint-glass. It promotes its fusibility, renders it heavier 
 than other glass, better capable of bearing sudden 
 changes of temperature, and from its greater softness, 
 more suitable for cutting and polishing. 
 
 When lead is exposed to the atmosphere, the bright- 
 ness of its surface gradually diminishes, till it is nearly 
 of the same colour as the grey oxide produced by heat. 
 This oxide forms an even but a very superficial cover- 
 ing, and it defends the metal from any further change. 
 
 Most of the acids have an action on lead ; but for this 
 purpose the sulphuric acid must be concentrated and 
 boiling. Sulphurous acid gas escapes during the solution, 
 and the acid is decomposed. By distilling the solution 
 to dryness, a sulphate of lead is obtained : it is of a while 
 colour, and affords crystals. This sulphate is caustic, and 
 may be decomposed by lime and the alkalies. 
 
 The nitric acid has a strong action upon lead, which, 
 if concentrated, it converts into a white oxide ; but if di- 
 luted, it dissolves the metal, and forms nitrate of lead, 
 which is crystallizable. Lime, and the alkalies decom- 
 pose the nitric solution. Nitrate of lead decrepitates in 
 the fire, and is fused with a yellowish flame upon ignited 
 coals. Sulphuric acid will take lead from the nitric 
 acid, falling down upon being added to it, combined with 
 the metallic oxide. The muriatic acid carries down 
 the lead in the same manner, and forms a muriate of 
 lead formerly called plumbum corneum. This is soluble 
 in water. 
 
 If the nitric acid, of the specific gravity of 1.2GO, be 
 poured upon the red oxide of lead, 185 parts of the 
 oxide are dissolved; but 15 parts remain in the state of a 
 deep brown powder. This powder is the brown oxide 
 of lead : it contains 21 per cent, of oxygen. 
 
 The muriatic acid, assisted by heat, dissolves a part
 
 108 CHEMISTRY. 
 
 of the lead put into it, and oxidizes another part. The 
 strong affinity of the oxides of lead for muriatic acid, 
 causes them to decompose almost every substance in 
 which this acid is founJ, by combining with it. Thus, 
 when volatile alkali is obtained by distilling muriate of 
 ammonia with the oxides of lead, the residuum is muriate 
 of lead : the oxides of lead will even disengage the vola- 
 tile alkali in the cold. Muriate of soda is decomposed 
 if fused with litharge ; the lead uniting as in the last- 
 mentioned case with the muriatic acid, and forming a 
 yellow compound for the manufacture and use of which, 
 as a pigment, a patent has been obtained. 
 
 The acetous acid dissolves lead and its oxides. The 
 white oxide of lead, known in commerce by the name 
 of white lead', is prepared by its means. The lead is 
 cast in thin plates, which are rolled up in the manner of 
 a watch-spring, with a narrow space between each coil. 
 They are then placed vertically in earthen pots, which 
 contain a quantity of good vinegar, but their lower edge 
 is prevented from coming in contact with the vinegar by 
 suitable projections from the sides of the pots. The pots 
 are then covered, and bedded in tan in a close apart- 
 ment. The vapour of the acid slowly converts the sur- 
 face of the lead into a white oxide, which is separated 
 by shaking or uncoiling the plates. The plates are then 
 re-submitted to the same process, until nearly consumed, 
 when they are melted up, and cast over again. The 
 white oxide thus obtained, is prepared for sate by wash- 
 ing it in water, and drying it in the shade : it is then 
 called indiscriminately white lead or ceruse, though some 
 only give the name of ceruse to its mixture with chalk. 
 If white lead be dissolved in acetous acid, it affords a 
 crystallizable salt or acetate, which, from its sweet taste, 
 is called sugar of lead. From its effect in diminishing 
 acidity, sour wines have been sweetened by the addition 
 of white lead, a practice which merits the severest repro- 
 bation, as the oxides of lead are the most destructive 
 poisons, in whatever way received into the animal sys- 
 tem whether ir. solution, by breathing the dust which
 
 SILVER. 109 
 
 arises from them, or by working among them with the 
 hands. 
 
 The oxides of lead dissolve in oils, of which they cor- 
 rect the rancidity, and, therefore, they have sometimes 
 been added to the finer oils with fraudulent intentions. 
 Linseed and other drying oils are rendered still more 
 strongly desiccative by boiling upon oxide of lead. 
 
 Pure alkaline solutions corrode lead, and dissolve a 
 small quantity of it. 
 
 Phosphoric acid, if heated with charcoal and lead, 
 becomes converted into phosphorus, which combines 
 with the metal. This phosphuret differs not much from 
 common lead: it is malleable, and easily cut with a 
 knife ; but it sooner loses its brilliancy than common lead; 
 and by fusion the phosphorus is burnt, and the lead left 
 pure. 
 
 SILVER. 
 
 SILVER is the whitest of all metals, and next to gold, 
 it is the most malleable and ductile. Under the ham- 
 mer, the continuity of its parts is not destroyed, until its 
 leaves are not more than the T^OTO- of an inch thick ; 
 and it may be drawn into wire finer than a human hair. 
 
 The specific gravity of silver is 10.474 ; its hardness 
 is 6.5. It continues melted at 28 of Wedgewood; but 
 a greater heat is required to bring it into fusion. Its 
 tenacity is s.uch, that a wire of one-tenth of an inch in 
 diameter, will sustain a weight of 270 pounds, without 
 breaking. 
 
 Silver has neither smell nor taste. It is not altered 
 by the contact of air, unless containing sulphurous va- 
 pours; but it may be volatilized by an intense heat, and 
 Lavoisier oxidized it by the blow-pipe and oxygen gas. 
 By exposing silver twenty times successively to the heat 
 >f a porcelain furnace, Macquer converted it into glass, 
 )f an olive-green colour. 
 
 Silver is found, in greater or less abundance, in almost 
 ill countries which contain mines ; but the greatest quan- 
 tities of it are obtained from the mines of Peru and 
 JO
 
 110 CHEMISTRY. 
 
 Mexico. The celebrated mine of Potosi, which is situ- 
 ated near the source of the Rio de la Plata, is one of the 
 most considerable mountains of Peru; and this mountain 
 is described by travellers as filled with veins of silver 
 from the top to the bottom. 
 
 Silver is often found native in ramifications consisting 
 of octahedrons inserted in each other, also in small inter- 
 winded threads, and in masses ; but it is most commonly 
 "ound in combination with sulphur. 
 
 Silver forms allovs with most of the metals. Copper 
 is the metal with which it is alloyed for the purpose of 
 coinage. The British coinage contains 1 1 ounces 2 
 pennyweights of fine silver in the pound troy. Copper 
 stiffens silver, and increases its elasticity, but renders it 
 less ductile. 
 
 The alloy of silver and zinc is granulated on its sur- 
 face, and very brittle. Tin, also, in the smallest quanti- 
 ties, deprives silver of its malleability. Alloyed with lead, 
 silver ceases to be sonorous and elastic. 
 
 Fine filings of silver, triturated with mercury in a 
 warm mortar,, form an amalgam, which by fusion and 
 slow cooling, affords tetrahedral prismatic crystals, ter- 
 minated by pyramids of the same form. The mercury 
 cannot be separated from the silver, except by a much 
 stronger heat than would be required to volatilize it 
 alone. 
 
 The sulphuric acid dissolves silver, if concentrated and 
 boiling, and the metal in a state of minute division. The 
 action of the muriatic acid upon silver is very trifling, 
 unless oxygenized. 
 
 The nitric acid, a little diluted, has a powerful action 
 upon silver, of which it will dissolve half its weight. The 
 solution is at first blue ; this colour disappears when the 
 silver is pure ; but becomes green if it contains copper. 
 If the silver contains gold, this metal separates in black- 
 ish coloured flocks. The solution is extremely corrosive, 
 and destructive to animal substances. When the acid is 
 fully saturated, it deposits crystals as it cools, and also by 
 evaporation. Those crystals are called lunar ni>; ^, or
 
 SILVER. Ill 
 
 ntlrnte of silver. By fusion, for which a gentle heat is 
 sufficient, their water of crystallization is driven off; and 
 dlso a part of the acid, by which they become a subni- 
 trate ; this forms the lapis infernalis, or lunar caustic 
 of the surgeons; it is of a black colour, and usually cast 
 in the form of small sticks. A heat a little above what 
 is necessary for fusing the nitrate, separates the whole 
 of the acid, and the silver is revived. Lunar caustic 
 should be made of silver entirely free from copper, as 
 the copper is poisonous to wounds. 
 
 The causticity of this and all other mineral solutions, 
 is attributed to the strong propensity of the metal to 
 assume the metallic state; in consequence of which, it 
 readily parts with its oxygen to substances it is in con- 
 tact with ; and, therefore, such subs-tances as are capa- 
 ble of receiving the oxygen, virtually undergo a combus- 
 tion. 
 
 A solution of nitrate of silver in water, is perfectly 
 free from colour ; but it stains the skin, and all animal 
 and vegetable substances, an indelible black. It is 
 employed, in a weak state, to dye the human hair, and 
 when mixed with a little gum-water, forms a permanent 
 ink for marking linen. It is employed for staining mar- 
 ble and other stones. 
 
 Nitrate of silver is a most powerful antiseptic; a 
 12,000th part of it dissolved in water will render the 
 Water incapable of putrefaction, and it may be separated 
 at any time by adding some common salt. 
 
 Silver is precipitated from its solution in nitric acid bv 
 muriatic acid, in the form of a white curd, which, when 
 fused, forms a semi-transparent, and rather flexible mass, 
 resembling horn ; it was therefore anciently called luna 
 cornea or horn silver, and is supposed to have given rise 
 to some of the accounts we have of flexible glass. It is 
 a muriate of silver, soon blackens in the air, aud is 
 scarcely soluble in water 
 
 The muriatic acid does not dissolve silver, but has a 
 strong affinity for its oxide, and as the muriate of silver 
 is not very soluble in water, the nitrate of silver is em-
 
 112 CHEMISTRY. 
 
 ployed as a re-agent, to discover the presence of muriatic 
 acid in any liquid : for if it contains that acid, muriate oi 
 silver will fall down in a white cloud, on dropping nitrate 
 of silver into it 
 
 The nitric acid sold in the stores generally contains 
 muriatic or sulphuric acid, or both ; hence the nitrate of 
 silver is employed to free the nitric acid from the two 
 latter acids. For this purpose, nitrate of silver is poured 
 into it by degrees, until no more precipitate is produced 
 after which it is rendered clear by filtering. Nitric acia 
 thus purified, is called by artists precipitated aquafortis i 
 but it still contains some silver, from which it cannot be 
 freed except by distillation. 
 
 When mercury is added to the nitric solution of silvei, 
 a precipitation of the silver is formed, which, from ita 
 resemblance to vegetation, is called arbor Diance, or tree 
 of Diana. 
 
 A few drops of nitrate of silver, laid upon glass, with 
 a copper-wire in it, afford another beautiful precipitation 
 of the silver, in the form of a plant. 
 
 Silver supplies a fulminating- powder, incomparably 
 more dangerous than any other: the nitric solution of 
 fine silver is precipitated by lime-water ; the water is 
 decanted ; and the oxide is exposed for two or three days 
 to light and air. This dried oxide being mixed with 
 ammonia, or volatile alkali, assumes the form of a black 
 powder; decant the fluid, and leave the powder to dry 
 iu the open air. This powder is the fulminating silver, 
 which, after having been once made, can no longer be 
 touched ; it must therefore be left in the vessel in which 
 the evaporation was performed. It should never be 
 made but in minute quantities, and not more than the 
 fulmination of a grain should be attempted at once. 
 
 The avidity with which sulphur enters into combina- 
 tion with silver, is instanced by Proust, in its tarnishing 
 when exposed in churches, theatres, and other places, 
 much frequented by men. This tarnish soon becomes 
 a real crust, which, on examination, is found to be a sul- 
 phuret of silver. It can only be detached by bend'ojj
 
 NICKEL. 113 
 
 (he silver, or breaking the silver to pieces, and its colour 
 is a deep violet, like the sulphuret of silver formed by 
 fusion. Proust is of opinion that sulphur is constantly 
 formed and exhaled by living bodies. 
 
 The sulphuret of silver is brittle, and more fusible than 
 silver. By a sufficient heat alone, the sulphur is vola- 
 tilized, and the metal entirely recovered. 
 
 NICKEL. 
 
 NICKEL is a metal of greyish white colour, between 
 that of tin and silver ; but when not pure, it is reddish, 
 which is the colour of its ore. It is both ductile and 
 malleable, when cold and red-hot. Its specific gravity 
 is 9.000, and its hardness is 8. It is not fused at a less 
 heat than 150 of Wedgwood. 
 
 The ore of the nickel has been long known to the 
 miners of Germany, where, from its resemblance to that 
 of copper, it is called kupper-nickel, or false copper. 
 Bergman was the first who discovered that it contained 
 a peculiar metal. 
 
 Nickel is strongly attracted by the magnet, and at- 
 tracts iron. On this account, ifr was supposed to contain 
 iron ; but Chenevix and Richter discovered that a very 
 small portion of arsenic prevents nickel from being affect- 
 ed by the magnet. When it is not attractable, therefore, 
 the presence of arsenic may be suspected. To separate 
 arsenic from nickel, Chenevix boiled the compound in 
 nitric acid, till the nickel was converted into an arse- 
 niate, decomposed this by a nitrate of lead, and evapo- 
 rated the liquor not quite to dryness. He then poured 
 in alcohol, which dissolved only the nitrate of nickel 
 The alcohol being decanted and evaporated, he re-dis 
 solved the nitrate in water, and precipitated it by potass 
 The precipitate, well washed and dried, he reduced in 
 a Hessian crucible, lined with lamp-black, and found it 
 to be perfectly magnetic ; but this property was de- 
 stroyed again by alloying the metal with a small portion 
 of arsenic. 
 10*
 
 114 CHEMISTRY. 
 
 The kupfur-nickel of the Germans, is the sulphuret of 
 nickel, and besides generally contains arsenic, iron, and 
 cobalt. This ore is roasted, to drive off the sulphur and 
 arsenic, then mixed with two parts of black flux, put 
 into a crucible, covered with muriate of soda, and heated 
 in a forge furnace. The metal thus obtained, which is 
 still very impure, may be dissolved in diluted nitric acid, 
 and then evaporated to dryness; after this process has 
 been repeated three or four times, the residuum must be 
 dissolved in a solution of ammonia perfectly free from 
 carbonic acid. Being again evaporated to dryness, it is 
 now to be well mixed with two or three parts of black 
 flux, and exposed to a violent heat in a crucible, for half 
 an hour or more. 
 
 Richter says r that pure nickel is not liable to be 
 altered by the atmosphere; hence it is better adapted 
 than steel for compass needles. 
 
 By exposing nickel to heat with nitre, an oxid.e of it is 
 obtained of a greenish colour, if the metal be impure ; 
 but if otherwise, brown ; this oxide contains 33 parts in 
 the 100 of oxygen. 
 
 The French manufacturers of porcelain are said to 
 use the oxide of nickel in producing a delicate grass 
 green. A hyacinthine coloui may be given to flint-glass 
 by the same oxide. 
 
 Proust observes, that a certain proportion of nickel 
 increases the whiteness of iron, diminishes its disposition 
 to rust, and adds to its ductility. In Birmingham, it is 
 occasionally combined with iron and brass. The Chinese 
 also, employ it in conjunction with copper and zinc for 
 children's toys. It is the difficulty of working this metal, 
 rather than its scarcity, that renders it so little known. 
 Equal parts of copper and nickel form a red ductile 
 alloy. The alloys of it with tin and zinc are brittle. 
 Equal parts of silver and nickel form a white ductile 
 alloy. It does not amalgamate with mercury. Nickel 
 is soluble with most of the acids, but the action of the 
 sulphuric and muriatic is not considerable. The nitric 
 and nitrarnuriatic acids are -its proper solvents. The
 
 COPPER. * 115 
 
 Citric solution is of a fine green grass colour, and by 
 evaporation affords green crystals in rhomboidal cubes. 
 
 Cronsted found that nickel combines with sulphur bj 
 fusion, and that the result is hard and yellow, with small 
 brilliant facets; but the nickel which he employed was 
 impure. 
 
 Aickel combines readily with phosphorus, either by 
 fusion along with phosphoric glass, or by dropping phos- 
 phorus upon it while it is red-hot. The phosphuret of 
 nickel is of a white colour, and when broken, exhibits 
 the appearance of very slender prisms united together. 
 
 It is remarkable that all those bodies called meteoric 
 stones, which have at different times fallen from the 
 atmosphere, contain nickel. 
 
 COPPER. 
 
 COPPER is of a pale red colour, inclining to yellow. It 
 has a stypticand unpleasant taste, and emits, by friction, 
 a disagreeable smell. Its hardness is 8 ; its specific gra- 
 vity is 7.788. In point of malleability, it is not much 
 inferior to silver. It is sometimes found native. 
 
 If copper be made red-hot, in contact with air, its sur- 
 face rapidly oxidizes, and the oxide may be separated 
 by the hammer, or by plunging the oxide into water. 
 By the repetition of the process, another scale will be 
 formed ; and this may be continued, till the whole of the 
 metal disappears. These scales are a brown oxide of 
 copper, which contains 84 parts of copper, and 16 of 
 oxygen. This oxide may be converted into a brown 
 glass, by a strong heat. 
 
 When exposed to the air, copper becomes covered 
 with a green crust, which is the green oxide of copper. 
 This change takes place only at the surface, the oxide 
 itself forming a defence from further change. 
 
 Filings of copper, thrown upon burning coals, burn 
 with a greenish flame, and when the metal is kept in a 
 greater heat than what is necessary for its fusion, it burns 
 with a flame of the same colour.
 
 116 . CHEMISTRY. 
 
 Most of the alloys of copper have been already no 
 ticed. This metal, with iron, forms the alderado, 01 
 Keir's patent metal for window-frames, designed to com- 
 bine elegance with strength. Copper unites very readily 
 with antimony, and forms an alloy, distinguished by a 
 beautiful violet colour. 
 
 Concentrated sulphuric acid dissolves copper by the 
 assistance of heat, and the crystals of the solution, after 
 adding water to it, form a sulphate of copper, generally 
 called blue vitriol. If to this sulphate of copper be added 
 a solution of arseniate of potass, a beautiful green pre- 
 cipitate is formed, called Scheele's green, or mineral 
 green. Magnesia, lime, and the fixed alkalies, precipi- 
 tate copper from its solution in sulphuric acid, in the form 
 of an oxide. 
 
 The muriatic acid does not dissolve copper, unless con- 
 centrated and in a state of ebullition ; the solution is 
 green ; the muriatic is caustic and astringent, fuses by a 
 gentle heat, and congeals into a mass. 
 
 The nitric acid attacks copper with effervescence. A 
 large quantity of nitrous gas is disengaged. The acid 
 first oxidizes the metal, and then dissolves the oxide. 
 The solution has a blue colour, much deeper than that 
 by sulphuric acid, and affords crystals by slow evapora- 
 tion. Lime precipitates the metal of a pale blue ; fixed 
 alkalies, of a bluish white. Volatile alkali throws down 
 bluish flocks, which are quickly re-dissolved, and produce 
 a lively blue colour in the fluid. 
 
 The acetous acid highly concentrated, dissolves copper; 
 but when not concentrated, it only corrodes the metal, 
 and forms the oxide called verdigris. This oxide, dissolved 
 in vinegar, forms a salt called by the chemists crystallized 
 acetate of copper, and in commerce distilled verdigris. 
 
 Copper is precipitated from its solution by iron. The 
 iron is simply immersed in the solution ; the acid seizes 
 upon it, and abandons the copper. The copper obtained 
 by this means is called copper of cementation. Sulphate 
 of copper is frequently found in streams of water from 
 copper mines ; the quantity of salt which they contain is
 
 COPPER. 117 
 
 not sufficient to reimburse the expense of evaporating 
 the water to obtain blue vitriol ; but by throwing waste 
 pieces of iron into them, the salt is decomposed, and the 
 copper is precipitated in a metallic form, because the 
 sulphuric acid has a greater attraction for iron than 
 copper. It appears in effect as if the iron was changed 
 into copper, and to the superficial observer favours the 
 idea that metals are transmutable. The streams ot 
 mines thus containing sulphate of copper are often as 
 valuable as the ore itself. 
 
 All the salts of copper are poisonous ; and copper 
 vessels should therefore never be used to contain any 
 vehicle capable of holding the metal in solution. In 
 Sweden, the use of copper vessels for culinary purposes, 
 iias been prohibited by law, and a statue of the metal 
 dedicated to the man, at whose solicitation it was ob- 
 tained. 
 
 Sulphur combines with copper at a strong heat. 
 Sulphuret of copper is brittle, softer than copper, of a 
 black colour externally, and within of a leaden grey. 
 
 Jl phosphuret of copper may be formed by casting 
 phosphorus upon red-hot copper. It has the hardness of 
 steel, but is too brittle and refractory to be useful. 
 
 Prussic acid unites with the oxide of copper, and forms 
 a brown pigment, superior, both in oil and water, accord- 
 ing to the experience of Hatchet, to any other in use. 
 It has a purple tinge, so as to form various shades of 
 bloom or lilac when mixed with white, and which are 
 not liable to fade as those made with lake. The best 
 mode of preparing the prussiate of copper, is to dissolve 
 the green muriate in ten parts of distilled water, and 
 precipitate with prussiate of lime. 
 
 Fixed alkalies have some action on copper, with which 
 they form a light blue solution; the effect is greatest in 
 the cold. 
 
 Ammonia dissolves copper with much greater rapid- 
 ity than fixed alkalies, whether it be in the state of 
 metal or an oxide, and forms a beautiful blue solution. 
 This solution, when recently made, is colourless if the
 
 118 CHEMISTRY. 
 
 vessel be closed, but when the vessel is opened, the colour 
 returns, gradually extending from the surface downwards, 
 Oils appear to have no action on copper, until they 
 become rancid, in which case their disengaged acid cor- 
 rodes the copper, and the oil assumes a bluish green 
 colour. 
 
 IRON. 
 
 IRON is of a bluish white colour, highly elastic, sonor- 
 ous, has a styptic taste, emits a peculiar odour when 
 rubbed, and strikes fire with flint. In tenacity it exceeds 
 all metals ; wire of it, only one-tenth of an inch in dia- 
 meter, sustaining a weight of 450 pounds without break- 
 ing. Its specific gravity is 7.788. 
 
 Iron is less malleable than gold, silver, or copper ; it 
 is of all the rnetals in common use the most difficult of 
 fusion, but the nearer it approaches to fusion, the more 
 malleable and ductile it becomes. 
 
 The hardness of iron, its great tenacity, the facility 
 with which it may at a white heat be fashioned and 
 welded, are the properties which render it so valuable. 
 
 Iron is attracted by the magnet or loadstone, and is 
 itself capable of being rendered magnetic ; but this pro- 
 perty, after having been communicated to it, is retained 
 only a short time, unless it be in the state of hard steel. 
 
 If suddenly plunged into cold water, while red-hot, it 
 is rendered rather more rigid than before, but gradually 
 cooling, renders it soft. 
 
 Iron is sometimes found native. In the museum of the 
 academy of science at Petersburgh, is a mass of native 
 iron, 1200 tons in weight. 
 
 Cast-iron is that which results from the fusion of the 
 iron ore with charcoal : its peculiar properties are owing 
 to its containing carbon, and other foreign matters. 
 
 Steel is iron deprived of all impurities except a small 
 portion of carbon : it is more ductile than iron, and a 
 finer wire may be drawn from it than any other metal. 
 
 Iron, united with about nine-tenths of charcoal, forma 
 plumbago, or hyper-carburet of iron.
 
 IRON. 11S> 
 
 Iron has a greater affinity for oxygen than oxygen has 
 for hydrogen ; it therefore decomposes water by combin- 
 ing with its oxygen ; which is the cause of its being easily 
 altered by exposure to damp air or water. 
 
 The action of air, assisted by heat, converts a thick 
 pellicle of the surface of iron into a black oxide, contain- 
 ing 25 per cent, of oxygen ; and when this is hammerec 
 oft, another is quickly formed. This black oxide is at- 
 tracted in some degree by the magnet. If it be collected, 
 and exposed to a strong heat under a muffle, it becomes 
 a reddish brown oxide, containing 48 per cent, of oxy- 
 gen. The yellow rust formed when iron is long exposed 
 to damp air, is not a simple oxide, but contains a portion 
 of carbonic acid. Proust only admits two stages in the 
 oxidation of iron, viz. the green, and the brown, or red, 
 and considers the other supposed oxides to be mixtures 
 of these in various proportions. 
 
 The green oxide may be obtained by dissolving iron 
 in sulphuric acid, and then precipitating it by potass. 
 This oxide contains 27 parts of oxygen, and 73 of iron, 
 in the 100. By exposure to the air, it is converted into 
 brown oxide, which contains 18 parts of oxygen, as ob- 
 served above. 
 
 Concentrated sulphuric acid scarcely acts on iron, un- 
 less it be boiling ; but, if diluted with two or three times 
 its weight of water, it attacks the metal immediately, 
 and a strong effervescence ensues, without any heat but 
 that produced by the addition of the water. It is the 
 hydrogen gas of the water which escapes, the oxygen 
 being employed in oxidizing the metal ; which oxide the 
 acid dissolves without being decomposed. If heat be ap- 
 plied, more iron still is dissolved. This solution yields, 
 by evaporation, sulphate of iron. The common green 
 copperas of commerce is this salt in a state of impurity. 
 It is much more soluble in hot than in cold water; and, 
 therefore, a saturated solution of it in hot water affords 
 crystals in cooling, as well as by evaporation. 
 
 The substance called martial pyrites is a sulphuret 
 of iron, and it is from the decomposition of it, that the
 
 120 CHEMISTRY. 
 
 extensive demand for sulphate of iroi. is supplied. By 
 fusion with iron, sulphur produces a compound of the 
 same nature as pyrites. 
 
 The sulphuret of iron, as well as iron itself, burns 
 rapidly, but without noise, when triturated in a metallic 
 mortar with hyper-oxy muriate of potass. This mixture, 
 in a heap, if struck with steel, detonates strongly, and 
 gives out a red flame. 
 
 Sulphate of iron is decomposed by alkalies and by 
 lime. Caustic fixed alkali precipitates the iron in deep 
 green flocks, which are dissolved by the addition of more 
 alkali, and form a red tincture. The mild alkali does 
 not re-dissolve the precipitate it throws- down, which is 
 of a greenish-white colour. Distillation separates the 
 acid from sulphate of iron, and leaves the brownish-red 
 oxide called colcothar. 
 
 Astringent vegetables, such as gall-nuts, oak, tea, &c., 
 precipitate a fine black fecula from sulphate of iron, and 
 this precipitate remains suspended a considerable time in 
 the fluid, by the addition of gum-arabic, and hence its 
 utility as a writing ink. The well-known pigment called 
 prussian blue, is likewise a precipitate afforded by sul- 
 phate of iron. 
 
 Sulphur combines with iron merely by the assistance 
 of water; thus, if flowers of sulphur be mixed with iron 
 filings, and made into a paste with water, it soon becomes 
 hot, swells, and emits the well-known smell of hydrogen, 
 with watery vapours. The mixture takes fire, if in con- 
 siderable quantity, even although buried in the earth. 
 It is a composition, therefore, which rnay be used to form 
 an artificial volcano. 
 
 Concentrated nitric acid is rapidly decomposed by iron 
 a portion of the oxide of the acid oxidizes the iron, which 
 oxide dissolves as it is formed, and the remainder of the 
 acid passes off in j^trous gas. The solution is of a red- 
 dish brown, and deposits the oxide of iron after a certain 
 time, particularly if exposed to the air. Diluted nitric 
 acid afibrds a more permanent solution of iron, of a 
 greenish, or sometimes of a yellow colour. Neither of
 
 IRON. 121 
 
 the solutions aflbrds crystals, but both deposit the oxide 
 of iron by boiling, at the same time that the fluid assumes 
 a gelatinous appearance. This magma, by distillation, 
 afibrds fuming nitrous acid, much nitrous gas, and some 
 nitrogen, a red oxide being left behind. 
 
 Iron appears to be the only metal of which the solu- 
 tions, or combinations with oxygen, are not of a noxious 
 nature. The chalybeate waters form the best tonics 
 which medicine possesses. 
 
 The muriatic solution of iron, like all other solutions 
 of the same metal, is decomposed by lime and alkalies ; 
 but the precipitates are less altered, and may be easily 
 reduced, especially such as are produced by the addition 
 of caustic alkalies. Alkaline sulphurets, sulphuretted 
 hydrogen gas, and astringents, also decompose this as 
 well as the other solutions of iron. 
 
 Water charged with carbonic acid dissolves a con- 
 siderable quantity of iron. Vinegar appears to have 
 little or no effect upon iron, unless assisted by the air. 
 
 If equal parts of iron chippings, and phosphoric glass, 
 be melted together, a phosphuret of iron is obtained, 
 which is very brittle, and has a whitish fracture. Iron, 
 in its crude state, frequently contains phosphorus, which 
 renders cast-iron very refractory, and forms the kind 
 called cold-short iron, which is malleable when hot, 
 though brittle when cold. 
 
 Gold unites easily with iron, and becomes by this 
 union harder and less malleable. In the proportion of 
 six parts of gold and one of steel, the alloy may be 
 beaten into plates without cracking. The iron is only 
 partly separated by combustion in a glowing heat. Iron 
 has a stronger attraction than gold for the oxy-muriatic 
 and nitro-muriatic acids, and precipitates gold from these 
 acids in its metallic state. 
 
 Silver combines readily with iron. A mixture ot 
 fourteen parts of silve-. and two and a half iron, is more 
 elastic than silver, attracts the magnet, and is not decom- 
 posed in a strong fire. A small portion of iron does not 
 seem to injure the colour or malleability of the silver
 
 1 22 CHEMISTRY. 
 
 Iron precipitates silver from all its solutions in acids ; but 
 this happens in the nitric only, when the acid is not com 
 pletely saturated, or when nitrous gas is added. Muriate 
 of silver is decomposed in the dry way by its distillation 
 with iron filings. 
 
 Iron precipitates mercury in its metallic state from its 
 solution in acids. Distil with oxymuriate of mercury, 
 the muriate is decomposed, and fluid mercury produced. 
 
 Sulphate of iron precipitates mercury from its solution 
 in nitric acid, in its metallic state. 
 
 Lead is precipitated from its solutions in acids by iron. 
 Iron also precipitates nickel from its acid solutions, and 
 in the dry way takes from it the sulphur which it con- 
 tains. 
 
 Nickel has the strongest affinity for iron of all the 
 metals, and is separated from it with the greatest difficul- 
 ty. The alloy is fully as malleable, but less fusible than 
 iron alone. Nickel is precipitated only in a very imper- 
 fect manner by iron from its solutions in acids. 
 
 Iron unites in close vessels with arsenic, which renders 
 it more brittle, diminishes its attraction for the magnet, 
 and is separated from it with difficulty. 
 
 When iron has been covered with tin, the tin appears 
 to combine with it, and forms an alloy of greater depth 
 than would readily be supposed ; even a white heat is 
 insufficient to separate the tin entirely, yet till the whole 
 of it is removed, the iron will not weld. 
 
 TIN. 
 
 TUT is a white metal, intermediate between that ot 
 lead and silver ; it has little elasticity ; its taste is dis- 
 agreeable, and it has a peculiar smell, which increases 
 by friction. Its hardness is 6 ; its specific gravity 7.291 ; 
 is susceptible of very little increase by hammering. Its 
 purity is judged of by its levity, as it cannot be alloyed 
 with any metal lighter than itself. 
 
 The malleability of tin is such, that it may be extend- 
 ed intc leaves not more than the 2000th part of an inch
 
 TIN. 123 
 
 thick ; the tin-leaf called tin-foil, is, however, twice this 
 thickness. The tenacity of tin is but small ; a wire, one- 
 tenth of an inch in diameter, will support only about 49 
 pounds without breaking. Its flexibility is considerable; 
 it may be bent several times without breaking, emitting 
 at the same time a distinct crackling noise. 
 
 All the tin used in England is supplied by the mines 
 of Cornwall, which furnish 3000 tons annually. Its ores 
 occur most frequently in granite, but never in lime-stone. 
 It is very rarely found native. 
 
 Chaptal says, that if tin be kept in fusion* in a lined 
 crucible, and the surface be covered with a quantity of 
 charcoal to prevent its calcination, the metal becomes 
 whiter, more sonorous, and harder, provided the fire be 
 kept up for eight or ten hours. 
 
 The brilliant surface of polished tin soon becomes a 
 little tarnished by exposure to the air, but the effect is 
 very superficial and slight. 
 
 Mercury dissolves tin with great facility, and in all 
 proportions. To make this combination, heated mercury 
 is poured on melted tin ; the consistence of the amalgam 
 differs according to the relative proportions of the two 
 metals. 
 
 Nickel united to tin, forms a white and brilliant mass 
 Half a part of tin, melted with two parts of cobalt, and 
 the same quantity of muriate of soda, furnished Beaume 
 with an alloy in small close grains of a light violet 
 colour. 
 
 Equal parts of tin and bismuth, form a brittle alloy, 
 of a medium colo_ur between the two metals, and the 
 fracture of which presents cubical facets. 
 
 Zinc unites perfectly with tin, and produces a hard 
 metal, of a close-grained fracture. Its ductility increases 
 with the proportion of tin. 
 
 Antimony and tin form a white and brittle alloy 
 which is distinguished from other alloys of tin, by Ks pos- 
 sessing a less specific gravity than either of the two met- 
 als b^ which it is formed. 
 
 In combining arsenic with tin, precaution must be
 
 124 CHEMISTRY. 
 
 taken to prevent the arsenic from escaping by volatili' 
 zation. Three parts of tin may be put into a retor! 
 with one-eighth part of arsenic in powder ; fit on a re- 
 ceiver, and make the retort red-hot ; very little arsenic 
 rises, and a metallic lump is found at the bottom, con- 
 taining about one-fifteenth port of arsenic. It crystallizes 
 in large facets, is very brittle, and hard to melt. 
 
 If, tin be kept in fusion, with access of air, its surface 
 is speedily covered with a greyish pellicle, which is re- 
 newed as fast as it is removed. If this grey oxide be 
 pulverized" and sifted, to separate the uncalcined tin, and 
 calcined again for several hours under a muffle, it be- 
 comes the yellow oxide of tin, called among artizans 
 putty of tin, and extensively used in polishing glass, steel, 
 and other hard bodies. 
 
 A white oxide of tin is used in forming the opake kind 
 of glass called enamel. This composition is made by 
 calcining 100 parts of lead and 30 parts of tin in a fur- 
 nace, and then fluxing these oxides with 100 parts of 
 sand and 20 of potass. This enamel is white, and is 
 coloured with metallic oxides. 
 
 All the mineral acids dissolve tin, and it may be pre- 
 cipitated from its solutions by potass ; but an excess of 
 potass will re-dissolve the metal. Nitro-muriate of gold 
 is a test for tin in solution, with which it forms a fine 
 purple precipitate. 
 
 The sulphuric acid dissolves tin, whether concentrated 
 or diluted with water. Part of the acid is decomposed, 
 and flies off in the form of sulphurous acid gas. Heat 
 accelerates the effect of the aoid. Tin d>solved in sul- 
 phuric acid is very caustic. 
 
 The solution of tin in the nitric acid is performed 
 with astonishing rapidity, and the -metal is precipitated 
 Imost instantly in the form of a white oxide. If this 
 acid be loaded with all the tin it is capable of calcining, 
 and the oxide be washed with a considerable quantity 
 of distilled water, a salt may be obtained by evapora- 
 tion, which detonates alone in a crucible well-heated, 
 ind burns with a white and thick flame, Uke that oJ
 
 TIN. 1 25 
 
 phosphorus. The nitric acid holds but a very small 
 quantity of tin in solution, and when evaporated for the 
 purpose of obtaining crystals, the dissolved portion quickly 
 precipitates, and the acid remains nearly in a state of 
 purity. Nitric acid, much diluted, holds rather more 
 tin in solution, but lets it fall by standing, or by the ap- 
 plication of heat. 
 
 The muriatic acid dissolves tin, whether cold or hot, 
 diluted or concentrated. If fuming and assisted bv a 
 gentle heat, the addition of the tin instantly causes it to 
 lose its colour and property of emitting fumes, and a 
 slight effervescence takes place. The acid dissolves 
 more than half its weight of tin ; the solution is yellow- 
 ish, of a fetid smell, and affords no precipitate of oxide, 
 like the sulphuric and nitric acids. 
 
 The oxymuriatic acid dissolves tin very readily, and 
 without effervescence, because the metal quickly absorbs 
 the superabundant oxygen from the acid, and requires 
 no decomposition of the water to effect its oxidation. 
 
 Nitro-muriatic acid, made with two parts of nitric acid 
 and one of muriatic acid, dissolves tin with effervescence. 
 It is the solution of tin in this acid which the dyers em- 
 ploy to heighten the colour of their scarlet dyes. It is 
 prepared by adding small portions of tin at a time to the 
 common aquafortis of commerce ; when the appearance 
 of oxide is observed at the bottom of the jar, muriate of 
 soda is added, by which its solution is effected. If the 
 colour imparted by this solution is not bright, a little 
 nitrate of potass is added to it. 
 
 The acetous, and most vegetable acids, have some 
 action upon tin, particularly when aided by a gentle 
 heat ; but the solutions thus obtained, are not used in the 
 arts. 
 
 Tin decomposes the corrosive muriate of mercury. It 
 is for this purpose amalgamated with a small portion of 
 mercury, and this amalgam being first triturated in a 
 mortar with the corrosive muriate, the mixture is then 
 distilled by a gentle heat. A colourless liquor first passes 
 over, and is followed by a thick while vapour, which 
 11*
 
 126 CHEMISTRY. 
 
 issues with a kind of explosion, and covers the internal 
 surface of the receiver with a very thin crust. The 
 vapour becomes condensed into a transparent liquor, 
 which continually emits a thick, white, and very abun- 
 dant fume. It was formerly called the fuming liqucr o' 
 Libarius, and is the combination of the muriatic acid 
 and tin. 
 
 Tin has a strong affinity for sulphur; the sulphuret of 
 tin may be formed by fusing the two substances together 
 it is brittle, heavier than tin, and not fusible. It has a 
 bluish colour, a lamellatcd texture, and is capable of 
 crystallizing. 
 
 The white oxide of tin combines with sulphur, and 
 forms a compound called aurum musivum, or mosaic 
 gold, which is much used for giving plaster of Paris the 
 resemblance of bronze, and improving the appearance 
 of bronze itself. It is, also, occasionally used to increase 
 the effects of electrical machines. Chaptal recommends 
 for preparing it the process of the Marquis de Bouillon, 
 who directs an amalgam to be formed of eight ounces of 
 tin and eight ounces of mercury. In forming the amal- 
 gam, a copper mortar is heated, and the mercury poured 
 into it, after which the tin is added in a state of fusion 
 and the mixture triturated till cold. Six ounces of sul 
 phur and four of muriate of ammonia, are then mixed, 
 and the whole put into a matrass, v*<ch is to be placed 
 in a sand-bath, and heated to such a degree as to cause 
 a faint ignition in the bottom of the matrass. The fire 
 must be kept up for three hours. The aurum musivurr. 
 obtained by this process is usually excellent ; but if, 
 instead of placing the matrass on the sand, it be imme- 
 diately exposed upon the coals, and strongly and sudden- 
 ly heated, the mixture will take fire, and a sublimate 
 will be formed in the neck of the vessel, which consists 
 of the most beautiful aurum musivum that can be pre- 
 pared. 
 
 The mercury and muriate of ammonia are not in 
 strictness necessary to the production of aurum musivum. 
 Eight ounces of tin dissolved in muriatic acid, precipi<
 
 ZINC. 127 
 
 lated by the carbonate of soda, and mixed with four 
 ounces of sulphur, will produce a fine aurum musivum, 
 but without the property of exciting electrical machines. 
 A phosphuret of tin may be formed by melting in a 
 crucible equal parts of tin and phosphoric glass, or by 
 throwing small pieces of phosphorus into melted tin. The 
 phosphuret of tin may be cut with a knife ; it extends 
 under the hammer, but separates into laminae. When 
 newly cut, it has the colour of silver ; its filings resemble 
 those of lead, and the phosphorus takes fire when thej 
 are thrown upon burning coals. 
 
 ZINC. 
 
 Zi\c is a bluish white metal ; its specific gravity is 
 7.100; its hardness 6. It is distinguished by the singular 
 property of being neither malleable nor ductile, at com- 
 mon temperatures, but of acquiring both these qualities 
 at the temperature of 210 to 300 3 . It has neither taste 
 nor smell. It melts at the heat of about 700. 
 
 Zinc, at a red heat, burns with a bright white flame 
 and throws out white flakes, called flowers of zinc 
 These flowers are the white oxide of the metal ; they 
 are not volatile, but are merely driven ofi by the force 
 of the combustion. They contain more oxygen than the 
 grey oxide, which forms on the surface of the metal 
 when it is heated to fusion. The white oxide of zinc 
 may be converted into a yellow glass by a very violent 
 heat. 
 
 Zinc combines with most of the metals. With gold 
 it combines in all proportions. The alloy is very hard 
 and white when the metals are in equal proportions, and 
 takes a fine polish, without being very liable to tarnish. 
 One part of zinc is said to destroy the ductility of 100 
 parts of gold. 
 
 The alloy of silver and zinc is also brittle. Platina 
 unites with zinc, and forms a brittle fusible alloy, toler- 
 able hard, and of a bluish white colour, not so clear as 
 that of zinc.
 
 
 1 28 CHEMISTRY 
 
 One part of zinc, and two and a half of mercury 
 form by fusion an amalgam which becomes solid. It is 
 used to excite electrical machines. 
 
 The well-known alloy called brass, which is formed 
 of zinc and copper, is usually formed by cementing cop- 
 per in a close crucible with calamine, an ore which con- 
 tains zinc in the state of an oxide. 
 
 Tin and zinc combine readily ; the alloy is harder than 
 tin : lead and zinc also form alloys which are harder than 
 lead. Two parts of lead and three of zinc form a hard 
 alloy, which bears hammering without extending. 
 
 Iron and zinc have some affinity, as iron may be 
 coated with zinc instead of tin, for culinary vessels. The 
 solutions of zinc which may happen to be obtained, are 
 not dangerous like those of lead. 
 
 If water be thrown upon ignited zinc, a part of it it 
 decomposed : the oxygen converts part of the metul into 
 an oxide, and hydrogen gas escapes. 
 
 Sulphuric acid dissolves zinc without heat. A salt 
 may be obtained by evaporating the solution; this salt 
 which is a sulphate of zinc, is known by the name of 
 white vitriol ; it has a strong styptic taste. 
 
 The nitric acid powerfully attacks zinc, and produces 
 much heat; and a great part of the acid is decomposed; 
 but crystals may be obtained by the slow evaporation of 
 the residue. This salt, or nitrate of zinc, is deliques- 
 cent ; it melts upon heated coals, and decrepitates, pro- 
 ducing a slight reddish flame. If i* oe exposed to heat 
 in a crucible, it emits red vapo ~j. assumes the consis- 
 tence of a jelly, and preserve* this softness for a con- 
 siderable time. The nitric solution of zinc is very 
 caustic. 
 
 Muriatic acid also acts strongly upon zinc, with the 
 disengagement of much hydrogen gas. The solution, by 
 evaporation, does not crystallize, but assumes the consis- 
 tence of a jelly, which if distilled, allows some of the 
 acid to escape, and part of the muriate sublimes. 
 
 Most of the metallic and vegetable acids dissolve zinc 
 which is precipitated from its solution by earths and a!
 
 POTASSIUM. 1 29 
 
 kalies ; the latter re-dissolves the precipitate, if added 
 in excess. 
 
 Sulphur cannot be made to combine with metallic 
 zinc ; but it combines readily with the oxide of zinc. 
 
 Zinc may be combined with phosphorus by casting 
 small pieces of phosphorus upon the melted metal, which 
 should be covered with tallow or rosin to prevent its 
 oxidation. Phosphuret of zinc is white, with a shade oi 
 bluish grey, has a metallic lustre, and is a little malleable. 
 
 Zinc also combines with carbon, and forms a carburet 
 of zinc. It generally contains a small portion of carbon. 
 
 POTASSIUM. 
 
 THE fixed alkalies, potass and soda, are found not to 
 be simple bodies, as had once been supposed, but oxides, 
 each of them containing a peculiar metal in combination 
 with oxygen. They were analyzed by Sir H. Davy, in 
 a course of experiments which that distinguished chemist 
 undertook with the express view of discovering their 
 nature. He succeeded by means of the galvanic appa- 
 ratus in the following manner. 
 
 In his first experiments he acted upon aqueous solutions 
 of potass and soda, by a powerful voltaic combination, 
 but in this way he only obtained the decomposition of 
 the water of the solution. He then acted upon these 
 alkalies in a state of igneous fusion. The potass was 
 contained in a platina spoon, and was kept perfectly 
 fused in a strong red heat, by means of a stream of 
 oxygen gas, from a gasometer applied to the flame of a 
 spirit-lamp. The spoon was preserved in communication 
 with the positive side of the battery of the power of 100 
 plates of 6 inches, highly charged, and the connection 
 from the negative side was made by a platina wire 
 The advantage of this arrangement over the aqueous 
 solution was soon apparent. The potass seemed to be a 
 conductor in a high degree, and as long as the communi- 
 cation was preserved, a most intense light was exhibited 
 at the negative wire, and a column of flame, which
 
 V 
 
 130 CHEMISTRY. - 
 
 seemed to be owing to the development of combustible 
 matter, arose from the point of contact When the order 
 was changed, so that the platina spoon was made nega- 
 tive, a vivid and constant light appeared at the opposite 
 point ; there was no effect of inflammation around it, but 
 aeriform globules, which inflamed in the air, rose through 
 the potass. 
 
 As the products of the decomposition, which evidently 
 appeared to have taken place in the above experiment, 
 could not be collected, Sir H. Davy determined to apply 
 the galvanic electricity to the alkali in its usual state. A 
 small piece of potass, moistened a little by the breath, 
 was placed upon an insulated disc of platina, connected 
 with the negative side of a battery consisting of 100 
 plates of 6 inches, and 150 of 4 inches square, in a state 
 of intense activity, and a platina wire, communicating 
 with the positive side, was brought in contact with the 
 upper surface of the alkali. The whole apparatus was 
 in the open air. Under these circumstances, a vivid 
 action was soon observed to take place. The potass 
 began to fuse at both its points of electrization, and small 
 globules, having a high metallic lustre, and precisely the 
 same in characters to mercury, appeared, some of which 
 burnt with explosion and bright flame. These globules 
 are the basis of potass, which has received the name of 
 potassium, and appears fully entitled to rank among the 
 metals, as we shall proceed to show. 
 
 It next became a matter of considerable difficulty to 
 preserve and confine the basis of potass, in order to 
 examine its properties. Sir H. Davy found, at length, 
 that in recently distilled naphtha it may be preserved for 
 some days, and that its physical properties may easily be 
 examined in the atmosphere, when it is covered with "a 
 thin rilm of this liquid. 
 
 Potassium, at the temperature of 60, is only imper- 
 fectly fluid; at 70 it becomes more fluid; at 100 its 
 fluidity is perfect, so that different globules may easily 
 be made to run into one. At 50 it becomes a soft and 
 malleable solid, which has the lustre of polished silver
 
 POTASSIUM. 131 
 
 at about the freezing point of water, it becomes haid 
 and brittle, and when broken in fragments, exhibits a 
 crystallized texture, of a perfect whiteness and high 
 metallic splendour. To be converted into vapour, it 
 requires a temperature approaching to that of a red 
 heat. It is an excellent conductor of caloric and of 
 electricity. 
 
 Potassium will not sink in doubly distilled naphtha, 
 the specific gravity of which is 770. Its specific gravity 
 is to that of mercury as 10 to 223, which gives a pro- 
 portion to that of water nearly as 6 to 10, so that it is 
 the lightest fluid body known. Its levity is the physical 
 property in which it differs most materially from the rest 
 of the metals; yet between the lightest and heaviest of 
 the established metals, the difference is not much less, 
 than between the lightest of the established metals and 
 potassium. 
 
 When potassium is introduced into oxymuriatic acid 
 gas, it burns spontaneously, with a bright red light, and 
 muriate of potass is formed. When thrown upon water 
 it decomposes with great violence ; an instantaneous ex 
 plosion is produced, with a brilliant flame, and a solution 
 of pure potass is the result. When a globule is placed 
 upon ice, not even the solid form of two substances can 
 prevent their union ; for it instantly burns with a bright 
 flame, and a deep hole is made in the ice which is found 
 to contain a solution of potass. When a globule is 
 dropped upon moistened turmeric paper, it instantly 
 burns, and moves rapidly upon the paper, as if in search 
 of moisture, leaving behind it a deep reddish-brown 
 trace. 
 
 So strong is the attraction of the basis of potass for 
 oxygen, that it discovers and decomposes the small quan- 
 tities of water contained in alcohol and ether, even when 
 they are carefully purified. 
 
 When potassium is thrown into the mineral acids, it 
 inflames, and burns on the surface. 
 
 In sulphuric acid, sulphate of potass is formed ; in ni- 
 trous acid, nitrous gas is disengaged, and nitrate of
 
 CHEMIS1 
 
 132 ' CHEMISTRY. 
 
 potass is formed. When pressed upon a piece of phos 
 phorus, there is a considerable action ; the two sub 
 stances become fluid together, burn, and produce phos- 
 phate of potass. 
 
 When a globule of potassium is made to touch a 
 globule of mercury about twice as large, they combine, 
 with considerable heat. The compound is fluid at the 
 temperature of its formation, but when cool, it appears 
 as a solid metal, similar in colour to silver. If this alloy 
 be exposed to the air, it rapidly absorbs oxygen ; potass, 
 which deliquesces is formed, and in a few minutes the 
 mercury is found pure and unaltered. When a globule 
 of the amalgam is thrown into water, it rapidly decom- 
 poses it with a hissing noise ; potass is formed, hydrogen 
 disengaged, and the mercury remains free. 
 
 The amalgam of potassium and mercury dissolved all 
 the metals that were exposed to it ; and in this state of 
 union mercury acts on iron and platina. 
 
 Potassium combines with fusible metals, and the alloy 
 has a higher point of fusion than the fusible metal. 
 
 Potassium readily reduces the metallic oxides, when 
 heated in contact with them. It decomposes common 
 glass by a gentle heat, and at a red heat effects a change 
 even in the purest glass. 
 
 From a variety of experiments, Professor Davy con- 
 cludes, that 100 parts of potass, consist of about 84 basis, 
 and 16 oxygen. 
 
 SODIUM. 
 
 WHEN soda is exposed to the action of galvanic 
 electricity, in the same manner as the potass, in the 
 experiment above stated, a metal is obtained which is the 
 basis of the alkali, and is called sodium. 
 
 Sodium is white, and opaque, and when examined 
 under a film or naphtha, has the lustre and general ap- 
 pearance of silver. It is exceedingly malleable, and is 
 much softer than any of the common metallic substances. 
 A globule of it only one-tenth of an inch in diameter, 
 is easily spread over the surface of a quarter of an inch,
 
 
 SODIUM. 1 33 
 
 
 
 and this property does not diminish when it is cooled tc 
 32 of Fahrenhe'it. 
 
 By strong pressure, globules of sodium may be made 
 to adhere and combine into one mass ; so that the prop- 
 erty of welding, which belongs to iron and platina at a 
 white heat only, is possessed by this substance at common 
 temperatures. 
 
 Sodium conducts caloric and electricity in a similai 
 manner to potassium, and small globules of it inflame by 
 the voltaic electrical spark, and burn with bright explo- 
 sions. It is preserved under distilled naphtha in the 
 ame manner as potassium. 
 
 Its specific gravity is smewhat less than that of water, 
 being as .9348 to 1. It is therefore heavier than potassi- 
 um ; but the difference is so small, that we place them in 
 the order in which they were discovered. 
 
 Sodium has a much higher point of fusion than potas- 
 sium: its parts begin to lose their cohesion at about 
 120, and it is a perfect fluid at about 180 ; so that it 
 readily fuses under boiling naphtha. 
 
 But, though so easily fused, it remains in a state of ig- 
 nition at the point of fusion of plate glass. 
 
 The chemical phenomena of sodium are not very dif- 
 ferent from those of potassium. When exposed to the 
 atmosphere, it immediately tarnishes, and becomes 
 covered with a white crust, which deliquesces much 
 more slowly than that furnished by potassium. 
 
 The flame that sodium produces in oxygen gas is 
 white, and it sends forth bright sparks, occasioning a 
 very beautiful effect. In common air, it burns with light 
 of the colour of that produced during the combustion of 
 charcoal, but much brighter. 
 
 When introduced into oxymuriatic acid gas, it burns 
 vividly, with numerous scintillations of a bright red 
 colour. The substance produced by this combustion is 
 muriate of soua, (common salt.) 
 
 When thrown upon water, it produces a violent effer- 
 vescence, with a loud hissing noise ; it combines with the 
 oxygen of the water to form soda, and the hydrogen of 
 12
 
 ' v 
 
 134 CHEMISTRY. 
 
 I 
 
 the water is disengaged. This experiment exhibits no 
 luminous appearance. With hot water, the decompo- 
 sition is violent, and a few scintillations are observed at 
 the surface of the fluid ; but this is owing to small par- 
 ticles of sodium, which are thrown out of the water 
 sufficiently heated to burn in passing through the at- 
 mosphere. 
 
 Sodium decomposes the water of alcohol and ether, in 
 the same manner as the water in these fluids is decom- 
 posed by potassium. 
 
 It acts upon strong acids with great energy. With 
 nitrous acid, a vivid inflammation is produced: with 
 muriatic and sulphuric acids, there is much heat, but no 
 light. 
 
 Sodium, in its action upon sulphur, phosphorus, and 
 the metals, scarcely differs from potassium. It com 
 bines with sulphur in close vessels filled with the vapou, 
 of naphtha, with a vivid light, heat, and often with ex 
 plosion. The sulphuret is of a deep 'grey colour. 
 
 The phosphuret has the appearance of lead, and 
 forms phosphate of soda by exposure to air, or by com- 
 bustion. 
 
 One-fortieth part of sodium renders mercury a fixed 
 soda of the colour of silver, and the combination is 
 attended with a considerable degree of heat. 
 
 It makes an alloy with tin without changing its colour, 
 and it acts upon lead and gold when heated. In its state 
 of alloy, it is soon converted into soda by exposure to the 
 air. 
 
 Sir H. Davy concluded, that 100 parts of soda con- 
 sist of 76 or 77 of sodium, and 24 or 23 oxygen. 
 
 In concluding the communication to the Royal Society, 
 from which the preceding- view of the properties of 
 potassium and sodium is derived, Sir II. Davy justly 
 remarks, that an immense variety of objects of research 
 is presented in the powers and affinities of the new 
 metals produced from the alkalies. In themselves they 
 will undoubtedly prove powerful agents for analysis ; and 
 having an affinity for oxygen stronger than any other
 
 BISMUTH. 135 
 
 known substances, they may possibly supersede the appli- 
 cation of electricity to some of the undecomposed bodies. 
 In sciences kindred to chemistry, the knowledge of the 
 nature of alkalies, and the analogies arising in con- 
 sequence, will open many new views: they may lead tc 
 the solution of many problems in geology, and show that 
 agents may have operated in the formation of rocks and 
 earths which have not hitherto been suspected to exist 
 
 BISMUTH. 
 
 BISMUTH is known among artisans by the name of 
 tinglass. It is a metal of laminated texture, a pale 
 yellowish red colour; not ductile or malleable, but 
 reducible to powder under the hammer. Its specific 
 gravity is 9.822 ; its hardness is 6. It melts at the heat 
 of 460. 
 
 Bismuth sublimes when heated in close vessels; when 
 allowed to cool slowly, it crystallizes. It is not altered by 
 water, and though it tarnishes by exposure to the air, it 
 is not much changed. 
 
 Bismuth combines with most of the metals ; its general 
 effect is to increase their fusibility. The alloy of bis- 
 muth and platina is very brittle. When exposed to the 
 air, it assumes a purple, violet, or blue colour. The bis- 
 muth may be separated by heat 
 
 Equal parts of bismuth and gold form a brittle alloy, 
 not much paler than gold. 
 
 Equal parts of bismuth and silver form a brittle alloy 
 but less so than the last. The specific gravity of this 
 and the last alloy is greater than intermediate. 
 
 The amalgam of mercury and bismuth is more fluid 
 than mercury, and has the property of dissolving lead, 
 without having its fluidity lessened. 
 
 The alloy of copper and bismuth is not so red as 
 copper. 
 
 A small portion of bismuth renders tin brighter, hard- 
 ar, and more sonorous : it is often therefore an ingredient 
 in pewter Bismuth remarkably increases the fusion ci
 
 136 CHEMISTRY. 
 
 this metal: when the alloy consists of equal parts, it 
 melts at 280. 
 
 Bismuth does not combine with zinc, and its alloy with 
 iron, cobalt, arsenic, and antimony, is unknown. 
 
 The alloy of lead and bismuth is of a dark grey colour 
 a close grain, and very brittle. Eight parts of bismuth, 
 five of lead, and three of tin, form a metal which melts 
 at a heat not exceeding that of boiling water. Tea 
 spoons are made of this alloy, to surprise those unac 
 quainted with their nature : they have the appearanct 
 of common teaspoons, but are melted in hot water. 
 
 Bismuth expands as it cools, for which reason it is well 
 adapted for casting, and is sometimes added in the com- 
 position for printers' types, particularly the smaller sizes, 
 where a sharp perfect impression from the mould is ol 
 great importance. 
 
 Bismuth may be used in cupellation instead of lead, 
 and would for this purpose be preferable to lead, were 
 it not so much more scarce and expensive. 
 
 This metal, when exposed to a red heat, burns with a 
 faint blue flame, and emits yellowish fumes, which when 
 condensed, form what are called flowers of bismuth. 
 This oxide is converted into a greenish glass by strong 
 heat. 
 
 The sulphuric acid, when concentrated and boiling 
 has a slight action on bismuth. Sulphurous acid gas 
 escapes, and part of the metal is converted into a white 
 oxide. The sulphate of bismuth does not crystallize, 
 and is very deliquescent. 
 
 The nitric acid exerts a vehement action on bismuth. 
 Much heat, with a large quantity of nitrous gas, is 
 evolved. The solution, when saturated, affords crystals 
 as it cools. This nitrate detonates weakly, and leaves a 
 yellow oxide behind, which effloresces in the air. 
 
 The action of muriatic acid upon bismuth is very slow 
 and inconsiderable; and even for this effect the aci(? 
 must be highly concentrated. 
 
 Water precipitates bismuth from all its solutions: the 
 precipitate, which is a beautiful white, is when well
 
 ARSENIC. 137 
 
 washed, used as a cosmetic, under the name of magis. 
 tery of bismuth. It has, however, the disadvantage of 
 turning to a dark colour, by a very slight degree of sul 
 phurous effluvia ; and, as the metal resembles lead it 
 its noxious qualities, and is seldom free from arsenic, lik* 
 other mineral cosmetics, it cannot be used without dan 
 ger to the skin and the constitution. 
 
 Magistery of bismuth is sometimes mixed with poma 
 turn, for the purpose of staining the hair of a dart 
 colour. 
 
 Sulphur combines readily with bismuth by fusion 
 The sulphuret of bismuth is of a bluish-grey colour, am 
 crystallizes into beautiful tetrahedral need'les. It con 
 tains 15 parts in 100 of sulphur. 
 
 Phosphorus, dropped into melted bismuth, forms a phos- 
 phuret of the metal, which only contains about 4 parts 
 in the 100 of phosphorus. 
 
 ARSENIC. 
 
 ARSENIC is of a brilliant bluish-white colour, a lami- 
 nated texture, fusible, and very brittle. Its specific gra- 
 vity is 8.310; its hardness, 7. It soon tarnishes by 
 exposure to the air, becoming first yellowish, and then 
 black ; but, if immersed in alcohol, its metallic lustre 
 Buffers no diminution. It is one of the most combustible 
 metals, burns with a blue flame and the smell of garlic, 
 and sublimes in a state of arsenious acid. It is, in all 
 states, one of the most virulent poisons known. 
 
 When exposed to the air, arsenic is gradually con- 
 verted, by combining with oxygen, into a greyish-black 
 substance, which is the grey oxide of arsenic. If this 
 oxide be sublimed, the sublimate, having combined with 
 an additional dose of oxygen, forms the white oxide of 
 arsenic, which contains 7 parts in the 100 of oxygen. 
 This oxide glitters as if it were powdered glass ; it has 
 an acid taste, which terminates in an impression of sweet- 
 ness: it has a smell like garlic. This is the state ir 
 which the arsenic of commerce is met with. 
 12*
 
 138 CHEMISTRY. 
 
 The white oxide of arsenic may be converted into th< 
 metallic state by heating it with the oils, tallow, or char 
 coal, in close vessels ; but this is seldom necessary in the 
 arts, as it enters into combination with other metals from 
 the state of oxide. This oxide is soluble in 80 parts of 
 water, at the temperature of 60, and in 15 parts of 
 boiling water. When the solution is evaporated, the 
 oxide crystallizes; and when heated to 283 it sublimes; 
 if heated in close vessels, it becomes pellucid like glass, 
 but soon recovers its former appearance by exposure to 
 the air. The specific gravity of the glass is 5.000 ; of 
 the white oxide 3.706. 
 
 Almost the whole of the arsenic which is sold, is ob- 
 tained from the cobalt ores of Saxony, where long winding 
 flues are constructed, to the sides of which the sublimed 
 arsenic attaches itself. 
 
 Arsenic unites with most of the metals by fusion, and 
 a very small quantity of it has often a material effect. 
 
 Platina and arsenic form a brittle and fusible alloy ; 
 the arsenic may be driven off by a great heat. 
 
 Gold by fusion takes up about ^V^h of arsenic, with 
 which it forms a pale and brittle alloy. 
 
 Silver takes up one-fourteenth of arsenic. 
 
 Copper combines with five-sixths of arsenic, forming a 
 white, hard, and brittle alloy ; when the quantity is small, 
 it is both ductile and malleable ; it is called white tombac, 
 and is much used in the manufacture of buttons. 
 
 Iron is capable of combining with more than its own 
 weight of arsenic ; the alloy is white, brittle, and capable 
 of crystallization. 
 
 The alloy of tin and arsenic is harder and more 
 sonorous than tin, and has nearly the same external 
 appearance as zinc. Tin often contains a small quantity 
 of arsenic. 
 
 Lead takes up one-sixth of arsenic. The alloy is 
 Brittle and dark coloured. 
 
 Zinc takes up one-fifth of arsenic, antimony one-eighth, 
 and bismuth one-fifteenth. 
 
 Upon the whole, the effect of arsenic is, to whiten the
 
 ARSENIC. 139 
 
 red and dark coloured metals ; to give brittleness to the 
 ductile ; to increase the fusibility of the refractory, and 
 b render less fusible the rest Jt is added to the com 
 positions of the mirrors of reflecting telescopes, to increase 
 the density of the compound. 
 
 The sulphuric acid, boiled on the oxide of arsenic, 
 dissolves it; but the oxide precipitates as the solution 
 cools. 
 
 The nitric acid dissolves the oxide of arsenic, by the 
 assistance of heat, and forms a deliquescent salt. 
 
 The action of muriatic acid upon arsenic is very 
 feeble, whether assisted by heat or in the cold. The 
 sublimed muriate or butter of arsenic, is formed by mix- 
 ing equal parts of the yellow oxide of arsenic, and corro- 
 sive muriate of mercury, and distilling with a gentle 
 heat ; in the receiver will be found a blackish corrosive 
 liquor, which forms the sublimed muriate of arsenic. 
 
 Potass, boiled on the oxide of arsenic, becomes brown, 
 gradually thickens, and at last forms a hard brittle mass, 
 which is deliquescent arsenical salt. Soda affords, by 
 the same treatment, a product nearly similar. 
 
 The combination of arsenic and sulphur is often found 
 native, of a fine yellow colour; it is then called orpi- 
 ment ; this yellow sulphuret of arsenic may be prepared 
 artificially, by mixing sulphur with the white oxide of 
 arsenic, and heating them. It contains about 20 parts 
 of arsenic in the 100. If a stronger heat be applied, so 
 as to fuse this sulphuret, it assumes a scarlet colour, and 
 forms the compound called realgar, which contains 8C 
 parts of arsenic in the 100. It is the red sulphuret of 
 arsenic. Realgar is occasionally found native, as well a 
 orpiment. Lime and the alkalies decompose these sul 
 phurets. 
 
 The phosphuret of arsenic may be found by putting 
 equal parts of phosphoret and arsenic into a sufficient 
 quantity of water, and keeping the mixture moderately 
 hot some time. It is black and brilliant, and ought to bti 
 preserved in water. 
 
 The oxide of arsenic promotes the vitrificatior. of
 
 140 CHEMISTRY. 
 
 earths, but the glasses into which it enters are liable to 
 tarnish. 
 
 The workmen employed in the mines which produce 
 arsenic, are subject to violent complaints, and premature 
 death. When this deleterious mineral has been swal- 
 lowed, the sulphuret of potass (liver of sulphur) dis 
 solved in water, is prescribed as the most effectual anti 
 dote. Arsenic, whether alone or in a mixture, may be 
 distinguished by throwing it upon burning coals; as it 
 will afford white fumes and the smell of garlic. 
 
 ANTIMONY. 
 
 ANTIMONY is a brittle metal, of a white colour, inclin- 
 ing to grey, a laminated texture, exceedingly brittle, and 
 neither malleable nor ductile. It may be reduced to 
 powder. It has some taste, but no smell. Its specific 
 gravity is 6.860 ; its hardness, 6.5. It tarnishes but little 
 by the action of the air or water. It melts at a low red 
 heat, or 809 ; and, if the heat be much increased, it is 
 volatilized in white fumes. This white oxide of anti- 
 mony was formerly called argentine snow, or flowers of 
 antimony. 
 
 If antimony be brought to a white heat, and then 
 shaken, it takes fire, with a kind of explosion. If fused 
 on charcoal before the blow-pipe, and thrown into the 
 air, it divides into globules, and burns with a brilliant 
 white light as it falls to the ground. 
 
 The antimony of commerce is found in two states 
 that of crude antimony, and in the metallic state. Crude 
 antimony is the sulphuret of this metal, and is the only 
 ore of it which is obtained in sufficient quantity to be 
 wrought Metallic antimony, better known by the name 
 of regulus, is crude antimony deprived of its sulphur. 
 If iron filings be fused with crude antimony, they com 
 bine with its sulphur, and the antimony is obtained pure. 
 One-fifth of iron will combine with all the sulphur by 
 which this metal is mineralized. In the large way, an- 
 timony is obtained by melting calcined antimony with
 
 ANTIMONY. 141 
 
 dried wine-lees, in a reverberatory furnace, and the sul- 
 phur is often not wholly removed from it. Sulphuret of 
 antimony contains 26 parts in the. 100 of the metal. 
 
 Antimony will enter into combination with most of 
 .he metals. With platina, it affords a brittle alloy, which 
 is much lighter than platina. The platina cannot after- 
 wards be separated from it by heat. 
 
 Gold may be combined with antimony, by fusing them 
 together ; and the antimony may he separated by an in- 
 tense heat. 
 
 Silver and antimony form a brittle alloy, the specific 
 gravity of which is greater than intermediate between 
 the specific gravities of the two metals. 
 
 Mercury does not combine freely with antimony. Gel- 
 lert succeeded by using hot mercury, and covering the 
 whole with water. 
 
 Equal parts of lead and antimony, form a porous and 
 brittle alloy ; three parts of lead and one of antimony is 
 the best composition for printing-types; and of all the 
 alloys of antimony is the most useful. It forms a hard 
 alloy, scarcely malleable, but so brittle as to break with- 
 out bending, unless in very slender pieces; when pro- 
 perly prepared, its fracture has the appearance of that 
 of cast-steel. In fusing the two metals, the antimony 
 should be well mixed by stirring, as from its levity it 
 will float on the lead ; if the mixture has not been com- 
 plete, the alloy breaks with brilliant facets. This alloy 
 is more fusible and fluid than either of the metals sepa- 
 rately, and as antimony expands in cooling, it takes a 
 sharp impression of a mould. Bismuth is sometimes 
 added to increase this property, as well as the fusibility 
 but this metal is too costly to be added in any useful pro- 
 portion, except for the smallest types. The antimony 
 should be completely freed from sulphur, otherwise the 
 types made of it undergo a spontaneous decomposition, 
 easily break, and are covered with a black crust. 
 
 Twelve parts of lead and one of antimony, form an 
 alloy very malleable ; yet much harder than lead ; 16 
 parts of lead and one of antimony, form* an alloy which 
 does not differ from lead, except in being rather harder
 
 142 CHEMISTRY. 
 
 Copper combines readily with antimony; the colour of 
 the alloy is a beautiful violet, and its specific gravity is 
 greater than intermediate. 
 
 The alloy formed by iron and antimony is brittle and 
 hard ; its specific gravity is less than intermediate. The 
 disposition 'of iron to receive magnetism, is much im- 
 paired by antimony. 
 
 The alloy of tin and antimony is harder than tin 
 white, and brittle : the specific gravity is less than inter 
 mediate, yet the combination is so intimate, that it is 
 scarcely possible to separate the antimony from the tin. 
 A small portion of antimony is added with tin to form 
 pewter. 
 
 Le Sage analyzed some nails intended for ship-build- 
 ing, and found them to consist three parts tin, two of 
 lead, and one of antimony. These nails could be made 
 to penetrate oak boards, and were not acted upon by 
 sea-water. 
 
 The alloy of zinc and antimony is brittle. 
 
 Pure pewter has some action upon antimony, for it 
 becomes purgative by standing in a vessel made of this 
 metal. 
 
 Sulphuric acid, boiled upon antimony, is slowly de- 
 composed. Sulphurous gas escapes, and sulphur, itself, 
 by continuing the process. The sulphate of antimony is 
 deliquescent, and decomposed by the fire. 
 
 The nitric acid is decomposed by antimony very readi- 
 ly; a considerable part of the antimony is oxidized, and 
 part of the oxide is dissolved. This oxide is very white, 
 and difficult of reduction. 
 
 The muriatic acid acts freely upon antimony, except 
 by long digestion. The muriate of antimony, obtained 
 by evaporation, is very deliquescent : it is fusible in the 
 fire, and volatile. 
 
 Two parts of corrosive muriate of mercury, and one 
 of the muriate of antimony, distilled by a gentle heat, 
 afford the common butter of antimony, or sublimed mu- 
 riate of antimony. This preparation is fluid at a gen- 
 tle heat; by plunging the vessel which contains it intis 
 hot water, it becomes sufficiently fluid to pcur out
 
 ANTIMONY. 1 43 
 
 When batter of antimony is dropped into water, part 
 of the metal, in the form of an oxide, is thrown down in 
 a white powder. This substance is called powder of 
 algaroth, which acts as a strong purgative. 
 
 If sulphuret of antimony be melted, and the heat con- 
 tinued, the sulphur sublimes, and the antimony is con- 
 verted into a grey oxide ; this oxide may likewise be 
 obtained by powdering metallic antimony, and then 
 submitting it to calcination. The oxide will combine 
 with -p-Jj- of sulphur, and this compound forms, by fusion, 
 a glass called the glass of antimony. 
 
 Antimony supplies medicine with some of the most 
 active and valuable remedies. The acid of tartar forms 
 with it the preparation called emetic tartar, the new 
 name of which is antimoniated tartrate of potass : it is 
 composed of 56 parts tartrate of antimony, 36 tartrate 
 of potass, and S of water. 
 
 The alkalies and lime decompose the antimoniatea 
 tartrate of potass. 
 
 The alkalies alone have no perceptible action on anti- 
 mony, but the alkaline sulphurets dissolve it completely. 
 Kermes' mineral, a medicine formerly of great celebrity, 
 is a red sulphuretted oxide of antimony. It is prepared 
 by boiling together half a pound of the sulphuret of 
 antimony in powder, and two pounds of potass, in eight 
 pints of pure water, for fifteen minutes; stirring the mix- 
 ture with an iron spatula ; and then expeditiously filter- 
 ing it whilst it is hot. The liquor is now suffered to stand 
 in a cool place, where it soon deposits a powder that 
 must be repeatedly washed, first with cold, and after- 
 wards with hot water, till deprived of taste. The anti- 
 mony may be used again, until entirely consumed. Ac- 
 cording to the quantity which is taken, Kermes' mineral 
 operates as an emetic, purgative, sudorific, or expecto- 
 rant; its active properties render half a grain in most 
 cases sufficient at a time. 
 
 Phosphorus, thrown in small pieces upon melted anti 
 mony, combines with it. The phosphuret of antimony 
 is of a white colour, brittle, and appears laminated when 
 broken.
 
 144 CHEMISTRY. 
 
 TELLURIUM. 
 
 TELLURIUM is a recently discovered metal, nearly white 
 like tin, but varying a little to the .greyness of lead. Its 
 fracture is laminated. It is extremely brittle, and nearly 
 as fusible as lead. When heated with the blow-pipe 
 upon charcoal, it burns with a very lively flame, of a 
 blue colour, inclining at the edges to green. It is so 
 volatile as to rise entirely into a whitish grey smoke, 
 and exhales an odour like that of radishes. The smoke 
 condenses into a white oxide. Its specific gravity is 
 6.115. 
 
 Klaproth, who discovered this metal, found it in an ore 
 called the auriferous ore, otherwise aurum paradoxicum, 
 which is obtained in Transylvania^ and which contains 
 but a very small quantity of gold. 
 
 Tellurium amalgamates with mercury by trituration. 
 It is oxidized and dissolved in the principal acids. To 
 sulphuric acid it gives a deep purple colour, and if this 
 acid has been diluted with two or three parts of water, 
 and a little nitric acid added, a considerable portion of 
 tellurium will dissolve in it, and the solution will not be 
 decomposed by water. The solution in sulphuric acid 
 alone is separated in black flakes, and heat throws down 
 a white precipitate. 
 
 With nitric acid, tellurium forms a colourless solution, 
 which remains so when diluted, and affords slender, den- 
 dritic crystals by evaporation. 
 
 Tellurium dissolves in nitro-muriatic acid ; the solution 
 is transparent, and the addition of water precipitates a 
 'white powder, which is soluble in muriatic acid. Alcohol 
 produces a similar precipitate. 
 
 Iron, tin, zinc, and antimony, precipitate tellurium 
 from its acid solutions in a metallic state, under the form 
 of small black flakes, which resume their splendour by 
 friction, and which on burning charcoal rapidly melt into 
 a metallic button. 
 
 The alkalies throw down from the solutions of telluri- 
 um a white precipitate, which is soluble in all the acid ;, 
 h an excess of the alkili^s or their carbonates
 
 TUNGSTEN. 145 
 
 TUNGSTEN. 
 
 TUXGSTEIV is externally of a brown colour, internally 
 of a steel grey. Its specific gravity is 17.GOO, and it 
 is extremely difficult of fusion. 
 
 This metal is in Sweden obtained from an ore in which 
 its oxide exists in combination with lime ; in Germany 
 and England, it may be obtained from a mineral called 
 wolfram, in which it exists in combination with iron. 
 The oxide of tungsten has acid properties, and is there- 
 fore called lungstic add. 
 
 D'Elhuyart found that wolfram contained -f^ of tung- 
 stic acid ; the rest of it consisted of iron, manganese, and 
 tin. This acid substance being mixed with charcoal 
 powder, was violently heated in a crucible: after it had 
 cooled, a button of metal was found of a dark brown 
 colour, which crumbled to pieces between the fingers. 
 On viewing it with a glass, it was found to consist of a 
 congeries of metallic globules, some of which were as 
 large as a pin head. These globules were the tungsten ; 
 the charcoal had combined with the oxygen of the acid 
 substance, and left the metal pure. When heat is ap- 
 plied with access of air, tungsten is converted into a 
 yellow powder, composed of 80 parts of tungsten, and 
 20 of oxygen. This is the yellow oxide of tungsten, or 
 tungstic acid. 
 
 Vauquelin considers that the substance formed by 
 combination of tungsten with oxygen, does not possess 
 the properties generally attributed to acids ; since it is 
 insoluble in water, does not change the blue vegetable 
 colours, and has no apparent savour. He advises it 
 therefore to be called merely an oxide of tungsten, ob- 
 serving that Scheele, who regarded it as an acid, never 
 obtained it but in a triple combination, which possesses 
 a:id properties. 
 
 Morveau asserts that the oxide of tungsten renders 
 vegetable colours so fixed as not to be acted upon by the 
 ox\ muriatic acid 
 
 13 K
 
 146 
 
 CHEMISTRY. 
 
 Neither the sulphuric, the nitric, nor the muriatic 
 acid dissolves either tungsten or its oxide. 
 
 The alloys of tungsten, and the uses to which the 
 metal itself may be applied, appear to be little known. 
 
 Solutions of caustic potass, soda, and ammonia, 
 dissolve the oxide of tungsten, even in the cold, form- 
 ing tungstale of potass, soda, and ammonia. 
 
 Tungsten refuses to unite with sulphur. 
 
 A tungstate of magnesia is formed, by mixing oxide 
 of tungsten with carbonate cf magnesia and water, 
 boiling the mixture, and straining it. An acid will 
 precipitate a white powder; and, by evaporation, a 
 white salt is obtained, which crystallizes in little 
 bright spangles, and is unchangeable in air. 
 
 RHODIUM. 
 
 RHODIUM is one of the new metals obtained from 
 grains of crude platina. Its specific gravity is about 
 11. It is not malleable, and has never been perfectly 
 fused alone. Sulphur and arsenic render it fusible, 
 and may afterwards be expelled by heat. 
 
 Rhodium unites readily with every metal which Dr. 
 Wollaston, its discoverer, tried, except mercury. With 
 gold or silver, the alloy is malleable, not oxidized by a 
 high degree of heat, but becoming encrusted with a 
 black oxide when slowly cooled. One sixth of it does 
 not perceptibly alter the colour of gold, but renders it 
 much less fusible. Neither the nitric, nor the nitro-rr -i- 
 riatic acid acts on it in the state of alloy with golu 
 silver, but, if it be fused with three parts of bismmii, 
 lead or copper, the alloy is entirely soluble in a mix- 
 ture of nitric, mixed with two parts of muriatic acid. 
 
 URANIUM. 
 
 URANIUM is of a dark grey color on the surface, 
 within, it is a pale brown. Its hardness is about 6. It 
 is more difficult of frsion than manganese. It is li.'cle
 
 COBALT. 147 
 
 known and appears not to be obtained in a state of 
 purity as the specimens of different chemists have 
 varied in specific gravity from 6.440 to 9.000. 
 
 Klaproth discovered uranium in a mineral called 
 peach-blend, which is obtained in Saxony, and which had 
 been usually considered as an ore of zinc or iron, or even 
 tungsten ; but Klaprotli's analysis evinced that it was the 
 sulphuret of uranium. 
 
 When exposed for some time to a red heat, in a close 
 vessel, uranium suffers no change; but by means of 
 nitric acid, it is converted into a yellow oxide. This 
 oxide is soluble in diluted sulphuric acid gently heated, 
 and affords prismatic crystals of a lemon colour. It is 
 also soluble in nitromuriatic acid, and may be precipi 
 tated by alkalies. 
 
 COBALT. 
 
 COBALT is of a whitish colour, inclining to a bluish or 
 steel grey. When pure, it is somewhat malleable while 
 red hot, and is also attracted by the magnet. Its hard- 
 ness is 8, and its specific gravity is usually about 7.811. 
 It is brittle, and has a dull, close-grained fracture. It is 
 not acted upon by water, but tarnishes in the air; it 
 requires, for its fusion, a heat not inferior to that for cast- 
 iron. It has never been volatilized. 
 
 Cobalt has been found native ; but mostly in the state 
 of an oxide, united with arsenic, sulphur, iron, &c. It 
 is plentiful in the mines of Saxony; ^nd is also abun- 
 dantly obtained in the Mendip Hills, Somersetshire, Eng- 
 land, and in a mine near Penzance, in Cornwall. 
 
 Arsenical cobalt is of a greyish colour, and becomes 
 black by exposure to air. The sulphurous ore of cobalt 
 resembles the grey silver ore in its texture. 
 
 When the oxide of cobalt has been freed from arsenic 
 and sulphur, which is done by pulverizing it, washing it, 
 and then exposing it to a strong heat, it has an obscure 
 grey colour, and is called zaffre. When zaffre is fused 
 with three parts of pulverized flints, and one of potass 
 a beautify blue glass is obtained. This glass, when
 
 148 CHEMISTRY. 
 
 pulverized and washed, constitutes the smalt of com 
 merce. Smalt is used to give the blue colour to writing 
 paper, to starch, and linen. It also supplies a blue colour 
 to the painters of earthenware and porcelain, and to 
 enamel lers. 
 
 Metallic cobalt may be obtained by fusing zaffre in a 
 white heat, with three times its weight of black flux 
 the cobalt, when reduced, sinks to the bottom of the cru 
 cible. Or it may be obtained by fusing smalt with six or 
 eight times its weight of soda. 
 
 Cobalt resists cupellation, nor will it amalgamate with 
 mercury. It forms alloys with few of the metals : that 
 with tin is of a light violet colour. The metals with 
 which it combines most readily are arsenic and iron: 
 these, when combined with it, are separated with diffi- 
 culty. With iron, the alloy is hard, and not easily 
 broken : with arsenic, it is brittle, fusible, and more easily 
 oxidized than pure cobalt. 
 
 To dissolve cobalt in sulphuric acid, the acid must be 
 concentrated, and distilled upon it almost to dryness. 
 By washing the residuum, a portion of it dissolves in the 
 water: this portion is sulphate of cobalt. The other 
 part consists of oxide of cobalt. The cobalt may be 
 precipitated from the water by lime and alkalies. 
 
 Nitric acid dissolves cobalt by the assistance of a gen 
 tie heat. Lime and alkalies precipitate it from its solu 
 tion ; and an excess of alkali dissolves the precipitate. 
 
 Muriatic acids does not dissolve cobalt without the 
 assistance of heat. The nitro-muriatic acid dissolves 
 cobalt more readily. This solution, much diluted, forms 
 the much-admired sympathetic ink, which, when written 
 with upon paper, is invisible ; but, when the paper is 
 warmed, the characters appear of a beautiful green, 
 that gradually disappears as the paper cools ; and the 
 experiment may be repeated with the same result for an 
 indefinite number of times. 
 
 Sulphur is not readily combined with cobalt by art ; 
 but alkaline sulphurets readily form the combination. 
 
 Th phosphuret of cobalt may be formed by dropping
 
 MOLYBDENUM. 140 
 
 small pieces of phosphorus upon ignited cobalt in grains 
 It is white and brittle, and soon loses its lustre by expo- 
 sure to the air : it is more fusible than cobalt. 
 
 V 
 
 MOLYBDENUM. 
 
 THE ore containing molybdenum has almost the ap- 
 pearance of plumbago, and therefore, though scaly and 
 more shining, it was, before it was carefully analyzed, 
 mistaken for that mineral. It' is unctuous to the touch, 
 soils the fingers, and makes whitish and brilliant traces 
 upon paper, whereas the traces of plumbago are dull. 
 It has never been perfectly reduced ; when made into a 
 paste with linseed oil, or any other suitable substance, 
 the strongest fires only agglutinate it in brittle masses, 
 consisting of small grains. These grains are of a whitish 
 yellow colour, but their fracture is a whitish grey. Their 
 specific gravity is at least 7.500. 
 
 The alloys of molybdenum have been little examined ; 
 those with silver, iron, and copper, are friable; those 
 with lead and tin pulverulent and fusible. 
 
 Molybdenum, by a strong heat, is gradually converted 
 into a whitish coloured oxide. Nitric acid, which has a 
 rapid action upon it, converts it into a white oxide. This 
 oxide has the properties of an acid, and is therefore called 
 molybdic acid. It dissolves in 576 parts of water at a 
 mean temperature. It decomposes the solutions of soap, 
 and precipitates alkaline sulphurets. 
 
 The muriatic acid has no action upon molybdenum, 
 but dissolves its acid, which is also done by the sulphuric. 
 Heat should be employed with both these acids. 
 
 Scheele discovered, 1, that fixed alkali rendered 
 molybdic acid more soluble in water; 2, that salt pre- 
 vents the acid of molybdenum from volatilization by 
 heat ; 3, that molybdate of potass falls down by cooling, 
 in small crystalline grains, and that it may likewise be 
 separated from its solvent by sulphuric and muriatic 
 acids. 
 
 Blue carmine is prepared by precipitating tin from iti 
 13*
 
 150 CHEMISTRY. 
 
 solution in muriatic acid with the molybdate of potass, 
 The muriatic acid unites with the alkali, and the molyb- 
 dic with the tin, to form the blue precipitate. 
 
 % 
 
 MANGANESE. 
 
 A MINERAL, called the soap of glass, has been employed 
 for time immemorial in the manufacture of glass, which 
 it whitens and renders colourless. It is usually of a grey 
 or blackish colour, and soils the fingers. This mineral is 
 the oxide of a peculiar metal called manganese. 
 
 Metallic manganese is of a greyish white colour, brit- 
 tle, though not easily broken, and devoid of malleability. 
 When reduced to powder, it is attracted by the magnet 
 Its specific gravity is 6.990 ; its hardness is 8. It is more 
 difficult of fusion than iron. 
 
 When manganese is exposed to the atmosphere, it soon 
 tarnishes, and becomes at last black and friable ; heat 
 accelerates this change ; which produces the substance 
 called black oxide of manganese. It is this oxide of the 
 metal which is usually employed in the arts, and in which 
 state manganese is generally found. The counties of 
 Somerset and Devon supply large quantities of it, and in 
 the vicinity of Aberdeen, a mine of it has been lately 
 discovered, which furnishes twenty tons per week. 
 
 The black oxide of manganese contains 25 per cent, 
 of oxygen; a portion of this oxygen is separated by heat, 
 and, therefore, the oxide has recently become important, 
 for the purpose of furnishing this gas. When manganese 
 is employed in preparing oxymuriatic acid for medicine, 
 the purest, such as that from Upton Pyne, should be 
 used. That from Bristol and the Mendip Hills, generally 
 contains lead. 
 
 Manganese is susceptible of three different degrees of 
 oxydizemcnt, forming the white, the red, and the black 
 oxides of manganese. An oxide containing still more 
 oxygen is asserted to be of a dark green. 
 
 Metallic manganese may be obtained, by mixing the 
 black oxide 'nto a ball with linseed oil ; putting this ball
 
 TANTALIUM. 151 
 
 into a cavity made in a lump of charcoal, covering il 
 with a layer of charcoal, enclosing the whole in a cruci- 
 ble, and subjecting it to an intense heat for one or tvve 
 hours. Saline fluxes should be rejected for reducing 
 his mineral, because it has so strong a disposition to 
 vitrify, that it would be suspended in a flux of that kind. 
 
 Manganese unites by fusion with all the metals except 
 mercury. With copper and iron it appears to combine 
 the most readily ; but none of its alloys are used in the 
 arts, or known to be valuable. 
 
 The sulphuric acid attacks manganese, and produces 
 hydrogen gas ; the solution goes on more slowly than 
 that of iron in the same acid ; it is colourless. Sulphuric 
 acid extricates from the oxide of manganese, a large 
 quantity of oxygen gas. 
 
 The oxide of manganese is dissolved by nitric acid ; 
 muriatic acid, digested upon it, seizes its oxygen, and 
 passes in vapour through the water. This vapour is 
 oxymuriatic acid. 
 
 The oxide of manganese combines with the alkalies. 
 It also combines with sulphur, which the metal does 
 not. 
 
 Manganese at a red heat combines with phosphorus, 
 The phosphuret is of a white colour, brittle, granulated, 
 disposed to crystallize, not altered by exposure to the air, 
 and more fusible than manganese. 
 
 TANTALIUM. 
 
 FROM a fossil called tantalite, and another called ytro- 
 tantalite, Ekeberg extracted by means of the fixed 
 alkalies, a white powder, which he ascertained to be the 
 oxide of a peculiar metal. To this metal he gave the 
 name of tantalium. 
 
 When the oxide of tantalium above mentioned is 
 powerfully heated with charcoal, a button of metal is 
 obtained, with a metallic lustre externally, but internally 
 black and without brilliancy. Its hardness is 7 ; its 
 specific gravity 6.5. The acids will reduce it again tc
 
 152 CHEMISTRY. 
 
 the state of white oxide, but they \vill not dissolve h 
 The oxide is not changed by a red heat. Caustic fixed 
 alkali is the only re-agent which has any action upon it. 
 
 TITANIUM. 
 
 TITANIUM is of a brownish red colour, almost like cop- 
 per. Its lustre is considerable, it is brittle, and very 
 difficult of fusion. Its specific gravity is 4.18; its hard- 
 ness 9. 
 
 Titanium is obtained from a mineral, plentiful in Hun- 
 gary, called red schorl, which is its native red oxide ; 
 and from another mineral obtained in Cornwall, called 
 manacanite. 
 
 Vanquelin obtained metallic titanium from its native 
 red oxide, by mixing together 100 parts of this oxide 
 with 50 of calcined borax, and 50 of charcoal, formed 
 into a paste with oil ; and exposed the whole to the heat 
 of a forge raised to 160 of Wedgwood. 
 
 This metal is acted upon by the principal acids, except 
 the nitric, and forms salts with them. It also combines 
 with phosphorus. The phosphuret is of a pale white 
 colour, brittle, granular, and infusible by the blow-pipe 
 
 The attempts to alloy titanium have not succeeded. 
 
 CHROMIUM. 
 
 CHROMIUM is of a whitish colour, inclining to grey ; it 
 is very brittle ; its fracture presents a radiated appear- 
 ance, needles crossing in different directions, with inter- 
 stices between them. It is difficult of fusion, resisting the 
 beat of the blow-pipe. 
 
 Chromium was discovered by Vanquelin, in analyzing 
 a beautiful mineral called red lead of Siberia. The 
 mineral is a chromate of lead, in which chromium exists 
 in the state of an acid. Its colour is a fine aurora red, 
 with considerable lustre. Chromium has also been found 
 united with iron, forming chromate of iron ; it also exists 
 in some gems, of which it appears to constitute the col
 
 CHROMIUM. 153 
 
 miring principle. In the emerald it exists in a state of 
 green oxide, and the spiral ruby contains it in the iiate 
 of an acid. 
 
 Vanquelin extracted this metal from the red-le^d ore 
 by adding to it muriatic acid, which combines with the 
 oxide of lead, and forms a compound that is precipitated, 
 the chromic acid remaining in solution. To abstract a 
 little muriatic acid combined with it, oxide of silver i? 
 cautiously added, and the pure chromic acid, being de- 
 canted from the precipitate of muriate of silver, and 
 evaporated, is exposed to a very strong heat, excited 
 by a forge, in a crucible of charcoal, placed within 
 another of porcelain. It is thus reduced to the metallic 
 state. 
 
 Sulphuric acid decomposes the red-lead ore; btit it is 
 difficult to separate the products. Nitric acid does not 
 decompose this ore. 
 
 Chromic acid is very soluble in water: it is of an 
 orange-red colour, with a pungent metallic taste. By 
 evaporation, it affords crystals, in long slender prisms, of 
 a ruby-red colour. This acid combines with the alka- 
 lies, earths, and metallic oxides, and the neutral salts 
 which it forms with them are called chromates. 
 
 The combinations of this acid with metallic oxides are 
 in general possessed of very beautiful colours, and are 
 well adapted to the purposes of painting. That with 
 oxide of lead is an orange-yellow, of various shades 
 that with mercury, a vermilion-red ; with silver, a car- 
 mine-red ; with zinc and bismuth, the colours are yel 
 low ; with copper, cobalt, and antimony, they are dull. 
 
 The term chromium is derived from a Greek word 
 signifying colour, and is applied to this metal on account 
 of the diversity of colours which its compounds form. 
 
 The specific gravity of chromium, and the four follow 
 fog metals, is uncertain.
 
 15-1 CHEMISTRY. 
 
 COLUMBIUM. 
 
 A MINERAL in the British Museum, sent to Sir Harw 
 Sloane, with some iron, from Massachusetts, upon being 
 examined by Hatchett, was found to contain a new me. 
 tallic substance, to which that eminent chemist has given 
 the name of columbium. 
 
 The ore of columbium has never been perfectly re- 
 duced, but it affords an acid, called the columbic acid, 
 which differs from all other bodies. The alkalies throw 
 it down from its acid solutions, in white flakes. Prussiate 
 of potass changes the blue colour to an olive green, and 
 a precipitate of the same colour is gradually formed. 
 Tincture of galls produces a deep orange coloured precip- 
 itate. Zinc occasions a white precipitate. The fixed 
 alka-lies readily combine with the columbic acid. It is 
 insoluble and unalterable with regard to colour by the 
 nitric acid. 
 
 CERIUM. 
 
 CERIUM is another newly discovered metal, which 
 exists in a mineral called cerite. Cerite is semi-transpa- 
 rent, generally of a reddish colour, though occasionally 
 yellowish. Some specimens are hard enough to scratch 
 glass, and to strike fire with steel. To obtain the oxide 
 of cerium, this mineral is pulverized, calcined, and dissol- 
 ved in nitro-muriatic acid. The filtered solution, being 
 neutralized with potass, is to be precipitated by nitrate 
 of potass, and the precipitate, well washed, and after- 
 wards calcined, is oxide of cerium. This oxide is 
 susceptible of two degrees of oxidation ; in the first it is 
 white, and this by calcination becomes of a fallow red. 
 
 The white oxide of cerium, mixed with a large pro- 
 portion of borax, fuses into a transparent globule; but 
 in attempts to obtain the metallic cerium, the quantit/ 
 operated upon has always been so far dissipated, thai 
 the sensible properties of the metal are unknown
 
 OSMIUM. 1 55 
 
 IRIDIUM. 
 
 IJT a black powder, left after dissolving crude platina, 
 Tennant discovered two new metals, to one of which, he 
 gave the name of iridium. To analyze this powder, it 
 was mixed with pure dry soda, and kept at a red heat 
 for some time, in a silver crucible. The alkali was then 
 separated by solution in water, and the undissolved part 
 of the powder was digested with muriatic acid, with 
 which a solution, at first of a dark blue, was obtained; 
 it afterwards became of a dusky olive-green, and at last, 
 of a deep red. This acid solution contains two metals, 
 but chiefly iridium. By its evaporation, may be obtained 
 an imperfectly-crystallized mass, which, dissolved in wa- 
 ter, gives, by evaporation, distinct octahedral crystals. 
 These crystals, dissolved in water, produce a deep red 
 solution, inclining to orange. By exposure to heat, the 
 acid may be expelled ; but the indium thus produced 
 has never been fused, except by a powerful galvanic 
 battery. Its oxide, when obtained as above stated, is 
 white : it neither combines with sulphur nor ar;<cnic. 
 Lead unites with it easily, but is separated by cupelU- 
 tion, leaving the iridium on the cupel, in the form of a 
 coarse black powder. Copper and silver form with it 
 malleable alloys; but the iridium appears to be diffused 
 through the silver only in the state of a fine powder. 
 Gold remains malleable, although alloyed with a con- 
 siderable portion of it; and is not separated from it 
 either by cupellation or quartation. 
 
 OSMIUM. 
 
 THE metal found along with iridium, in the black 
 powder left after dissolving platina, is called osmium. 
 
 The oxide of osmium may be obtained by distilling 
 with nitre the black powder above-mentioned : at a low 
 red heat, an apparently oily fluid sublimes into the neck 
 of the retort, which, on cooling, concretes into a solid 
 colourless, semi-transparent mass. This, being dissolved
 
 156 CHEMISTRY. 
 
 in watei, forms a concentrated solution of oxide of os- 
 mium. This solution indelibly stains the skin of a deep 
 red or black. Infusion of galls renders the solution at 
 first purple, but in a little time, it becomes of a deep 
 vivid blue. If mercury be agitated with the solution, it 
 forms with the osmium a perfect amalgam. Part of the 
 mercury may be separated by squeezing it through 
 leather, and the rest by distillation, which will leave the 
 osmium pure, in the state of a black powder. This 
 powder has never been fused. It forms malleable al- 
 loys with copper and gold. 
 
 OF ACIDS. 
 
 ACIDS possess most or all of the following properties 
 
 1. They excite the sensation called sourness or acidity 
 
 2. They change the blue, green, and purple juices of 
 vegetables to red. 3. They combine with alkalies, earths 
 and metallic oxides ; with which they form compounds 
 called salts. 4. They combine with water in all pro 
 portions. 
 
 Most of the acids have been proved to contain oxvgen 
 as a component part ; and are more or less strong in pro- 
 portion as they are combined with more or less oxygen 
 They are not all, however, capable of combining with 
 more than one dose or proportion of oxygen : a few are 
 capable of combining with two doses of oxygen, and a 
 still smaller number with three. No acid has been ob- 
 tained by itself in combination with a fourth proportion 
 of oxygen. These differences it becomes necessary to 
 distinguish ; and the distinction is made in the following 
 manner. 
 
 When any body contains the smallest portion of oxy 
 gen, which converts it into an acid, the name of the base 
 or radical of the acid is terminated by ous ; thus, we 
 have the sulphurous acid. The next degree of oxygen- 
 isement is expressed by the termination ic ; thus, we 
 say, sulphuric acid. The third degree is expressed by 
 the addition of the word oxygenized, or its contraction,
 
 ACETIC ACID. 157 
 
 txy ; thus, we have the oxymuriatic acid. A fourth de- 
 gree of oxygenizement may be expressed by placing the 
 term hyper before that of oxy ; thus, we have hyper 
 oxymuriatic acid. There is only one instance of this 
 last mode of expression being necessary, and that instance 
 only refers to the acid as it is supposed to exist in com- 
 bination with another body. 
 
 ACERIC ACID. 
 
 A PECULIAR acid, said to exist in the juice of the ma- 
 ple. It is decomposed by heat, like the other vegetable 
 acids. 
 
 ACETIC ACID. 
 
 ACETIC acid may be obtained from crystallized acetate 
 ol copper, which must be reduced to powder, and dis- 
 tilled. A fluid, possessing little acidity, first rises, and 
 afterwards, a powerful acid. This acid has a greenish 
 hue when first prepared, because a small part of the 
 oxide of copper comes over with it ; but it may be ob- 
 tained, perfectly colourless, by distilling it with a gentle 
 heat. It may also be prepared, with more certainty as 
 to its freedom from copper, by distilling acetate of soda 
 or acetate of potass, with half its weight of sulphuric 
 acid. 
 
 Acetic acid is sold under the name of radical vinegar. 
 It is colourless like water : its smell is extremely pun- 
 gent, and its taste acrid. When applied to the skin, it 
 reddens and corrodes it. It is extremely volatile, wholly 
 evaporating on exposure to the air: and, when heated 
 in the open air, it takes fire readily. At 50, it freezes. 
 It unites with water in any proportion ; and on mixture 
 with it, heat is evolved. It dissolves camphor; and, 
 with the addition of essential oils, forms the aromatic 
 vinegar. 
 
 Acetic acid is used for smelling at ; crystals of sulphate 
 of potass being put into a bottle, and moistened with it 
 for that purpose. This mixture is called volatile salt of 
 11
 
 158 CHEMISTRY. 
 
 vinegar. A few drops of sulphuric acid, added to a 
 phial of the acetate of potass, make a strong smelling 
 bottle by the evolutions of the acetic acid. 
 
 Acetic acid may be advantageously employed to sepa 
 rate manganese from iron. When both metals are dis 
 solved in this acid, and the solution is evaporated to dry- 
 ness, the acid adheres to the manganese, but abandons 
 the iron. Water will then dissolve the acetate of man- 
 ganese from the oxide of iron. Two or three evapora 
 tions and solutions are sufficient to remove the whole of 
 its iron. 
 
 Acetic acid consists of oxygen, hydrogen, and carbon 
 but the proportions of its component parts have not been 
 clearly proved ; with various bases, it forms the salts 
 called acetates. 
 
 BENZ01C ACID. 
 
 THIS acid is obtained from the resin called benzoin or 
 benjamin, which is brought from the East Indies. By a 
 gentle heat the resin is sublimed, and condenses in the 
 form of long needles, or straight filaments of a white 
 colour, crossing each other in all directions. These are 
 what are sold under the name of flowers of benjamin, 
 and consist of the acid in question. When pure, they 
 are of a brilliant white, have an aromatic odour, are 
 entirely soluble in alcohol, but the addition of water 
 causes a precipitate. Hot water dissolves them copi- 
 ously, but cold water scarcely at all. They are not 
 altered by the air ; their taste is acrid and bitter. They 
 form a kind of paste if rubbed in a mortar. 
 
 The purest benzoic acid may be obtained in the 
 'humid way, by boiling the resin with carbonate of soda, 
 *nd adding diluted sulphuric acid to the filtered decoc- 
 tion as long as it produces any precipitation. The pre- 
 cipitate is the benzoic acid. 
 
 Benzoic acid is so inflammable, that it burns with a 
 clear yellow flame, without the assistance of a wick. 
 The mineral acids dissolve it, but it separates from them 
 without alteration, by the addition of water. It dissolves
 
 ARSENIOUS ACID. 159 
 
 in oils, and melted tallow. It unites with earthy and 
 alkaline bases, forming the salts called benzoates. 
 
 AMNIOTIC ACID. 
 
 A PECULIAR acid found in the liquor of the amnois of 
 the cow. It exists in the form of a white pulverulent 
 powder. It is slightly acid to the taste, hut sensibly 
 reddens vegetable blues. It is with difficulty soluble m 
 cold, but readily soluble in boiling water, and in alcohol. 
 When exposed to a strong heat, it exhales an odour of 
 ammonia and of prussic acid. Assisted by heat, it decom- 
 poses carbonate of potassa, soda, and ammonia. It pro- 
 duces no change in the solutions of silver, lead, or mer- 
 cury, in nitric acid. Amniotic acid may be obtained by 
 evaporating the liquor of the amnois of the cow to a 
 fourth part, and suffering it to cool ; crystals of amhiotic 
 acid will be obtained in considerable quantity. Whether 
 this acid exists in the liquor of the amnois of other ani- 
 mals, is not yet known. 
 
 ARSENIOUS ACID. 
 
 THIS is nothing more than the white oxide of arsenic 
 sold from the stores, without any preparation. It has a 
 weakly acid taste, and sensibly reddens the tincture of 
 cabbage and litmus, and most other vegetable blues ; the 
 syrup of violets, which it turns green, is an exception. 
 If thrown on burning coals, or a red-hot iron, it is vola- 
 tilized in the form of a white vapour, which emits the 
 smell of garlic. By a strong heat it is vitrified into a 
 transparent glass. It only contains about seven per cent 
 of oxygen. 
 
 Arsenious acid is soluble in 15 times its weight of boil~ 
 ing water, but requires for its solution eighty times its 
 weight of cold water. The solution crystallizes best by 
 glow evaporation ; it is very acrid ; it unites with the 
 p^i'th bases, decomposes the alkaline sulphurets, and 
 with them a yellow precipitate, in which the 
 approaches to the metallic state.
 
 160 CHEMISTRY. 
 
 The combinations of arsenious acid with different bases 
 re called arsenites. 
 
 BORACIC ACID. 
 
 BORACIC acid is procured from the salt called borax, in 
 the following manner: the borax is dissolved in hot 
 water, and the solution filtered ; sulphuric acid is added 
 very gradually to the solution, till it has a sensibly acU* 
 taste ; being then left to cool, a number of small, shining 
 laminated crystals form in it ; these crystals are th 
 boracic acid ; they are to be washed with cold water, 
 and dried upon brown paper. 
 
 The crystals of boracic acid are thin irregular hexa- 
 gons, of a silvery whiteness. They are soft and unctuous 
 to the touch, almost like spermaceti. They have no 
 smell, but a bitterish taste, with a slight degree of acidity ; 
 and they are unalterable in the air. When mixed with 
 spirit of wine, they cause it to burn with a green flame. 
 When sulphuric acid is poured upon them, a transient 
 odour of musk is perceived. 
 
 Boracic acid, when exposed to a violent fire, is converted 
 into a transparent glass ; this glass is soluble in water, 
 and the acid is again produced from evaporation. 
 
 It is much employed in analyzing minerals, as it brings 
 almost all the stones into solution. 
 
 BUTYRIC ACID. 
 
 WE owe the discovery of this acid to M. Chevreul. 
 Butter, he says, is composed of two fat bodies, analogous 
 to those of hogs' lard, of a colouring principle, and a 
 remarkably odorous one, to which it owes the properties 
 that distinguish it from the fats, properly so called. This 
 principle, which he has called butvric acid, forms well 
 characterized salts with barvtes, strontian, lime, the 
 oxides of copper, lead, &c. ; 100 parts of it neutralize 
 a quantity of base which contains 10 of oxygen. M. 
 Chevreul has not explained his method of separating 
 this acid from the other constituents of butter.
 
 CAMPHORIC ACID, CARBONIC ACID. 161 
 
 CAMPHORIC ACID. 
 
 CAMPHOR is a concrete essential oil, of a strong taste 
 and smell ; it is extracted by sublimation from a species 
 of laurel in the East Indies, and has a crystalline form. 
 It is so volatile, that it cannot be melted in open vessels, 
 and so imflammable, that it burns even on the surface of 
 water. Kosegarten, by distilling nitric acid eight times 
 successively from this substance, obtained an acid in 
 crystals, which is called camphoric acid. 
 
 Camphoric acid is in snow-vvhitj crystals, which efflo- 
 resce in the air. It has a slightly acid, bitter taste, and 
 a smell like saffron. It reddens vegetable blues. It re- 
 ' quires 200 times its weight of cold water to dissolve it ; 
 but boiling water takes up one-twelfth. If thrown upon 
 burning coals, it is entirely dissipated in a thick aromatic 
 smoke. With a gentle heat it melts and is sublimed. 
 It is soluble in alcohol, and not precipitated from it by 
 the addition of water, a property which distinguishes it 
 from the benzoic acid. It does not precipitate lime from 
 lime-water. 
 
 The mineral acids dissolve camphoric acid entirely, it 
 is also dissolved by the fixed and volatile oils. It unites 
 readily with the earths and alkalies, forming the salts 
 called camphorates. 
 
 CARBONIC ACID. 
 
 CARBONIC acid gas is the result of the combustion of 
 carbon. Every 100 parts of it, according to Tennant, 
 contain 18 parts of carbon and 82 of oxygen. Its 
 weight is to atmospheric air as 1500 to 1000. It has no 
 smell ; is invisible and elastic, like common air, but 
 extinguishes flame, and is totally unfit for respiration. 
 
 Carbonic acid is contained in the air to the amount ol' 
 about one part in the thousand. It is absorbed by water 
 if agitated, or long in contact with it. Strong pressure 
 will cause the water to absorb three times its bulk of 
 this gas, which imparts to it a taste agreeably acidulous 
 14* L
 
 162 CHEMISTRY. 
 
 and causes it to have a sparkling lustre when poured 
 from one vessel to another. The Pyrmont, Spa, and 
 Seltzer waters, are neutral combinations of carbonic 
 acid with water, and they can be imitated by art witr 
 the greatest precision. 
 
 The specific gravity of water saturated with carbonic 
 acid is 1.0015. If water containing carbonic acid be 
 frozen, the whole of this gas separates in freezing, and, 
 therefore, ice is never found to contain any. A boiling 
 heat also produces this separation. 
 
 Carbonic acid, frorq its gravity, may be poured from 
 one vessel to another, but if a portion of it be left in an 
 open vessel, for any length of time, it will be found to 
 have escaped ; the air having an attraction for it, gradu- 
 ally absorbs it, and will even abstract it nxiu water. 
 
 Carbonic acid exists in incalculable cuant.ties, com- 
 bined with other substances. Marble limestone, and 
 chalk consist of it in combination wth lime : it forms 
 about one-third of their weight, and m;iy be disengaged 
 from any of these substances, by means of an acid, or 
 considerable heat. The former means is generally more 
 convenient, when a quantity is required for the purpose 
 of experiment. The sulphuric acid, diluted with about 
 six times its weight of water, is poured upon the marble, 
 chalk, or limestone, previously reduced to a powder. An 
 effervescence immediately ensues : this is occasioned by 
 the extrication of carbonic acid gas, which must be col- 
 lected by means of the pneumatic apparatus. The mer- 
 curial trough should be used, if the gas is not intended 
 for immediate use. 
 
 Alcohol, and spirit of turpentine, absorb double their 
 weight of carbonic acid gas; olive oil, its own bulk. 
 Ether mixes with it in the state of gas. 
 
 Carbonic acid enters into combination with alkalies, 
 alkaline earths, alumine, zircon, and metallic oxides, 
 with which it forms salts called carbonates. 
 
 Water, impregnated with carbonic acid, and applied 
 to the roots of plants, is highly favourable to vegetation , 
 but, if this gas be applied to the leaves, as an atmo- 
 sphere, it is injurious.
 
 CASE1C ACID, CHLORIC ACID. 163 
 
 CASEIC ACID. 
 
 THE name given by Proust to an acid formed ir 
 cheeses, to which he ascribes their flavour. 
 
 CHLORIC ACID. 
 
 THIS acid was first eliminated from salts contain 
 ing it by Gay Lussac, and described by him, in his ad 
 mirable memoir on iodine. When a current of chlorine 
 is passed for some time through a solution of barytic 
 earth, in warm water, a substance called hyper-oxy- 
 muriate of barytes, by its first discoverer, Chenevix, is 
 formed, as well as some common muriate. The latter 
 is separated, by boiling phosphate of silver in the com- 
 pound solution. The former may then be obtained by 
 evaporation, in fine rhomboidal prisms. Into a diluted 
 solution of this salt, Gay Lussac poured weak sulphuric 
 acid. Though he added only a few drops of acid, not 
 nearly enough to saturate the barytes, the liquid became 
 sensibly acid, and not a bubble of oxygen escaped. By 
 continuing to add sulphuric acid with caution, he suc- 
 ceeded in obtaining an acid liquid, entirely free from 
 sulphuric acid and barytes, and not precipitating nitrate 
 of silver. It was chloric acid dissolved in water. 
 
 This acid has no sensible smell. Its solution in water 
 is perfectly colourless. Its taste is very acid, and it red- 
 dens litmus without destroying the colour. It produces 
 no alteration on solution of indigo in sulphuric acid. Light 
 does not decompose it. It may be concentrated by a 
 gentle heat, without undergoing decomposition, or with- 
 out evaporating. It was kept a long time exposed to the 
 air without sensible diminution of its quantity. When 
 concentrated it has something of an oily consistency. 
 When exposed to heat, it is partly decomposed into 
 oxygen and chlorine, and partly volatilized without 
 alteration. Muriatic acid decomposes it in the same 
 way, at the common temperature. Sulphurous acid, and 
 sulphuretted hydrogen, have the same property; but
 
 164 CHEMISTRY. 
 
 nitric acid produces no change upon it. Combined with 
 ammonia, it forms a fulminating salt. It does not pre- 
 cipitate any metallic solution. It readily dissolves zinc 
 disengaging hydrogen ; but it acts slowly on mercury. It 
 cannot be obtained in the gaseous state. Its taste is not 
 only acid but astringent, and its colour, when concentra- 
 ted, is somewhat pungent. 
 
 Chloric acid combines with the bases, and forms the 
 chlorates, a set of salts formerly known by the name of 
 hyper-oxygenated muriates. 
 
 CHLORIODIC ACID. 
 
 SIR H. DAVY formed it, by admitting chlorine in excess 
 to known quantities of iodine, in vessels exhausted of air, 
 and repeatedly heating the sublimate. Operating in tins 
 way, he found that iodine absorbs less than one-third of 
 its weight of chlorine. 
 
 Chloriodic acid, a very volatile substance, formed by 
 the sublimation of iodine in a great excess of chlorine, 
 is of a bright yellow colour ; when fused it becomes of a 
 deep orange, and when rendered elastic, it forms a deep 
 orange coloured gas. It is capable of combining with 
 much iodine when they are heated together ; its colour 
 becomes, in consequence, deeper, and the chloriodic acid 
 and the iodine rise together in the elastic state. The 
 solution of the chloriodic acid in water, likewise dissolves 
 large quantities of iodine, so that it is possible to obtain 
 a fluid containing very different proportions of iodine and 
 chlorine. 
 
 When two bodies so similar in their characters, and in 
 the compounds they form, as iodine and chlorine, act 
 upon substances at the same time, it is difficult, Sir H. 
 Davy observes, to form a judgment of the different parts 
 they play in the new chemical arrangement produced. 
 It appears most probable, that the acid property of the 
 chloriodic compound depends upon the combination of the 
 two bodies ; and its action upon solutions of the alkalies 
 and the earths may be easily explained, when it i* cor
 
 CHROMIC ACID, CITRIC ACID. 165 
 
 gidered that chlorine has a greater tendency than iodine 
 io form double compounds with the metals, that iodine 
 has a greater tendency than chlorine to form triple 
 compounds with oxygen and the metals. 
 
 A triple compound of this kind with sodium may exist 
 in sea- water, and would be separated with the first crys- 
 tals that are formed by its evaporation. Hence, it maj 
 exist in common salt. Sir H. Davy ascertained by feeding 
 birds with bread soaked with water, holding some of il 
 in solution, that it is not poisonous like iodine itself. 
 
 CHROMIC ACID. 
 
 This acid is furnished by the mineral called the red 
 lead ore of Siberia, which is a chromate of lead, and 
 from which chromium is obtained. It also exists in the 
 chromate of iron, which is more common than the former 
 mineral, and in France is even abundant. 
 
 The acid is extracted from the real lead ore of Siberia, 
 by boiling 100 parts of this mineral, with 300 of carbo- 
 nate of potass, and 400 of water, and separating the 
 alkali by means of weak nitric acid. It is an orange 
 coloured powder, which has an acrid, metallic taste, is 
 soluble in water, and crystallizable. If exposed to the 
 action of light and heat, this powder loses oxygen and 
 its acid properties, and is converted into the green oxide 
 of chromium. 
 
 If the muriatic acid be distilled upon the chromic acid, 
 it is oxygenized, and if simply mixed with the chromic 
 acid, the same effect takes place, for it acquires the 
 property of dissolving gold. This arises from the readi- 
 ness with which chromic acid parts with its oxygen. 
 
 Chromic acid unites readily with alkalies. It also 
 unites with borax, glass, and phosphoric acid, to which 
 it communicates an emerald green colour. 
 
 CITRIC ACID. 
 
 THE citric acid is found in the juice of lemons, oranges, 
 unripe grapes, and some other fruits. It is extremely
 
 1 66 CHEMISTRY. 
 
 acid to the taste, crystallizable, and very soluble in 
 water : cold water dissolves rather more than its own 
 weight of it, and hot water double its weight The 
 solution undergoes a spontaneous decomposition by long 
 keeping. 
 
 If lemon juice be exposed in an open vessel, it deposits 
 a quantity of mucilage, from which it may be separated 
 by decantation and filteration. If the juice thus purified, 
 be exposed to a freezing temperature, and the ice formed 
 in it, which consists only of its aqueous particles, be re- 
 moved as it is formed, the lemon juice will be obtained 
 in a state of high concentration. Its quantity will be 
 only about one-eighth of what it was at first, but its 
 strength will be eight times greater. It may be kept for 
 use, or may be made into dry lemonade, by adding six 
 times its weight of fine loaf-sugar in powder. 
 
 The lemon juice, prepared as above, is not pure citric 
 acid, but it retains a flavour which renders it better for 
 domestic use than if it were pure. To prepare pure 
 citric acid, Scheele saturated lemon-juice with lime, 
 edulcorated the precipitate, which consisted of citric 
 acid and lime, separated the lime from it by diluted 
 sulphuric acid, cleared it from the sulphate of lime by 
 repeated filterations and evaporations; then evaporated 
 it to the consistence of a syrup, and set it in a cool place : 
 a quantity of crystals formed which were pure citric acid. 
 Like the oxalic acid, it possesses the property of speedily 
 dissolving the oxides of iron. The dyers make use of it, 
 for no other acid can be employed with so much success 
 in enlivening the colours given by saffron : it appears 
 also that it will form with granitin, a liquor which with 
 cochineal, produces a scarlet colour superior to the usual 
 dye, especially with silk and morocco leather. Citric 
 acid whitens and hardens tallow, but as tartaric acid acts 
 nearly as well in this respect, and is considerably cheap- 
 er, it is seldom made use of for this purpose. 
 
 Citric acid oxidizes iron, zinc, and tin. It does not act 
 upon gold, silver, platina, mercury, bismuth, antimony 
 or arsenic.
 
 COLUMBIC ACID, DELPHINIC ACID. 167 
 
 The combinations of the citric acid with the different 
 bases, are called citrates. 
 
 COLUMBIC ACID 
 
 THE experiments of Hatchett have proved that a pe 
 cuiiar mineral, found in Massachusetts, deposited in the 
 British Museum, consisted of one part of oxide of iron, 
 and somewhat more than three of a white coloured sub- 
 stance, possessing the properties of an acid. Its basis 
 was metallic. Hence, he named this columbium, and 
 the acid, the columbic. Dr. Wollaston, by very exact 
 analytical comparisons, proved that the acid of Hatchett 
 was the oxide of the metal lately discovered in Sweden 
 by Ekeberg, in the mineral ytrotantalite, and thence 
 called tantalum. Dr. VVollaston's method of separating 
 the acid from the mineral is peculiarlv elegant. One 
 part of tantalite, five parts of carbonate of potassa, and 
 two parts of borax, are fused together in a platina cru- 
 cible. The mass, after being softened in water, is acted 
 on by muriatic acid. The iron and manganese dissolve, 
 while the columbic acid remains at the bottom. It is in 
 the form of a white powder, which is insoluble in nitric 
 and sulphuric acids, but partially in muriatic. It forms, 
 with barytes, an insoluble salt, of which the proportions, 
 according to Berzelius, are 24.4 acid, and 9.70 barytes. 
 By oxidizing a portion of the tantalum or columbium, 
 Berzelius concludes the composition of the acid to be 
 100 metal, and 5.485 oxygen. 
 
 DELPHINIC ACID. 
 
 THE name of an acid extracted from the oil of the dol- 
 ohin. It resembles a volatile oil ; has a light lemon 
 colour, and a strong aromatic odour, analogous to that 
 of rancid butter. Its taste is pungent, and its vapour has 
 a sweetened taste of ether. It is slightly soluble in 
 water, and very soluble in alcohol The latter solution 
 strongly reddens litmus. 100 parts of delphinic acid
 
 168 CHEMISTRY. 
 
 neutralize a quantity of base which contains 9 of oxy 
 gen; whence, its prime equivalent appears to be 11.11. 
 
 ELLAGIC ACID. 
 
 So named by Braconnet, by reversing the word galle, 
 The deposit, which forms in infusion of nut-galls left to 
 itself, is not composed solely of gallic acid, and a matter 
 which colours it. It contains, beside a little gallate and 
 sulphate of lime, and a new acid, which was pointed out 
 by Chevreuil, in 1815. an acid on which Braconnet made 
 observations in 1818, and which he proposed to call acid 
 ellagic, from the word galle, reversed. Probably thi: 
 acid does not exist ready formed in nut-galls. It is in 
 soluble ; and, carrying down with it the greater part of 
 the gallic acid, forms the yellowish crystalline deposit 
 But boiling water removes the gallic acid from the ella 
 gic ; whence, the means of separating them one from 
 another. 
 
 It has a pale yellow lemon colour, but no smell. Heat 
 and light decompose it. Hydroeganic acid is then formed, 
 and white ferro-prussiate of iron, which soon becomes 
 blue. Its affinity for the bases enables it to displace acetic 
 acid, without heat, from the acetates, and to form ferro- 
 prussiates. 
 
 FLUORIC ACID. 
 
 THIS acid is contained in the mineral called fluor or 
 fusible spar, which consists of fluoric acid and lime. If 
 sulphuric acid be poured upon this spar in powder, the 
 lime combines with it to form sulphate of lirne, and the 
 fluoric acid is expelled, and they may be collected by the 
 pneumatic apparatus. The sulphuric acid should be 
 well concentrated, and equal in weight to the fluor spar. 
 A leaden retort must be used in the distillation, and 
 only a gentle heat will be required. The gas should be 
 eceived over mercury. 
 
 Fluoric acid gas is invisible and elastic like common 
 air; it will not maintain combustion, and cannot be
 
 FLUORIC ACID. 169 
 
 breathed without causing death. It has the odour ol 
 muriatic acid, but is more corrosive, and when exposed 
 to a moist atmosphere, it becomes cloudy. 
 
 Fluoric acid gas is heavier than common air. It cor- 
 rodes the skin almost instantly. It combines rapidly 
 with water, with which it forms liquid fluoric acid ; as it 
 dissolves silex, it cannot be prepared in glass vessels, nor 
 kept in them, unless they be lined internally with wax 
 or some similar coating. The acid combines with the 
 silex of glass, and the silex passes over with it in the 
 distillation. It is for this reason that it is usually kept 
 as well as prepared in leaden or tin bottles. It is absorb- 
 ed by alcohol and ether without altering their qualities : 
 water impregnated with it must be pooled down to 23 
 before it will freeze. 
 
 The action of fluoric acid, upon all inflammable sub- 
 stances, is, in general, very feeble. 
 
 It will oxidize iron, zinc, copper, and arsenic ; but 
 has no action upon platina, gold, silver, lead, tin, anti- 
 mony, cobalt, mercury. 
 
 It combines with alkalies, alkaline earths, alumine, 
 and metallic oxides; and forms the salts called fluates. 
 
 Fluoric acid has been discovered in the enamel of 
 the human teeth, and in ivory. Vanquelin also found it 
 in topaz. 
 
 The only use to which fluoric acid has been applied, 
 is that of etching upon glass. For this purpose, either 
 the liquid fluoric acid may be employed, or the gas. If 
 the former, the glass remains polished where the acid 
 has corroded ; but with the gas, the lines have the ap- 
 pearance as if the glass had been ground, and not polished. 
 Landscapes, and other designs, properly executed upon 
 glass, by means of this acid, have an elegant appear 
 ance. The process is the same as that for etching upon 
 copper, except that so much care is not necessary in pre- 
 paring the ground : bees'-wax alone will suffice. 
 
 15
 
 170 CHEMISTRY. 
 
 GALLIC ACID. 
 
 THIS acid is found in the nut-galls, and generally, ir- 
 al! astringent vegetables, though it exists independent!) 
 of the astringent principle. The nut-gall is an excres- 
 cence produced on a species of oak, by the puncture of 
 an insect 
 
 The gallic acid may be obtained by various processes : 
 the following method is proposed by Proust. Pour a 
 solution of the muriate of tin into an infusion of nut-galls 
 a copious yellow precipitate is instantly formed, consist- 
 ing of the tanning principle, combined with the oxide of 
 tin. After diluting the liquor with a sufficient quantity 
 of water to separate any portion of this precipitate which 
 the acids might hold in solution, the precipitate is to be 
 separated by Alteration. The liquid contains gallic acid, 
 muriatic acid, and muriate of tin. To separate the tin, 
 a quantity of the sulphuretted hydrogen gas is to be 
 mixed with the liquid. Sulphuret of oxide of tin is pre- 
 cipitated under the form of a brown powder. The liquid 
 is then to be exposed for some days to the light, covered 
 with paper, till the superfluous sulphuretted hydrogen 
 gas exhales. After this, it is to be evaporated to the 
 proper degree of concentration, and left to cool. Crys- 
 tals of gallic acid are deposited : these are to be sepa- 
 rated by tilteralion, and washed with cold water. The 
 evaporation of the rest of the liquid is to be repeated, till 
 all the gallic acid is obtained from it 
 
 The gallic acid thus obtained has a very acid taste ; 
 it reddens vegetable blues, dissolves in l parts of boil- 
 ing water, and 12 parts of cold water. Alcohol dissolves 
 one-fourth of its weight in the cold, and its own weight, 
 if assisted by heat. 
 
 Gallic acid thrown upon burning coals, inflames, and 
 emits an aromatic odour, not very dissimilar to that of 
 the benzoic acid. Its residuum is charcoal. It is decom- 
 posed by distillation. It has a great affinity for most of 
 the metallic oxides, which it will take from the strongest 
 acids. A solution of gold it renders green, and causes a
 
 HYDRIODIC ACID, IODIC ACID. 171 
 
 Drown precipitate, which readily passes to the metallic 
 state. On the nitric solution of silver, it has the same 
 effect. Mercury, it precipitates of an orange-yellow ; 
 copper, brown ; bismuth, of a lemon colour ; lead, white ; 
 iron, purple, or black ; for which reason, nut-galls are 
 used to form writing-ink : they are also extensively used 
 in dyeing. Platina, zinc, tin, cobalt, and manganese, it 
 does not precipitate. 
 
 The combination of the gallic acid with the different 
 bases, are called gallates. 
 
 HYDRIODIC ACID. 
 
 A GASEOUS acid in its insulated state. If 4 parts of 
 iodine be mixed with one of phosphorus, in a small glass 
 retort applying a gentle heat, and adding a few drops of 
 water from time to time, a gas comes over, which must 
 be received in the mercurial bath. It is elastic and 
 invisible, but has a smell somewhat similar to that of 
 muriatic acid. Mercury after some time decomposes it, 
 seizing its iodine, and leaving its hydrogen, equal to one 
 half the original bulk, at liberty. Chlorine, on the other 
 hand, unites to its hydrogen, and precipitates the iodine. 
 From these experiments, it evidently consists of vapour 
 of iodine and hydrogen, which combine in equal volumes, 
 without change of their primitive bulk. Hvdriodic acid 
 is partly decomposed at a red heat, and the decomposition 
 is complete if it be mixed with oxygen. Water is form- 
 ed and iodine separated. 
 
 IODIC ACID. 
 
 WHEN barytes water is made to act on iodine, a 
 soluble hydriodate, and an insoluble iodate of barytes, 
 are formed. On the latter well washed, pour sulphuric 
 acid equivalent to the barytes present, diluted with twice 
 its weight of water, and heat the mixture. The iodic 
 acid quickly abandons a portion of its base, and com- 
 bines with the water; but though even less than the
 
 
 172 CHEMISTRY. 
 
 equivalent proportion of sulphuric acid has been used, a 
 little of it will be found mixed with the liquid acid. Il 
 we endeavour to separate this portion, by adding baiytes 
 water, the two acids precipitate together. 
 
 LACCIC ACID. 
 
 THIS --tcid is obtained from lacca, the substance in 
 which it exists. Dr. Sohn made a watery extract of 
 powdered sticklac, and evaporated it to dryness. He 
 digested alcohol on this extract, and evaporated the alco- 
 holic extract to dryness. He then digested this mass in 
 ether, and evaporated the ethereal solution ; when he 
 obtained a syrup mass of a light yellow colour, which 
 was again dissolved in alcohol. On adding water to this 
 solution, a little resin fell. A peculiar acid united to 
 potassa and lime remains in the solution, which is ob- 
 tained free, by forming with acetate of lead an insoluble 
 laccate, and decomposing this with the equivalent quan- 
 tity of sulphuric acid. Laccic acid crystallizes; it has a 
 wine yellow colour, a sour taste, and is x soluble as we 
 have seen, in water, alcohol, and ether. It precipitates 
 lead and mercury white, but it does not affect lime, 
 barytes, or silver in their solutions. It throws down the 
 salts of iron white. With lime, potassa, or soda, it forms 
 deliquescent salts, soluble in alcohol. 
 
 LACTIC ACID. 
 
 
 THIS is the acid which appears in milk, that has be- 
 come sour. To obtain it by Scheele's process, evaporate 
 a quantity of sour whey to an eighth part, and then filter 
 it; this separates the cheesy part. Saturate the liquid 
 with lime-water, and the phosphate of lime precipitates. 
 Filter again, and dilute the liquid with three times its 
 own bulk of water; add to it oxalic acid, drop by drop, 
 to precipitate the lime which has dissolved from the lime- 
 water ; then add a very small quantity of lime-water, to 
 see whether too much oxalic acid has been added. If
 
 
 LITHIC OR URIC ACID, MALIC ACID. 173 
 
 there has, oxalate of lime immediately precipitates. 
 Evaporate the solution to the consistence of honey, pour 
 in a sufficient quantity of alcohol, and filter again ; the 
 acid passes through dissolved in the alcohol, but the 
 sugar of milk, and every other substance, remains behind. 
 Add to the solution a small quantity of water, and distil 
 ivith a low heat ; the alcohol passes over, and leaves 
 oehind the lactic acid dissolved in water. 
 
 Lactic acid is incapable of crystallizing; when evapo- 
 rated to dryness, it deliquesces in the air. Its salts are 
 called lactates. 
 
 LITHIC OR URIC ACID. 
 
 SCHEELE, in analyzing human calculi, found that a 
 peculiar acid constituted a greater part of them all, and 
 nearly the whole of some. It exists in human urine, 
 from which it spontaneously separates in a few days in 
 the form of red crystals with brilliant facets, the urine 
 at the same time losing its colour and acjd nature. It 
 has neither taste nor smell, but reddens vegetable blues. 
 It is soluble in 2000 times its weight of cold water. It 
 is a composition of carbon, nitrogen, hydrogen, and 
 oxygen. 
 
 This acid is found in the urine of the camel, and in 
 those anthritic concretions commonly called chalk-stones. 
 
 MALIC ACID. 
 
 THIS acid is obtained by saturating the juice of apples 
 with alkali, pouring in the acetous solution of lead, 
 until it occasions no more precipitate. The precipitate 
 s then to be edulcorated, and sulphuric acid poured on 
 it, until the liquor has acquired a fresh acid taste, with- 
 out any mixture of sweetness. The whole is then to be 
 filtered, to separate the sulphate of lead. The filtered 
 liquor is the malic acid, which is very pure, remains 
 always in a fluid state, and cannot be rendered concrete 
 15*
 
 174 CHEMISTRY. 
 
 MARGARITIC ACID. 
 
 WHEN we immerse soap, made of pork-grease air! 
 potassa, in a large quantity of water, one part is dissolved, 
 while the other part is precipitated in the form of seve- 
 ral brilliant pellets. These are separated, dried, washed 
 in a large quantity of water, and then dried on a filter 
 they are now dissolved in boiling alcohol, specific gra- 
 vity 0.820; from which, as it cools, the pearly substance 
 falls down pure. On acting on this with diluted muriatic 
 acid, a substance of a peculiar kind, which Chevreuil, 
 the discoverer, calls margarine, or margaritic acid, is 
 separated. It must be well washed with water, dissolved 
 in boiling alcohol ; from which it is recovered, in the same 
 crystalline form, when the solution cools. 
 
 Margaric acid is pearly white, and tasteless. Its 
 smell is feeble, and a little similar to that of melted wax. 
 Its specific gravity is inferior to that of water. It melts 
 at 134 F., into a very limpid, colourless liquid, which 
 crystallizes, on cooling, into brilliant white needles, of 
 the finest white. It is insoluble in water, but very solu- 
 ble in alcohol, specific gravity 0.800. Cold margaric 
 acid has no action on the colour of litmus; but when 
 heated so as to soften without melting, the blue was red- 
 dened. It combines with the salifiable bases, and forms 
 neutral compounds. Two orders of margarites are 
 formed, the margarites, and the super-marga rites ; the 
 former being converted into the latter by pouring a large 
 quantity of water on them. Other fats, besides that of 
 the hog, yield this substance. 
 
 That of man is obtained under three different forms. 
 1. In very fine long needles, disposed in flat stars. 2. In 
 very fine and very short needles, forming waved figures, 
 like those of the margaric acid of carcases. 3. In very 
 large brilliant crystals, disposed in stars, similar to the 
 margaric acid of the hog. The margaric acids of man 
 and the hog resemble each other ; as do those of the ox 
 ind the sheep ; and of the goose and the jaguar. The 
 compounds with the bases, are real soap's. The solution 
 u alcohol affords the transparent soaps of this country
 
 MECONIC, MELASSIC, AND MELLITIC ACID. 175 
 
 MECONIC ACID. 
 
 THIS acid is a constituent of opium. It was discovered 
 Dy Sertuerner, who procured it in the following way : 
 Alter precipitating the morphia, from a solution oi 
 opium, by ammonia : he added to the residual fluid a 
 solution oi muriate of barytes. A precipitate is in this 
 way formed, which is supposed to be a quadruple com- 
 pound, of barytes, morphia extract, and the meconic 
 acid. The extract is removed by alcohol, and the 
 barytes by sulphuric acid; when the meconic acid is 
 left, merely in combination with a portion of the morphia- 
 from this it is purified by successive solutions and evapo- 
 rations. The acid, when sublimed, forms long colourless 
 needles ; it has a strong affinity for the oxide of iron, s( 
 as to take it from the muriatic solutions, and form with 
 it a cherry-red precipitate. It forms a crystal li/able 
 salt with lime, which is not decomposed by sulphuric 
 acid, and what is curious, it seems to possess no particu- 
 lar power over the human body, when received into the 
 stomach. The essential salt of opium, obtained in 
 Derosne's original experiments, was probably the mecc- 
 niate of morphia. 
 
 Robiquet has made a useful modification of the pro- 
 cess for extracting meconic acid. He treats the opium 
 with magnesia, to separate the morphia, while meconiate 
 of magnesia is also formed. The magnesia is removed 
 by adding muriate of barytes, and the barytes is after- 
 wards separated by dilute sulphuric acid. A larger pro- 
 portion of meconic acid is thus obtained. 
 
 MELASSIC ACID. 
 
 THE acid present in melasses, which has been thought 
 a peculiar acid by some, by others the acetic. 
 
 MELLITIC ACID. 
 
 KLAPROTH discovered in the mellilite, or honey stone, 
 what he conceives to be a peculiar acid of the vegetable
 
 1*?6 CHEMISTRY. 
 
 kind, cmnmned with alumina. This acid is easily obtained 
 by reducing the stone to powder, and boiling it in about 
 seventy times its weight of water ; when the acid will 
 dissolve, and may be separated from the alumina by 
 filteration. By evaporating the solution, it may be ob- 
 tained in the form of crystals. The following are ite 
 characters. - 
 
 It crystallizes in fine needles or globules by the union 
 of these, or small prisms. Its taste is at first a sweetish- 
 sour, which leaves a bitterness behind. On a plate of 
 hot metal it is easily decomposed, and dissipated in copi- 
 ous grey fumes, which affect not the smell, leaving 
 behind a small Quantity of ashes, that do not change 
 either led or blue tincture of litmus. Neutralized by 
 potassa, it crystallizes in groups of long prisms: by soda, 
 in cubes, or trianguhr laminae, sometimes in groups, some- 
 times single ; and be ammonia, in beautiful prisms with 
 six planes, which soon lose their transparency, and ac- 
 quire a silver-white hue. If the metallic acid be dissolved 
 in lime water, and a solution of calcined strontian or 
 barytes be dropped into it, a white precipitate is throvrn 
 down, which is re-dissolved on adding muriatic acid. 
 With a solution of acetate of barytes, it produces like- 
 wise a white precipitate, which nitric acid re-dissolves. 
 With a solution of muriate of barytes, it produces no 
 precipitate, r even cloud ; but after standing some time, 
 fine transparent needly crystals are deposited. The 
 metallic acid produces no change in a solution of nitrate 
 of silver. From a solution of nitrate of mercury, either 
 hot or cold, it throws down a copious white precipitate, 
 which an addition of nitric acid immediately re-dissolves. 
 With nitrate of iron it gives an abundant precipitate of 
 a dun yellow colour, which may be re-dissolved by muri- 
 atic acid. Wi!h a solution of acetate of lead, it produces 
 an abundant precipitate, immediately re-dissolved on 
 adding nitric acid. With acetate of copper, it gives a 
 greyish-green precipitate; but it does not effect a solu- 
 tion of muriate of copper. Lime-water precipitated by 
 t, is immediately re-dissolved on adding nitric acid.
 
 MENISPERMIC ACID, MOLYBD1C ACID. 177 
 
 MENISPERMIC ACID. 
 
 THE seeds of menispennune oculus, being macerated 
 for 24 hours, in 5 times their weight of water, first cold, 
 and then boiling hot, yield an infusion, from which solu- 
 tion, sub-acetate of lead throws down a menispermate 
 of lead. This is to be washed and drained, diffused 
 through water, and decomposed by a current of sulphu- 
 retted hydrogen gas. The liquid thus freed from lead, 
 is to be deprived of sulphuretted hydrogen by heat, and 
 then forms solution of menispermic acid. By repeated 
 evaporations and solutions in alcohol, it loses its bitter 
 taste, and becomes a purer acid. It occasions no precip- 
 itate with lime-water; with nitrate of barytes it yields a 
 grey precipitate ; with nitrate of silver, a deep yellow ; 
 and with sulphate of magnesia, a copious precipitate. 
 
 MOLYBDIC ACID. 
 
 MOLYBDIC acid is obtained from the ore or sulphuret 
 of molybdenum, by distilling nitric acid off it repeatedly, 
 till the sulphur and metal are both acidified, which is 
 known by the conversion of the whole into a white mass, 
 Hot water carries ofF the sulphuric acid, and leaves the 
 molvbdic acid in a state of purity. 
 
 Molybdic acid is a yellowish-white powder ; it has an 
 acrid but metallic taste. It is not altered in the air, and 
 will bear a strong heat if the crucible be covered ; but 
 if the crucible be uncovered, the acid rises in the form 
 of a white smoke. Its specific gravity is 3.75. It re 
 quires 570 times its weight ef water to dissolve it. The 
 solution has a sour taste, coagulates solutions of soap, and 
 precipitates alkaline sulphurets. Paper dipped in this 
 acid becomes of a beautiful blue colour in the sun. 
 
 The molvbdic acid has not been applied to any use in 
 the arts, though experiments have been made which indi 
 cate that it may become useful in dyeing. Its combina 
 tions with different bases are called molybdates. 
 
 M
 
 178 CHEMISTRY. 
 
 MOLYBDENOUS ACID. 
 
 MOLYBDEYA is susceptible of four different combinations 
 with oxygen ; at the lowest it is in a state of black oxide,- 
 at the next it is blue ; at the third it begins to assume 
 acid properties, and is green. This is thejnolybdenous 
 acid. The next dose of oxygen forms the yellowish 
 white powder, which is the acid treated of in the last 
 section. 
 
 MUCIC ACID. 
 
 THIS acid has been generally known by the name of 
 saccholactic, because it was first obtained from sugar of 
 milk ; but as all the gums appear to afford it, and the 
 principal acid in the sugar of milk is the oxalic, chemists, 
 in general, now distinguish it by the name of mucic acid. 
 
 It was discovered by Scheele. Having poured twelve 
 ounces of diluted nitric acid on four ounces of powdered 
 sugar of milk, in a glass retort on a sand bath, the mix- 
 ture became gradually hot, and at length effervesced 
 violently, and continued to do so for a considerable time 
 after the retort was taken from the fire. It is necessary 
 therefore, to use a large retort, and not to bite the 
 receiver too tight. The effervescence having nearly 
 subsided, the retort was again placed on the sand heat, 
 and the nitric acid distilled off, till the mass had acquired 
 a yellowish colour. This exhibiting n crystals, eight 
 ounces more of the same acid were added, and the 
 distillation repeated, till the yellow colour of the fluid 
 disappeared. As the fluid was inspissated by cooling, it 
 was re-dissolved in eight ounces of water, and filtered. 
 The filtered liquor held oxalic acid in solution, and seven 
 drachms and a half of white powder remained on the 
 filter. This powder was the acid under consideration. 
 
 If one part of gum be heated gently with two of nitric 
 acid, till a small quantity of nitrous gas and carbonic 
 acid is disengaged, the dissolved mass will deposit on 
 cooling the mucic acid. According to Fourcroy and 
 Vanquelin, different gums yield from 14 to 26 hundredths 
 of this acid.
 
 MURIATIC ACID. 179 
 
 This pulverulent acid is soluble in about sixty parts of 
 hot water, and by cooling, a fourth part separates in 
 small shining scales, that grow white in the air. It de- 
 composes the muriate of barytes, and both the nitrate 
 and muriate of lime. It acts very little on the metals, 
 b'lt forms with their oxides salts scarcely soluble. It 
 precipitates the nitrate of silver, lead, and mercury. 
 With potassa it forms a salt soluble in eight parts of 
 boiling water, and crystallizable by cooling. That of 
 soda requires but five parts of water, and is equally 
 crystallizable. Both these salts are still more soluble 
 when the acid is in excess. That of ammonia is deprived 
 of its base by heat. The salts of barytes, lime, and 
 magnesia are nearly insoluble. 
 
 MURIATIC ACID. 
 
 MURIATIC acid, so generally known under the name of 
 spirit of salt, or marine acid, is a combination of oxy 
 gen with an unknown base ; for the acid has never been 
 decomposed. 
 
 In its combinations it is very abundant in the mineral 
 kingdom, particularly with soda, lime, and magnesia. Its 
 combination with soda forms common salt, and the affinity 
 of the two substances, is such, that they are not separated 
 oy a heat which volatilizes salt. In obtaining this acid 
 from muriate of soda, therefore, some substances must 
 be used which will combine with the alkali. Sulphuric 
 acid, or substances which contain it, such as clay, are 
 generally used. Mix one part of sulphuric acid with 
 two parts of dry muriate of soda, in a glass retort, apply 
 a gentle heat, and use the mercurial pneumatic trough 
 to collect the product which comes over. The product 
 is muriatic acid in a state of gas. This gaseous acid is 
 invisible, and elastic, like common air, but has about 
 twice its specific gravity. It has a pungent, suffocating 
 gmell, and it is extremely caustic. 
 
 Muriatic acid gas absolves water with avidity. Water 
 will Combine with its weight of the gas, and the specific
 
 180 CHEMISTRY. 
 
 gravity of the liquid muriatic acid thus obtained is 1.5 
 it is, however, not easily procured and preserved of a 
 greater specific gravity than 1.190. 
 
 Liquid muriatic acid is generally of a pale yellow 
 colour, but this colour is attributed to the presence of 
 some impurity; it preserves the smell of the gas, is very 
 volatile, and gives out white fumes by exposure to thf 
 atmosphere. 
 
 It is capable, by the assistance of heat, of oxidizing 
 iron, tin, lead, zinc, bismuth, cobalt, nickel, manganese, 
 antimony, and arsenic. At a boiling heat, it oxidizes 
 silver and copper. On gold, platina, mercury, tungsten, 
 molybdenum, tellurium, arid titanium, it has no action. 
 
 The proper solvent for gold and platina, is the nitro- 
 muriatic acid, composed of one part of muriatic, and 
 two of nitric acid. 
 
 Muriatic acid is the best test for silver. A single drop 
 of it poured into a solution containing this metal will 
 cause a copious precipitate. 
 
 Muriatic acid, combined with different bases, forms the 
 salts called muriates. 
 
 This acid, in the state of gas, has a powerful effect in 
 neutralizing putrid effluvia. Morveau, by pouring two 
 pounds of sulphuric acid upon six pounds of common 
 salt, and having the mixture on a common house furnace 
 of live coal, completely destroyed the putrid exhalations 
 which had caused the cathedral of Dijon to be deserted. 
 
 NITRIC ACID. 
 
 NITRIC acid is formed by the chemical union of about 
 25 parts by weight of nitrogen, with 75 parts of oxygen. 
 By mixing nitrogen and oxygen in these proportions, 
 and passing a number of electrical shocks through the 
 mixture, nitric acid is produced. In other words, the 
 combustion of nitrogen produces nitric acid. 
 
 Nitric acid, combined with potass, form the salt called 
 nitrate of potass, or saltpetre, and it is by the decom- 
 position of this salt, that it may be procured. If three
 
 NITRIC ACID. 181 
 
 parts of nitrate of potass, with one of sulphuric acid, be 
 distilled, the nitric acid, mixed with a small proportion 
 of nitrous, comes over. The nitrous acid may he expel- 
 led by a gentle heat. Nitric acid is clear and colourless, 
 like water ; it corrodes animal substances, and stains the 
 human skin a permanent yellow. Its smell is remark- 
 ably pungent, and its taste strongly acid ; in short, it 
 eminently possesses all the properties enumerated as 
 peculiar to acids. The action of light alone will, how- 
 ever, separate a part of its oxygen, and cause it to 
 assume a yellow colour. 
 
 Nitric acid has a strong affinity for water, and has 
 never been obtained except in combination with it. 
 When concentrated, it attracts moisture from the atmo- 
 sphere, but not so powerfully as the sulphuric acid. 
 When mixed with water, it produces heat, but not in 
 equal degree with the sulphuric acid. It boils at 248. 
 When concentrated to the utmost, its specific gravity is 
 about 1 5. When diluted with water, it is sold under 
 the name of aquafortis : even the double aquafortis of 
 the stores sold is only about half the strength of nitric 
 acid. 
 
 Nitric acid is easily decomposed, and it therefore con- 
 stitutes a valuable agent to the chemist. It is capable 
 of oxidizing all the metals, except gold and titanium ; 
 and even gold it appears to attack in a slight degree. 
 If brought into contact with hydrogen at a slight tem- 
 perature, a violent detonation is produced. If mixed 
 with oils, it sets them on fire, and both the acid and the 
 oil is decomposed. The oils should -be free from water, 
 but as this is rarely the case, the experiment is most cer- 
 tain of success if a little sulphuric acid be mixed with 
 the nitric acid, as that acid will combine with the water. 
 Oils deprived of water by boiling, inflame with nitric 
 acid alone. In making these mixtures, the operator 
 bhould keep himself at a distance from them, by using 
 vessels with long handles. 
 
 Perfectly dry charcoal is also inflamed by nitric acid : 
 with dry filings of iron the same effect takes place ; and 
 16
 
 182 CHEMISTRY. 
 
 also with zinc, and tin, if the acid be poured upon then: 
 in fusion. 
 
 The nitric acid, with the alkalies, alkaline earths, alu 
 mine, zircon, and the oxides of metals, form the salti 
 called nitrates. 
 
 NITROUS ACID. 
 
 ACCORDING to the principles of the new nomenclature, 
 here is no acid strictly entitled to the appellation of ni- 
 trous acid : the acid which obtains this name is not the 
 acid of nitre with a minimum of oxygen, but nitric acid, 
 combined with different proportions of nitric oxide ; of 
 which an account will be found under the head of 
 oxides. 
 
 Nitrous acid is more or less coloured, according to the 
 quantity of nitric oxide with which it is impregnated. It 
 parts with the gas very readily; which, when in quan- 
 tity, passes off in vapours that assume a red colour on 
 mixing with the atmosphere. On account of the extri- 
 cation of these vapours, the acid is sometimes called 
 fuming aquafortis. The addition of different portions of 
 water causes nitrous acid to appear blue, green, yellow 
 &c. ; but the vapours are always of the same red hue. 
 
 The general properties of nitrous acid are similar to 
 those of the nitric ; with different bases, it forms the 
 salts called nitrates. These are not formed by the di- 
 rect union of their component parts ; but by exposing 
 nitrates to a high temperature, which, separating a part 
 of their oxygen, leaves them in the state of nitrates. 
 
 NITROLEUCIC ACID. 
 
 THIS acid is so named from its being obtained by the 
 action of nitric acid on leucine. Leucine is capable of 
 uniting to nitric acid, and forming a compound, which 
 Braconnet has called the nitroleucic acid. When we 
 dissolve leucine in nitric acid, and evaporate the solution 
 to a certain point, it passes into a crystalline mass, with- 
 Oit any disengagement of nitrous vapour, or of an^
 
 NITRO-MURIATIC, NITRO-SULPHURIC, OLE1C. 183 
 
 gaseous matter. If we press this mass between blotting- 
 paper, and dissolve it in water, we shall obtain from 
 this, by concentration, fine divergent, and nearly colour- 
 less needles. These constitute the new acid. It unites 
 to the bases, forming salts which fuse on red-hot coals. 
 The nitro-leucates of lime and magnesia are unalterable 
 in the air 
 
 NITRO-MURIATIC ACID. 
 
 Aqua regia. When nitric and muriatic acids are 
 mixed, they become yellow, and acquire the power of 
 readily dissolving gold, which neither of the acids pos- 
 sessed separately. This mixture evolves chlorine, a par- 
 tial decomposition of both acids having taken place ; and 
 water, chlorine, and nitrous acid gas are thus produced : 
 that is, the hydrogen of the muriatic acid abstracts oxy- 
 gen from the nitric, to form water. The result must be 
 chlorine and nitrous acid. 
 
 NITRO-SULPHURIC ACID. 
 
 A COMPOUND consisting of one part of nitre dissolved 
 in about ten of sulphuric acid. 
 
 OLEIC ACID. 
 
 WHEN potassa and hogs' lard are saponified, the mar- 
 garate of the alkali separates, in the form of a pearly- 
 looking solid, while the fluid fat remains in solution, 
 combined with the potassa. When the alkali is sepa- 
 rated by tartaric acid, the oily principle of fat is ob- 
 tained, which Chevreuil purifies by saponifying it again, 
 and again recovering it two or three times ; bv which 
 means the whole of the margarine is separated. As this 
 oil has the property of saturating bases, and forming 
 neutral compounds, he has called it oleic acid.
 
 * 
 
 184 CHEMISTRY. 
 
 OXALIC ACID. 
 
 THE oxalic acid exists in the juice of the wood-sorrel, 
 combined with potass. When prepared from this plant, 
 it is sold under the name of salt of lemons; and is used 
 as a substitute for the real juice of lemons. Sugar, and 
 all other saccharine substances, contain the radical of 
 the very same acid which wood-sorrel affords. It may 
 be extracted from sugar in the following manner : 
 
 To six ounces of nitric acid, in a tubulated retort, t 
 which a large receiver is luted, add, by degrees, one 
 ounce of lump sugar, coarsely powdered. A gentle heat 
 may be applied during the solution, and nitric oxide will 
 be evolved in abundance. .When the whole of the 
 sugar is dissolved, distil off a part of the acid, till what 
 remains in the retort has the consistence of a syrup, 
 and this will form regular crystals, amounting to 58 
 parts from 100 of sugar. These crystals may be dis- 
 solved in water, re-crystallized and dried on blotting- 
 paper. 
 
 Honey, gum arabic, alcohol, the calculous concre- 
 tions in the kidneys and bladders of animals, silk, wool, 
 hair, and various other bodies, afford oxalic acid, by 
 distillation with nitric acid. Berthollet observes, that 
 the quantity of the acid afforded by vegetable matters 
 is in proportion to their nutritive qualities. 
 
 The crystals of oxalic acid effloresce in dry air, but 
 attract a little humidity if it be damp. They are solu- 
 ble in one part of hot, ancf two parts of cold water ; and 
 are decomposed by a red heat. When dissolved in 
 3600 times their weight of water, the solution still red- 
 dens litmus-paper, and is perfectly acid to the taste. 
 
 The oxalic acid is a good test for lime, for which it 
 has a greater affinity than any other acid. It forms with 
 lime, an insoluble salt, not decomposable except by tire, 
 and turning syrup of violets green. 
 
 Oxalic acid is capable of oxalizing lead, copper, iron, 
 tin, bismuth, nickel, cobalt, zinc, and manganese. 
 
 The combination of oxalic acid with the alkalies and 
 other bases, form the salts called oxalates.
 
 OXYMURIATIC ACID. 
 
 Oxalic acid dissolved in water is employed by calico 
 printers to destioy or lighten colours which are produced 
 by iron. It is also used to remove iron moulds, and to 
 take out spots of ink from furniture, and various other 
 articles, which it does with the greatest facility. The 
 crystals of oxalic acid much resemble those of Epsom 
 salt which are much used as a purgative : several unfor- 
 tunate accidents have happened through its having been 
 taken by mistake, as the corrosive power of this acid ia 
 very great, when taken in so large a dose as Epsom salt. 
 
 OXYMURIATIC ACID. 
 
 IF 84 parts of muriatic acid be combined with 16 of 
 oxygen, they form oxymuriatic acid. This combination 
 is usually formed by adding to one part of the black ox- 
 ide of manganese, two parts of strong muriatic acid, and 
 distilling the mixture with a gentle heat. The gas ob- 
 tained is received over water, by means of pneumatic 
 apparatus. 
 
 Oxymuriatic acid gas is tinged of a yellow colour by 
 contact with atmospheric air; it supports flame, but 
 cannot be breathed without the most injurious effects. 
 Pelletier having attempted to respire it, the consequence 
 was a consumption, which in a short time put a period 
 to his life. If it happen to be accidentally inhaled, the 
 vapour of volatile alkali, for which it has a strong affinity, 
 is the best remedy. It does not readily unite with water; 
 and at the temperature of freezing water it crystallizes. 
 
 Other acids become more intensely sour by an ad- 
 ditional dose of oxygen, but the muriatic has this pro- 
 perty diminished ly the same addition. The taste of 
 oxymuriatic acid is harsh and styptic, and instead cf 
 reddening vegetable colours, it changes them all to white, 
 and their colours cannot be restored either by acids or 
 alkalies. On this account, it has been extensively used 
 in the process of bleaching. After having thus been 
 employed upon a sufficient quantity of materials, it is 
 1C*
 
 186 CHEMISTRY. 
 
 converted into common muriatic acid. It has, therefore, 
 produced its effect by imparting oxygen. 
 
 As the oxymuriatic acid eradicates writing-ink, but 
 nas no effect upon printing-ink, it may be conveniently 
 used for whitening soiled books and prints; it removes 
 all stains but those of an oily nature. An easy mode of 
 preparing a quantity of it, consists in adding one ounce 
 of the red oxide of lead to three ounces of muriatic. 
 The red lead supplies the oxygen which oxygenizes th 
 acid. This preparation should not be made till near th 
 time against which it is wanted, and when made it 
 should be kept in the dark, as it is deoxygenized bv the 
 light. 
 
 The nitromuriatic and oxymuriatic acids have the 
 same appearance and odour, as well as the sajne effects, 
 as solvents. It appears, therefore, that the nitric acid, 
 when added to the muriatic, has only the effect of sup- 
 plying it with oxygen. 
 
 Oxymuriatic acid oxidizes nearly all the metals with 
 out the assistance of heat. It decomposes the red sul- 
 phuret of mercury, which neither the sulphuric nor the 
 nitric acid will accomplish. It may be combined with a 
 great number of bases; the salts which it forms detonate 
 with carbon and several metallic substances. 
 
 Hyper-oxymuriate of potass is made by introducing 
 the oxymuriatic acid gas into a solution of potass; its crys- 
 tals, as well as those of common muriate, being formed 
 by evaporation in the dark. It gives a faint taste, with 
 a sensation of coldness in the mouth ; the crystals have 
 somewhat of a silvery appearance, and emit light by 
 attrition. It is decomposed by the action of light, part- 
 ing with oxygen, and becoming simple muriate of potass. 
 Heat also separates its oxygen in the form of gas; 100 
 grains of it will yield 75 cubic inches of oxygen gas. 
 
 VV'hen three parts of hyper-oxy muriate of potass, and 
 one of sulphur, are triturated in a mortar, the mixture 
 detonates violently. The same effect is produced when 
 the mixture is struck with a hammer upon an anvil. 
 
 Phosphorus and hyper-oxy muriate of potass detonate 
 with prod : gious force.
 
 PHOSPHORIC ACID. 187 
 
 Exotic seeds which could not be caused to germinate 
 Dy ordinary means, have germinated after being steeped 
 or a few days in weak oxymuriatic acid. 
 
 PHOSPHORIC ACID. 
 
 THE purest phosphoric acid is obtained by the com 
 bustion of phosphorus in oxygen gas. If no moisture be 
 present, it is obtained in the form of white flocks, which 
 are very light, and have a strongly acid taste. These 
 flocks will attract moisture from the atmosphere, and 
 become a fluid acid. This acid may be concentrated 
 till its specific gravity exceeds that of the sulphuric 
 acid ; though strongly acrid, it is not corrosive, and has 
 no smell. 
 
 Phosphoric acid may likewise be obtained by heating 
 phosphorus with nitric or sulphuric acid ; it remains in 
 the retort, after these acids are driven over. Another 
 mode of forming it, consists in exposing phosphorus for 
 some weeks to the common temperature of the atmo- 
 sphere, by which means it is gradually converted into a 
 liquid acid. It is usually placed on the inclined side of a 
 funnel, through which the liquid which is formed drops 
 into a bottle placed beneath to receive it, and contain- 
 ing a little distilled water. The acid thus prepared, is 
 called phosphoric acid by deliquescence. 
 
 The quantity of acid obtained from phosphorus, is 
 generally about three times the weight of the phos- 
 phorus used. 
 
 If phosphoric acid be exposed to heat, it gradually 
 becomes thick and glutinous ; and if the heat be con- 
 tinued, it melts into a kind of glass, which is called the 
 glacial acid of phosphorus, or glacial phosphoric acid. 
 This glacial acid becomes liquid by exposure to the 
 atmosphere. 
 
 Phosphoric acid, when perfectly dry, sublimes in close 
 vessels, but the addition of water deprives it of this pro- 
 perty. If mixed with charcoal, or other inflammable 
 matter, and exposed to a strong heat, it parts with its 
 oxygen, and is converted into phos[V . ..s.
 
 188 CHEMISTRY. 
 
 Phosphoric acid, assisted 'by heat, has some action 
 upon silex, and will, therefore, decompose glass. 
 
 The salts of phosphorus are called phosphates. The 
 phosphate of lirne exists in bones, from which phospho- 
 rus is generally prepared. Whole mountains of phos- 
 phate of lime are said to exist in the province of Estre- 
 madura, in Spain. 
 
 PHOSPHOROUS ACID. 
 
 THE spontaneous combustion of phosphorus at the 
 temperature of the atmosphere, forms, in the first in- 
 stance, phosphorous acid, which contains less oxygen 
 than the phosphoric ; but, as phosphorous acid acquires 
 an additional quantity of oxygen from the atmosphere, 
 it is speedily converted into the phosphoric. 
 
 Phosphorous acid is, therefore, very little known. It 
 may, therefore, be decomposed by charcoal ; but cannot 
 be reduced to the glacial state. Its salts are called 
 phosphates. 
 
 PRUSSIC ACID. 
 
 THIS acid exists, combined with iron, in the fine blue 
 pigment, well known by the name of Prussian blue. It 
 may be obtained as follows: mix four ounces of Prussian 
 blue with two of red oxide of mercury, prepared by ni- 
 tric acid, and boil them in twelve ounces, by weight, of 
 water, till the whole becomes colourless; filter the liquor, 
 and add to it one ounce of clean iron filings, and six or 
 seven drachms of sulphuric acid : drain oft", by distillation, 
 about a fourth of the liquor, which will be prussic acid ; 
 though, as it is liable to be contaminated with a portion 
 of sulphuric acid, to render it pure, it may be rectified 
 by re-distilling it off carbonate of lime. 
 
 The prussic acid has a smell like that of peach blos- 
 soms. Its taste is at first sweetish, then acid and hot, 
 and it excites coughing. It is very volatile, and capable 
 >f existing in an acid in the gaseous form. 
 
 The prussic acid combines with earths, alkalies, and
 
 PRUSSIC ACID. 1 89 
 
 metallic oxides, forming the salts called prussiates. The 
 prussiate of potash and iron, often called the prussian 
 alkaii, is one of the most important of these compounds, 
 both for its utility as a test, and for making prussian blue. 
 To form it, two parts of bullock's blood, and one of 
 potash, are calcined by a moderate heat in a covered 
 crucible, containing a hole in the lid. The calcination 
 is to be discontinued when the matter ceases to afford a 
 small blue flame. The residuum must be lixiviated with 
 a small quantity of cold water. In this state, the prus- 
 siate of potass may be employed for making prussian 
 blue, though not pure enough for the use of the chemist. 
 Henry recommends it to be obtained by the following 
 process from prussian blue, when required quite pure : 
 To a solution of potass, deprived of its carbonic acid by 
 quick-lime, and heated nearly to the boiling point, add 
 by degrees powdered prussian blue, till its colour ceases 
 to be discharged. Filter the liquor, wash the sediment 
 with water, till it ceases to extraot any thing, mix the 
 washings together, and pour the mixture into an earthen 
 dish in a sand-heat. When the solution has become hot, 
 add a little diluted sulphuric acid, and continue the heat 
 about an hour. A copious precipitate of pru&sian blue 
 will be formed, which must be separated by alteration. 
 Assay a small quantity of the filtered liquor in a wine- 
 glass, with a little diluted sulphuric acid. If an abundant 
 production of prussian blue still take place, the whole 
 liquor must be exposed again to heat with a little diluted 
 sulphuric acid, and this must be repeated as often as is 
 necessary- Into the liquor thus far purified, pour a solu- 
 tion of sulphate of copper in four or six times its weight 
 of warm water, as long as a reddish brown precipitate 
 continues to appear. Wash the precipitate, which is a 
 prussiate of copper, with repeated effusions of warm 
 water ; and when the water comes oflf colourless, lay the 
 precipitate on a linen filter to drain, after which it maj 
 be dried on a chalk-stone. When the precipitate is dry, 
 powder it, and add it by degrees to a solution of potass, 
 which will take the prussic acid from the oxide of copper
 
 190 CHEMISTRY. 
 
 This prussiate of potass, however, will be contaminated 
 by some portion of sulphate of potass, from part of 
 which it may be freed by gentle evaporation, as the sul- 
 phate crystallizes first. To the remaining liquor, add a 
 solution of barytes in warm water, as long as a white 
 precipitate ensues, observing not to add more after its 
 cessation. The solution of prussiate of potass will now 
 be freed in a great measure from iron, and entirely from 
 sulphate, and by gentle evaporation, will form, on cooling, 
 beautiful crystals. These, dissolved in cold water, afford 
 the purest prussian alkali that can be prepared. If 
 pure barytes be not at hand, acetate of barytes may be 
 used instead ; as the acetate of potass formed, not being 
 crystallizable, will remain in the mother-water. 
 
 Prussiates of soda and of ammonia may be prepared 
 in a similar way to the prussiate of potass, above de- 
 scribed. 
 
 PYROLIGNEOUS ACID. 
 
 Lv the destructive distillation of wood, an acid Is 
 obtained, which was formerly called acid spirit of wood, 
 and since pyroligneous acid. Fourcroy and Vanquelin 
 showed that this acid was merely the acetic contamina- 
 ted with empyreumatic oil and bitumen. 
 
 Monge discovered, that this acid has the property of 
 preventing the decomposition of animal substances. Mr. 
 Wm. Dinsdale, of Field Cottage, Colchester, three years 
 prior to the date of Monge's discovery, did propose to 
 the Lord Commissioners of the Admiralty, to apply a 
 pyroligneous acid, prepared out of the contact of iron 
 vessels, which blacken it, to the purpose of preserving 
 animal food, wherever their ships might go. As this 
 application may in many places afford valuable anti- 
 corbutic articles of food, and thence might be eminently 
 conducive to the health of seamen ; it is to be hoped 
 that Mr. Dinsdale's ingenious plan might be carried into 
 effect, as far as is deemed necessary. It is sufficient to 
 plunge meat for a few moments into this acid, even 
 slightly empyreumatic, to preserve it as long as you
 
 PYROLIGNEOUS ACID. 191* 
 
 please. Putrefaction, it is said, not only stops hut retro 
 grades. To the empyreumatic oil a part of this effect 
 has been ascribed ; and hence has been accounted for, 
 the 'agency of smoke in the preservation of tongues, 
 hams, herrings, &c. Dr. Jorg, of Leipsic, has entirely 
 recovered several anatomical preparations from incipient 
 corruption by pouring this acid over them. With the 
 empyreumatic oil or tar he has smeared pieces of flesh 
 Iready advanced in decay, and notwithstanding that the 
 weather was hot, they soon became dry and sound. Mr. 
 Ramsey has added the following facts in the 5th number 
 of the Edinburgh Philosophical Journal. If fish be sim- 
 ply dipped in redistilled pyroligneous acid, of the specific 
 gravity 1.012, and afterwards dried in the shade, they 
 preserve perfectly well. On boiling herrings treated in 
 this manner, they were very agreeable to the taste, and 
 had nothing of the disagreeable empyreuma which those 
 of his earlier experiments had, which were steeped for 
 three hours in the acid. A number of very fine had- 
 docks were cleaned, split, and slightly sprinkled with salt 
 for six hours. After being drained, they were dipped for 
 about three seconds in pyroligneous acid, then hung up 
 in the shade for about six days. On being broiled, the 
 fish were of an uncommon fine flavour, and delicately 
 white. Beef treated in the same way, had the same 
 flavour as the Hamburgh beef, and kept as well. Mr. 
 Ramsey has since found, that his perfectly purified vine- 
 gar, specific gravity 1.034, being applied by a cloth or 
 spunge to the surface of fresh meat, makes it keep swee 
 and sound for many days longer in summer, than it other- 
 wise would. Immersion for a minute in his purified 
 common vinegar, specific gravity 1.009, protects beef sttid 
 fish from all taints in summer, provided they be hung up 
 and dried in the shade. When by frequent use the 
 pyroligneous acid has become impure, it may be clarified 
 by beating up 20 gallons of it. with a dozen of eggs in 
 the usual manner, and heating the mixture in an iron 
 boiler. Before boiling, the eggs coagulate, and bring the 
 impurities to the surface of the boiler, and are of
 
 1 92 CHEMISTRY. 
 
 course to be carefully skimmed off The acid must be 
 immediately withdrawn from the boiler, as it acts on 
 iron. .,, * \ 
 
 This acid has long been prepared for the calico-print- 
 ers. The following arrangement of apparatus has been 
 found to answer very well. A series of cast-iron cylin- 
 ders, about four feet diameter, and six feet long, are set 
 in pairs, horizontally, in brick-work, so that the flame 
 of one fire may play round both. Both ends project a 
 little from the brick-work : one of them has a cast-iron 
 plate well fitted, and firmly bolted to it, from the centre 
 of which, an iron pipe, about six inches in diameter, 
 proceeds, and enters, at a right angle, the main cool- 
 ing-pipe. The diameter of this main pipe 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 an iron plate, smeared round 
 its edge with clay, and secured in its place by wedges. 
 The charge of wood for such cylinders is about 8 cwt. 
 
 The hard woods, oak, ash, birch, and beech, are alone 
 used ; but 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 
 charcoal is removed, and a new charge of wood is intro- 
 duced. The average product of wood vinegar, or raw 
 pyroligneous acid, is thirty-five gallons. It is much con- 
 taminated with tar, is of a deep brown colour, and has a 
 specific gravity of 1.025 ; so that its weight is about 3 
 cwt. ; but the residuary charcoal is found to weigh no 
 more than one-fifth of the wood employed. 
 
 The raw pyroligneous is rectified by a second distilla- 
 tidh in a copper-still, in the body of which, about 20 gal- 
 lons of viscid tarry matter is left from every 100 of 
 vinegar, and then passes over a transparent, but brown 
 vinegar, having a considerable smell, and its specific 
 gravity is 1.013. Its acid powers are superior to those 
 of the best wine or malt vinegar, in the proportion of 
 three to two.
 
 RUCUMIC, ROSACIC, AND SEBAC1C ACID. 193 
 
 RUCUMIC ACID. 
 
 A* acid said to be peculiar to rhubarb, but not yet 
 sufficiently examined. 
 
 ROSACIC ACID. 
 
 THERE is deposited from the urine of persons labour- 
 ing under gout and inflammatory fevers, a sediment of a 
 rose colour, occasionally in reddish crystals. It was at 
 first discovered to be a peculiar acid by M. Proust, and 
 afterwards examined by M. Vanquelin. This acid is 
 solid, of a lively cinnabar hue, without smell, with a 
 faint taste, but reddening litmus very sensibly. On 
 burning coal it is decomposed into a pungent vapour, 
 which has not the odour of burning animal matter. It is 
 very soluble in water, and even softens in the air. It is 
 soluble in alcohol. It forms soluble salts with potassa, 
 soda, ammonia, barytes, strontites, and lime. It gives a 
 slight rose-coloured precipitate, with acetate of lead. It 
 also combines with lithic acid, forming so intimate a 
 union, that the lithic acid in precipitating from urine, 
 carries the other, through a deliquescent substance, down 
 along with it. It is obtained pure by acting on the sedi- 
 ment of urine with alcohol. 
 
 SEBACIC ACID. 
 
 SUBJECT to a considerable heat 7 or 8 pounds of hJg's 
 lard, in a stone-ware retort capable of holding double 
 the quantity, and connect its beak by an adopter with a 
 cooled receiver. The condensible products are chiefly 
 fat, altered by the fire, mixed with a little acetic and 
 sebacic acids. Treat this product with boiling water 
 several times, agitating the liquor, allowing it to cool, and 
 decanting each time. Pour at last into the watery liquid, 
 solution of acetate of lead in excess. A white flocculgnt 
 precipitate of sebate of lead will instantly fall, which 
 must be collected on a filter, washed and dried. Put the 
 17 N
 
 104 CHEMISTRY. 
 
 sebate of lead into a phial, and pour upon it its own 
 weight of sulphuric acid, diluted with five or six time* 
 its own weight of 'water. Expose this phial to the het 
 of about 212. The sulphuric acid combines with the 
 oxide of lead, and sets the sebacid acid at liberty. Filter 
 the whole while hot. As the liquid cools, tfye sebacid 
 acid crystallizes, which must be washed, to free it from 
 the adhering sulphuric adTd. Let it then be dried at a 
 gentle heat. . 
 
 The sebacid acid is inodorous ; its taste is slight, but 
 it perceptibly reddens litmus paper ; its specific gravity 
 is above that of water, and its crystals are small white 
 needles of little coherence. Exposed to heat, it melts 
 like fat, is decomposed, and partially evaporated. The 
 air has no effect upon it. It is much more soluble in hot 
 than in cold water ; hence boiling water saturated with 
 it, assumes a nearly solid consistence on cooling. Alco- 
 hol dissolves it abundantly at the common temperature. 
 
 With the alkalies it forms soluble neutral salts: but 
 if we pour into them concentrated solutions, sulphuric, 
 nitric, or muriatic acids, the sebacic is immediately 
 deposited in large quantity. It affords precipitates with 
 the acetates and nitrates of lead, mercury, and silver. 
 
 Such is the account given by Thenard of this acid. 
 
 SELINIC ACID. 
 
 IF selinium be heated to dryness, it forms, with nitric 
 acid, a volatile and crystallizable compound, called se- 
 linic acid, which unites to some of the metallic oxides, 
 producing salts called seleniates. 
 
 SORBIC ACID 
 
 FROM sorbus, the mountain-ash, from the berries of 
 which it is obtained. The acid of apples, called malic, 
 may be obtained most conveniently, and in the greatest 
 purity, from the berries of the mountain-ash, called sor- 
 bus, or pyrus aucuparia ; and hence, the present name
 
 SORBIC ACID. 195 
 
 sorbic acid. This was supposed to be a new and pecu- 
 liar acid by Donovan and Vanquelin, who wrote good 
 dissertations upon it. But it now appears, that the sorbic 
 and pure malic acids are identical. 
 
 Bruise the ripe berries in a mortar, and then squeeze 
 them in a linen bag. They yield nearly half their 
 weight of juice, of the specific gravity of 1.077. This 
 viscid juice, by remaining for about a fortnighf in a 
 warm temperature, experiences the vinous fermenta- 
 tion, and would yield a portion of alcohol. By this 
 change, it has become bright, clear, and passes easily 
 through the filter, 'while the sorbic acid itself is not al- 
 tered. Mix the clean juice with a filtered solution of 
 acetate of lead, separate the precipitate on a filter, and 
 wash it with cold water. A large quantity of boiling 
 water is then to be poured upon the filter, and allowed 
 to drain in glass jars. At the end of some hours, the 
 solution deposits crystals of great lustre and beauty 
 Wash these with cold water, dissolve them in boiling 
 water, filter, and crystallize. Collect the new crystals, 
 and boil them for half an hour in two or three times 
 their weight of sulphuric acid, specific gravity of 1.090 
 supplying water as fast as it evaporates, and stirring 
 the mixture diligently with a glass rod. The clear 
 liquor is to be decanted into a tall, narrow glass jar, 
 and, while still hot, a stream of sulphuretted hydrogen 
 is to be passed through it. When the lead has been all 
 thrown down in a sulphuret, the liquor is to be filtered, 
 and then boiled in an open vessel, to dissipate the ad- 
 hering sulphuretted hydrogen. It is now a solution of 
 sorbic acid. When it is evaporated to the consistence 
 of a syrup, it forms mamelated masses, of a crystalline 
 structure. It still contains considerable water, and de- 
 liquesces when exposed to the air. Its solution is trans- 
 parent, colourless, void of smell, but powerfully acid to 
 the taste. Lime and barytes waters are not precipitated 
 by solution of the sorbic acid, although the sorbate of 
 lime is nearly insoluble. One of the most characteristic 
 properties of this acid is the precipitate which it gives
 
 106 CHEMISTRY. 
 
 with the acetate of lead, which is at first white and 
 flocculent, but afterwards assumes a brilliant, crystal- 
 line appearance. With potassa, soda, and ammonia, 
 it forms crystallizable salts, containing an excess of acid. 
 
 STANNIC ACID. 
 
 A ITAME which has been given to the peroxide of tin, 
 because it is soluble in alkalies. 
 
 SUCCINIC ACID, 
 
 THIS acid is obtained from amber, which is a brown 
 transparent, combustible substance, dug out of the 
 earth, in some countries, and found upon the sea-coast 
 in others. 
 
 During the distillation of amber, the crystals of this 
 acid attach themselves to the neck of the retort. They 
 were formerly called salt of amber. When purified 
 by repeated solution in hot water, filteration, and re- 
 crystallization, they are white, shining, triangular prisms. 
 Their taste is slightly acid : they redden tincture of lit- 
 mus, but have no effect on syrup of violets. 
 
 This acid obtains its name from succinum, the Latin 
 name of amber. Its salts are called succinates. 
 
 SUBERIC ACID. 
 
 THIS acid exists in cork. It is obtained by distilling 
 nitric acid of cork grated to powder, till the cork ac- 
 quires the consistence of a wax, and no more red fumes 
 appear. The residuum is placed in a sand-heat, and 
 continually stirred, till white penetrating vapours appear. 
 It is then removed from the sand-heat, and stirred till 
 told. Boiling water is poured upon the product ; heat 
 is applied till it liquifies and it is then filtered. A sedi- 
 ment is deposited, which must be separated by the filter 
 and the fluid evaporated nearly to dry ness. The mass 
 thus obtained is the suberic acid. It may be further
 
 SULPHURIC ACID. 197 
 
 purified by saturating it with potass, and precipitating il 
 by means of an acid ; or by boiling it alofig with char 
 coal powder. 
 
 Suberic acid is not rrystallizable; boiling water dis- 
 solves half its weight of it, but it is nearly insoluble in 
 cold water. Its taste is acid, and slightly bitter. Jt 
 reddens most vegetable blues, but has the peculiar prop- 
 erty of changing the solution of indigo in sulphuric acid 
 to a green. 
 
 It attracts moisture from the atmosphere, and exposure 
 to light renders it brown. It has no action on gold 01 
 nickel, but oxidixes most of the other metals. With 
 diiferent bases, its salts are called suberates. 
 
 SULPHURIC ACID. 
 
 SULPHURIC acid is the union of oxygen and sulphur, in 
 which the proportion of sulphur is, according to Berthollet, 
 63.2, and that of oxygen 36.8. 
 
 Sulphuric acid is strongly corrosive and destitute of 
 colour and smell. It may be rendered twice the weight 
 of water, but its customary specific gravity seldom ex- 
 ceeds 1.8. When concentrated only to 1.7, it will freeze 
 sooner than water, but not if either more or less concen- 
 trated. This was discovered by Keir. Sulphuric acid 
 is so intensely acidulous, that though diluted with 7000 
 times its weight of water, its taste is siill distinguishable. 
 
 Sulphuric acid was formerly procured by distillation 
 from the salt which, previous to the adoption of the new 
 nomenclature, was called green vitriol ; on this account, 
 and its having in some measure an oily consistence, it 
 was called oil of vitriol. At present, it is furnished for 
 the demand of trade, by burning sulphur in close cham- 
 bers, with the addition of nitrate of potass to supply 
 oxygen. The floor of the chamber is covered by a 
 leaden cistern, containing water, by which the vapouis 
 of the sulphur are attracted and condensed. This pro- 
 cess does not furnish the acid in a state of purity ; but 
 at least communicates to it some of the foreign substances 
 'ead and potass. It is purified by distillation. 
 17*
 
 198 CHEMISTRY. 
 
 Sulphuric acid speedily destroys the texture of animal 
 and vegetable substances; it changes all vegetable blues 
 to red, with the exception of indigo. It has a strong 
 attraction for water, of which Neuman asserts it will 
 abstract from the atmosphere G.25 of its own weight. 
 
 When sulphuric acid is mixed with water, much ca 
 loric is evolved, and the specific gravity of the compound 
 is greater than intermediate. The mixture of four 
 pounds of acid, with one of water, will raise the ther 
 mometer to 300. 
 
 Sulphuric acid decomposes alcohol and the oils; when 
 assisted by heat, it decomposes most of the metallic 
 oxides, and most readily those which contain the greatest 
 quantity of oxygen, as the red oxide of lead, the clack 
 oxide of manganese. 
 
 It oxidizes iron, zinc, and manganese in the cold. 
 Assisted by heat, it oxidizes silver, mercury, copper, 
 antimony, bismuth, arsenic, tin, and tellurium. At a 
 boiling heat, it oxidizes lead, cobalt, nickel, and molybde- 
 num. It has no action upon gold, platina, tungsten, or 
 titanium. 
 
 It unites readily with all the alkalies, and alkaline 
 earths, also with alumine, and zircon ; with which, and 
 most of the metallic oxides, it forms salts, which are 
 called sulphates; thus sulphate of potass, formerly called 
 vitriolated tartar, is a combination of the sulphuric acid 
 and potass, and sulphate of soda (Glauber's salts,) is a 
 combination of sulphuric acid and soda. 
 
 SULPHUROUS ACID. 
 
 - IF sulphuric acid be deprived of part of its oxygen, it 
 is converted into sulphurous acid ; but the 'quantity of 
 oxygen which must be abstracted to effect this change 
 or, in other .words, the quantity of oxygen which is con 
 tained in sulphurous acid, has never been ascertained. 
 
 Sulphurous acid is the result of a very slow combus- 
 tion of sulphur ; whereas, in a rapid combustion, the 
 sulphur combines with more oxygen, and forms sulphurs 
 acid
 
 TARTARIC ACID. 19 J 
 
 It is usually procured by mixing, with sulphuric acid. 
 Dil, grease, metals, or any other substance that has a 
 stronger affinity for oxygen than sulphuric acid, and pro- 
 ceeding to distillation. Sugar is one of the best substances 
 which can be employed. By this means, the acid may 
 be obtained in a gaseous form, in which state it is colour- 
 less and invisible, like common air, exhales the odour of 
 burning sulphur, and cannot be breathed without suffb* 
 cation. Extreme cold converts it into a liquid. When 
 combined with water, for which it has a strong attrac- 
 tion, it does not entirely lose its smell like sulphuric 
 acid. 
 
 Blue vegetable colours are reddened by sulphurous 
 acid, previous to their being discharged. 
 
 This acid does not oxidize so many of the metals as 
 sulphuric acid. The metals upon which it has this effect, 
 appear to be only iron, zinc, and manganese. 
 
 With the alkalies, alkaline earths, alumine, and some 
 of the metallic oxides, it forms the salts called sulphites. 
 
 TARTARIC ACID. 
 
 A HARD substance is found adhering to the sides of 
 casks in which some kinds of wine have been fermented : 
 this substance is tinged with the colour of the wine ; but, 
 when it has been purih'ed by solution, filteration, and 
 crystallization, it constitutes the salt called cream of 
 tartar. Cream of tartar consists of potass, united to a 
 peculiar acid : this acid is tartaric acid. Cream of tar- 
 tar is supertartrate of potass. 
 
 To obtain tartaric acid, four parts of supertartrate of 
 potass may be boiled in twenty parts of water, and one 
 part of sulphuric acid added gradually. By continuing 
 the boiling, the sulphate of potass will fall down. When 
 the liquor is reduced to one-half, it is to be filtered, and 
 if any more sulphate be deposited by continuing the boil- 
 ing, the filtering must be repeated. When no more is 
 thrown down, the liquor is to be evaporated to a syrup ; 
 and thus :rystals of tariaric acid equal to half the weigh!
 
 200 
 
 CHEMISTRY. 
 
 Dl the tartar employed, will be obtained. These crys- 
 tals readily dissolve in water, and the solution crystallizes 
 by evaporation. 
 
 The tartaric acid does not oxidize platina, gold, silver 
 lead, bismuth or tin ; and its action on antimony and 
 nickel is very slight. It unites with the alkalies, and most 
 of the earths. The salts formed with it are called tar- 
 trates. 
 
 The supertartrate of potass, from which this acid is 
 obtained, is much used in medicine; it is cooling, and 
 gently aperient : in domestic economy, it is dissolved in 
 water, and, with the addition of a little sugar and a few 
 slices of lemon, forms, after standing a day or two, an 
 agreeable beverage, called imperial water. An infusion 
 of green balm, instead of water, improves this liquor. 
 
 Mixed with an equal weight of nitre, and thrown into 
 a red hot crucible, supertartrate of potass detonates, 
 and forms the white flux ; with half its weight of nitre, 
 it forms the black flux ; and by simple mixture with 
 nitre in various proportions, it is called raw flux. It is, 
 likewise, used in dyeing, gilding, whitening pins, and other 
 arts. 
 
 TELLIRIC ACID. 
 
 THE oxide of tellurium combines with many of the 
 metallic oxides, acting the part of an acid, and produ- 
 cing a class of compounds which have been called tellu- 
 rates. 
 
 TUNGSTIC ACID. 
 
 THIS acid has been found only in two minerals ; one 
 of which, formerly called tungsten, is a tungstate of 
 lime, and is very rare ; and the other, more common, is 
 composed of tungstic acid, oxide of iron, and a little 
 oxide of manganese. The acid is separated from the 
 latter in the following way : The wolfram, cleared from 
 its silicious gangue, and pulverized, is heated in a mat- 
 trass, with five or six times its weight of muriatic acid, 
 r 'jr half an hour. The oxides of iron and manganese
 
 TUNGSTOUS ACID, ZUMIC ACID, ZOONIC ACID. 201 
 
 being thus dissolved, we obtain tungstic acid in the forru 
 of a yellow powder. After washing it repeatedly with 
 water, it is then digested in an excess of liquid ammonia 
 heated, which dissolves it completely. The liquor is 
 filtered and evaporated to dryness in a capsule. The 
 dry residue being ignited, the ammonia flies off, and pure 
 tungstic acid remains. If the whole of the wolfram has 
 not been decomposed in this operation, it must be sub- 
 jected to the muriatic acid again. 
 
 It is tasteless, and does not affect vegetable colours. 
 The tungstates of the alkalies and magnesia are soluble 
 and crystallizable, the other earthy ones are insoluble, as 
 well as those of the metallic oxides. The acid is com- 
 posed of 100 parts pure metallic tungsten, and 25 or 26-4 
 oxygen. 
 
 TUNGSTOUS ACID. 
 
 WHAT has been thus called appears to be an oxide of 
 tungsten. 
 
 ZUMIC ACID. 
 
 Air acid produced from vegetable substances, which 
 have undergone acetous fermentation. Its claim to be 
 considered as a distinct compound is doubtful. (See 
 Nuncic Acid.) 
 
 ZOONIC ACID. 
 
 IN the liquid procured by distillation from animal sub- 
 stances, which had been supposed only to contain car- 
 bonate of ammonia and an oil, Berthollet imagined he 
 had discovered a peculiar acid, to which he gave the 
 name of zoonic. Thenard has demonstrated, however 
 that it is merely acetic acid combined with animal 
 matter.
 
 202 CHEMISTRY. 
 
 OF ALKALIES. 
 
 ALKALIES are possessed of the following properties: 
 
 1. They are soluble in water ; 2. they have an acrid 
 and urinous taste ; 3. they are incombustible ; 4. they 
 change most vegetable blues to green, and the yellow to 
 a brown ; 5. they form neutral salts with acids ; 6. they 
 render oils miscible with water. 
 
 Potass and soda are called fixed alkalies, because they 
 are not volatilized except by an intense heat; ammonia 
 is called the volatile alkali, because it is dissipated or 
 converted into gas at a moderate heat. 
 
 Oxygen is a compound part of all the alkalies, and 
 appears clearly in the case of two fixed alkalies, to be 
 the alkalizing principle. The bases of the alkalies are 
 rnetals. 
 
 Tible of saline products of one thousand pounds of 
 ashes of the following vegetables : 
 
 SALINE PRODUCTS. 
 
 Stalks of Turkey wheat or maize, 198 Ibs. 
 
 Stalks of sun-flower, .... 349 " 
 
 Vine branches, 162.6 
 
 Elm, 166 
 
 Box, 78 
 
 Sallow, 102 
 
 Oak, Ill 
 
 Aspen, -------- 61 
 
 Beech, 219 
 
 Fir, 132 
 
 Fern cut in August, - - - - 117 
 
 Wormwood, - - - - '- - 748 
 
 Fumitory, ....... 360 
 
 Heath, 115
 
 POTASS. 203 
 
 POTASS. 
 
 IF the ashes of burnt vegetables be repeatedly lixi- 
 viated, until they cease to communicate any taste to the 
 water, and the water be evaporated to dryness, a 
 saline residue is obtained, which in commerce is known 
 by the name of potash. It has been called the vegetable 
 alkali, because it was supposed to be furnished by vege- 
 tables only. 
 
 Potash contains a number of foreign salts, and other 
 impurities; but when deprived of all these, it is called 
 by chemists potass. 
 
 Pure potass is extremely white, and so caustic, that if 
 applied to the hand, the skin is instantly destroyed ; it is 
 therefore in this state called caustic alkali. 
 
 The potash of commerce is always combined with 
 carbonic acid, for which it has a strong affinity, and it is 
 this addition which disguises its properties more than all 
 the resr. and reduces it to its usual state of what is 
 called mild alkali, or by chemists carbonate of potass, 
 or rather tub-carbonate of potass, as it is not saturated 
 with the Carbonic acid. 
 
 If potash be dissolved in water, and mixed with an 
 equal quantity of quick-lime made into a paste with the 
 same fluid, the lime having a greater affinity for the 
 carbonic acid than the potass, will combine with it; the 
 potash remains in solution, and may be separated from 
 the lime by alteration. The evaporation of this solution 
 should be performed in close vessels, otherwise the potass 
 will abstract carbonic acid from the air. 
 
 Potass is soluble in its weight of water. It attracts 
 moisture from the gases with avidity ; and, therefore, 
 affords the means of drying them. It is soluble, also, in 
 alcohol, which is not the case when it is in a state of 
 carbonate. 
 
 By exposure to heat, potass becomes soft ; and at the 
 commencement of ignition, it melts into a transparent 
 glass ; by increasing the heat, it is volatilized. 
 
 Potass and silex, when fused together in equal quau-
 
 204 CHEMISTRY. 
 
 ties, combine, and form glass. If the proportion of po- 
 tass to. (hat of silex be as three or four to one, the glass 
 will be soft and soluble in water. This composition is 
 called siliceous potass, or liquor of flints. 
 
 If a solution of potass be boiled upon silex recently 
 procured, it dissolves a part of it. As the solution cools, 
 it assumes the appearance of a jelly, even though pre- 
 viously diluted with seventeen times its weight of water. 
 
 Potass, combined with fixed oils, forms soap. 
 
 It combines with sulphur, both in the dry and the 
 humid way, forming sulphuret of potass. When this 
 sulphuret is obtained by the fusion of its component parts, 
 it is of a brown colour, soluble in water, and soon attracts 
 water from the atmosphere. When it has acquired 
 moisture, it is then in a state to act on the air, from 
 which it will abstract oxygen ; and, if inclosed with a 
 quantity of it in a jar, the nitrogen will be left alone. 
 
 Sulphuret of potass, allowed to remain moist in the 
 atmosphere, is at length converted into sulphate of po- 
 tass; for the sulphur, combining with oxygen, forms sul- 
 phuric acid, and the water is decomposed, giving out 
 sulphuretted hydrogen gas. 
 
 SODA. 
 
 SODA, called also mineral, or fossil alkali, because it 
 was considered as exclusively derived from the mineral 
 kingdom, is nearly similar to potass in its properties. 
 
 5$oda is one of the most abundant substances, but ii 
 nver met with naturally, except in a state of combina- 
 tion. It forms common salt when combined with mu- 
 riatic acid, and this acid is, therefore, called muriate of 
 soda. Hence, those inexhaustible mines of salt which 
 are found in England, Poland, and other countries, and 
 even the ocean itself, which holds it in solution, are so 
 many vast depositaries of soda. 
 
 The French chemists have attempted to obtain muri 
 atic acid and soda, by the decomposition of sea-salt, but 
 the process is too expensive for general use. The soda
 
 SODA. 205 
 
 t>( commerce is therefore obtained from the ashes of 
 marine plants, and from one of these (the salsola soda] 
 it derives its name. In Scotland, this and other sea- 
 weeds are collected, dried, and burned in pits dug in the 
 sand, or in heaps surrounded by loose stones. Frtsh 
 quantities are added, as the first are consumed, anu a 
 hard residuum is obtained, which is of a black or bluish 
 colour ; it is called kelp, and contains from 2^ to 3 per 
 cent of soda. On the coasts of France and Spain the 
 same kind of manufacture is carried on*, and the produce 
 is called barilla. The barilla of Alicant is much noted. 
 
 Soda is obtained from kelp and barilla by lixiviation, 
 filteration, and crystallization. These processes leave it 
 in the state of a carbonate, but it may be deprived of 
 its carbonic acid, and rendered caustic, by lime, in the 
 same manner as potass. 
 
 Potass and soda, in a state of purity cannot be distin- 
 guished by inspection from each other The oxalic acid 
 has been used as a test to distinguish them. This acid, 
 with potass, forms a very soluble salt, but with soda one 
 of difficult solubility. A solution of the ore of platina 
 in nitro-muriatic acid, also affords the means of dis- 
 tinguishing them ; for the solution of potass will form a 
 yellow precipitate, bul soda gives no precipitate. 
 
 Fourcroy suggests that soda is the most proper of the 
 two fixed alkalies to be employed in medicine ; because 
 animal substances always contain it, but they never con- 
 tain potass. 
 
 If potass be exposed to the atmosphere, it deliquesces, 
 that is, acquires moisture ; if soda be exposed in the 
 same manner, it effloresces, that is, parts with moisture, 
 and is converted into a dry powder. 
 
 Soda is preferred to potass in most manufactures, its 
 affinities in general are not so strong as those of potass, 
 it is therefore less corrosive. It is more fusible alone, 
 and fuses silex more readily than potass, hence it is em- 
 ployed in manufacture of glass. 
 
 Carbonic acid renders soda, as well as potass, fit for 
 many purpose* to which, in its caustic state, it would 
 18
 
 206 CHEMISTRY. 
 
 not be applicable. It is in this state that these -ilkalies 
 are employed, in medicine, and in washing linen. 
 
 The combination of potass or soda with oil or tallow, 
 forms soap; but soda forms hard soap, while potass only 
 affords soft soap. Soda is therefore much more valuable, 
 and generally used in the manufacture of soap, for which 
 use it is rendered caustic, by quick-lime. Muriate of 
 soda is added in making soap, in order to harden it. The 
 brown or yellow soap contains a quantity of rosin. Black 
 or green soft soap is made with the coarsest oils, and 
 retains all its alkaline ley. 
 
 The weakest acids have the power of decomposing 
 soap, because they have a stronger affinity for its alkali 
 than the oil. Soap is also decomposed by metallic oxides, 
 earths, and neutral salts. Hence the water of springs 
 is said to be hard, because soap is not soluble in it, or 
 rather is not decomposed by it Solution of soap may 
 therefore be employed to show whether water holds min 
 era Is in solution or not. 
 
 AMMONIA. 
 
 IF muriate of ammonia, in powder, be mixed with 
 ,hree parts of slacked lime, and distilled, and the pro- 
 duct be collected by the mercurial trough, or pneumatic 
 apparatus, a gas is obtained, which is transparent and 
 colourless, like common air. This gas is called ammoni- 
 acal gas, and is the purest state in which ammonia can 
 oe exhibited. 
 
 Ammonia has a pungent, though not unpleasant smell 
 Its taste is acrid and caustic, like that of the fixed alka- 
 lies, but not so strong ; nor has it the property, like them, 
 of corroding animal substances. It is not respirable. 
 Its specific gravity to common air is as 3 to 5. When 
 exposed to a cold of 45, it is condensed in a liquid, which 
 again assumes the gaseous form, when the temperature 
 is raised. 
 
 Ammonia is rapidly absorbed by water, and the absorp 
 lion goes on till the water has acquired more than n
 
 AMMONIA. 207 
 
 Jiird of its weight of it. It therefore instantly disappears 
 if water be introduced into a jar of it; some caloric ia 
 evolved, and the specific gravity of the water is dimin- 
 ished. If ice be introduced into this gas, it melts and 
 absorbs the ammonia, while at the same time its tempera- 
 ture is dimished. The specific gravity of water saturated 
 with ammonia, at 60 is 9054. It is the attraction of 
 water for ammonia, which renders it necessary to em- 
 ploy mercury in obtaining the gas. 
 
 Water combined with ammonia, acquires its smell, 
 and has a disagreeable taste; it converts vegetable blues 
 to green. It is this liquid solution of ammonia which is 
 meant in speaking of the volatile alkali. When heated 
 to the temperature of 130, the ammonia separates in 
 the form of gas. When its temperature is reduced to 
 46, it crystallizes; and when suddenly cooled down to 
 68, it assumes the appearance of a thick jelly, and has 
 scarcely any smell. 
 
 Ammonia may be obtained by the dry distillation of 
 bones and other animal matters ; it is from such substan- 
 ces that it is obtained to supply the demand of commerce, 
 and it is sold under the name of spirits of hartshorn. 
 The product of the first distillation from bones, &c. is 
 very impure: it is therefore improved by repeated dis- 
 tillations. 
 
 Berthollet's experiments evince that one thousand 
 parts of ammonia consist of 807 parts of nitrogen, and 
 J93 parts of hydrogen; Sir H. Davy having discovered 
 oxygen to be the alkalizing principle in potass and soda, 
 was convinced of the probability of its existing in am- 
 monia. His researches confirmed this opinion, and he 
 concludes the proportion of oxygen in ammonia to be at 
 least 7 or 8 per cent. He also succeeded in separating 
 from it a substance of a metallic nature. The ammonia 
 was decomposed by galvanism in contact with mercury. 
 The mercury, by combining with about one twelve-thou- 
 sandth part of this new matter, has its identity destroyed, 
 it becomes solid, and its specific gravity is reduced from 
 13.5 to less than 3.0, but its colour, lustre, opacity, and
 
 208 CHEMISTRY. 
 
 conducting powers remain. The difficulty of obtaining 
 and operating upon this substance, has hitherto prevented 
 its being sufficiently known to assign its proper place in 
 the classification of bodies. 
 
 Ammonial gas has no effect upon sulphur or phosphorus. 
 Charcoal absorbs it, without altering its properties when 
 cold ; but when the gas is made to pass through red-not 
 charcoal, part of the charcoal combines with it, an" 
 forms prussic acid. 
 
 The two gaseous substances, ammonia and muriatic 
 acid, combine rapidly, and form the solid substance called 
 muriate of ammonia, which is the sal-ammoniac of com- 
 merce. This is one of the most remarkable and curious 
 facts : separately, ammonia and muriatic acid gas are 
 two of the most pungent and volatile substances known ; 
 in union they are hard, inodorous, not volatile, and possess 
 but little taste. 
 
 Muriate of ammonia was formerly supplied by Egypt, 
 but it is now made in other courttries (England for in- 
 stance) from soot. 
 
 Ammonia combines with oils, and forms soap ; it does 
 not combine with the metals, but it changes some of 
 them into oxides, and then dissolves them. Liquid am- 
 monia is capable of dissolving the oxides of silver, copper, 
 iron, tin, nickel, zinc, bismuth, and cobalt Its use in 
 medicine is considerable. 
 
 PEARL-ASH. 
 
 Aw impure potassa obtained by lixiviation from the 
 ashes of plants. 
 
 POTASH. 
 See Potass
 
 SALTS. 209 
 
 OF SALTS. 
 
 THE compound formed by the combination of an acid 
 with an alkali, an earth, or a metallic oxide, is called a 
 salt. 
 
 The term neutral salt, was formerly given to all com 
 binations of acids and alkalies, but the epithet neutral 
 is now restricted to those salts in which the acid and the 
 alkali completely saturate each other, and in which, 
 therefore, the peculiar properties of neither can be 
 detected. 
 
 When a salt contains an excess cf acid, its state is 
 indicated by the addition of the word super ; and some- 
 times by the term acidulous; but the latter mode of 
 denoting the distinction, is yielding to the former. 
 
 When the salt contains an excess of alkali, the pre- 
 position sub is prefixed to its name, or the epithet of 
 alkalinous; but the first-mentioned addition is the most 
 general and appropriate. 
 
 The base or radical of a salt, is the alkali, the earth, 
 or metallic oxide, which is combined with the acid. 
 
 Agreeably to the principles which are adopted in 
 forming the new nomenclature, every salt receives a 
 compound name, denoting its base, and the acid which 
 enters into its composition. Thus, the chemical name 
 of common salt is muriate of soda, as it is a combination 
 of muriatic acid and soda. Salt-petre is called nitrate 
 of potass ; because it is a combination of potass and ni- 
 tric acid. Glauber's salt is called sulphate of soda, as it 
 is a combination of soda with sulphuric acid ; and the 
 salts formed by all other acids are reduced to the same 
 form of expression. 
 
 When an acid is combined with two bases, the com- 
 pound is called a triple salt, and both the bases are ex- 
 pressed : thus, we have the tartrate of potass and soda. 
 A single base, combined with two acids, is denoted with 
 equal precision ; thus, we have the nitro-muriate of tin 
 18*
 
 210 CHEMISTRY. 
 
 When the epithet which distinguishes the acid of a 
 salt terminates in ate, it signifies that the epithet of the 
 acid itself terminates in ic ; thus, the sulphuric acid 
 forms sulphates. When the epithet of the salt termi- 
 nates with ite, that of the acid itself terminates in ous ; 
 thus, the sulphurous acid forms sulphites. Most of the 
 salts ending in ite, extract oxygen from the atmosphere, 
 and are converted into the former kind. 
 
 The salts form a very numerous class of bodies. Four 
 croy reckons that there are 134 species; and the number 
 belonging to each species is often considerable. There 
 can scarcely be less than 2000 distinct salts ; but I shall 
 only notice some of the most useful. 
 
 SULPHATES. 
 
 THE sulphates are in general crystallizable, have 
 some taste, but no smell; are precipitated by solution of 
 barytes, and afford sulphurets when heated red-hot with 
 charcoal. They are numerous, as the sulphuric acid 
 combines with all the alkalies, and nearly all the earths 
 and metallic oxides. 
 
 SULPHATE OF ALUMINE. 
 
 SULPHATE of alumine is formed by dissolving alumine 
 in sulphuric acid. It has an astringent taste, is very 
 soluble in water, and crystallizes in thin plates, which 
 have very little consistence. It generally contains an 
 excess of acid. 
 
 I should have omitted the mention of this salt, but to 
 distinguish it from the following one, to which the same 
 name is apt tc be given.
 
 SULPHATES OP ALUMINE AND SODA. 211 
 
 SULPHATE OF ALUMINE AND POTASS, OR 
 AMMONIA, (ALUM.) 
 
 THIS salt is the common alum of commerce. It has 
 an austere, sweetish, astringent taste, and always reddens 
 tincture of litmus. Seventy-five parts of boiling water 
 dissolve 100 of alum, at the temperature of 60; it is 
 soluble in from 10 to 15 times its weight of cold water, 
 the purest alum having the least degree of solubility. 
 Its crystals are large. By exposure to the air it slightly 
 effloresces. Its specific gravity is 1.7. 
 
 According to Vanquelin, alum contains of alumine 
 10.50, sulphuric acid 30.52, potass 10.40, water 48.58. 
 
 Two kinds of alum are found in commerce, the com- 
 mon and rock alum. The latter has a reddish tinge, 
 from an admixture of rose-coloured earth ; it is also the 
 most esteemed, and sold at the greatest price, though the 
 cause of its superiority is not well known. 
 
 The uses of alum are very extensive. In dyeing it is 
 of considerable importance for fixing several vegetable 
 colours. It is used in the tanning of leather, to give 
 firmness to the skins, after they have been in the lime- 
 pits, and in the manufacture of candles, to give consistence 
 to the tallow. Alum may also be used to advantage in 
 the manufacture of writing-paper, to make the paper 
 bear ink better. 
 
 Alum is prepared in France by '.ne artificial combina- 
 tion of its component parts; but in Great Britain it is 
 obtained from a kind of slate, called alum-slate, which 
 is plentiful on the north-east coast of Yorkshire, and near 
 Glasgow ; about 100 tons of the slate only afford 10 tons 
 of alum. 
 
 Ammonia will contribute to the formation of alum as 
 well as potass. 
 
 SULPHATE OF SODA, (GLAUBER'S SALT.) 
 
 THE sulphate of soda has a strongly saline and bitter 
 taste; it* crystals are transparent, but they effloresce 
 and fall into a white powder in the air ; it is soluble in
 
 212 CHEMISTRY. 
 
 rather less than three times its weight of water at the 
 temperature of 60, and in T 8 ^ths of its weight of boiling 
 water. It is principally used in medicine as a purgative, 
 under the name of Glauber's salts. According to Kirwan, 
 it contains of acid 22 parts, soda 17, and water 61. 
 
 GREEN SULPHATE OF IRON, (COPPERAS.) 
 
 THIS salt is the copperas or green vitriol of commerce. 
 Its crystals are of a beautiful light-green ; it has a sharp 
 astringent taste, and is poisonous. It is soluble in 6 
 times its weight of water at the temperature of 60, and 
 in f of its weight of boiling water. It is insoluble in 
 alcohol. According to Bergman it contains of acid 39 
 parts, green oxide of iron 23, and water 38. It is efflo- 
 rescent. 
 
 Green sulphate of iron is obtained by the decomposi 
 tion of pyrites or native sulphuret of iron ; and this 
 decomposition is effected by simple exposure to air and 
 moisture. This salt is much used in dyeing blacks and 
 other intermediate colours, both wool and cotton, also, 
 for the black or iron liquor of the calico printers ; like- 
 wise in preparing writing ink ; and by bookbinders for 
 staining black the skins which have been tanned with 
 oak bark. 
 
 RED SULPHATE OF IRON. 
 
 IF nitric acid be distilled of the green sulphate of iron, 
 or the solution of this salt be exposed to the air, the red 
 sulphate of iron is obtained. It is deliquescent, uncrys- 
 tallizable, and soluble in alcohol. Proust observes that 
 it alone forms prussian blue with prussic acid, and strikes 
 a black colour with gallic acid ; and therefore, when 
 these effects are obtained by operating with the green 
 sulphate, the latter salt has derived from the atmosphere, 
 or some other source, the additional quantity of cxygen 
 necessary to convert its iron to the state of red^xide.
 
 SULPHATE OF COPPER, NITRATE OF POTASS. 213 
 
 SULPHATE OF COPPER, (BLUE VITRIOL OR 
 BLUE COPPERAS.) 
 
 THE crystals of this salt, which were formerly called 
 *ue vitriol, are a fine deep blue. It has a strong styptic 
 taste ; insoluble in four times its weight of water, and 
 effloresces in the air. Its specific gravity is 2.2. U is 
 generally obtained by evaporating the water of copper- 
 mines. 
 
 The sulphate of copper is employed as a caustic, to 
 remove the flesh of fungous ulcers. It is dangerous to 
 administer it internally. It is also employed in dyeing 
 certain colours. 
 
 SULPHITES. 
 
 SULPHITES have a disagreeable sulphurous taste. If 
 exposed to the fire, they yield sulphur, and are converted 
 into sulphates, and even by mere exposure to the atmo- 
 sphere, the same change is produced. They are also 
 decomposed by the nitric, muriatic, and other acids which 
 do not affect sulphates. They are mostly formed ar- 
 tificially. 
 
 The principal sulphites are those of potass, soda, 
 ammonia, alumine, magnesia, and barytes ; none of these 
 have been applied to purposes of any importance. 
 
 NITRATES. 
 
 THE nitrates are soluble in water, and crystallizable , 
 they deflagrate violently when heated to redness with 
 charcoal, or other combustibles ; sulphuric acid disen- 
 gages from them a white vapour of nitric acid. By heat 
 they are decomposed, and yield at first a considerable 
 quantity of oxygen gas. 
 
 NITRATE OF POTASS, (SALTPETRE.) 
 
 NITRATE of potass, saltpetre, or nitre, is the b*t known 
 and most important of all the nitrates. Its tast '** j%*? p,
 
 214 CHEMISTRY. 
 
 bitterish, and cooling. It is very brittle. Its specific 
 gravity is 1.9. It is soluble in seven times its weight of 
 cold water, and in rather less than its weight of boiling 
 water. When mixed with one-third of its weight of 
 charcoal, and thrown into a red-hot crucible, or when 
 charcoal is thrown upon red-hot nitre, the combustion 
 that ensues is exceedingly vivid and beautiful. The 
 residuum is carbonate of potass. The combustion is still 
 more violent, when phosphorus is used instead of char- 
 coal. 
 
 According to Kirwan, nitre contains acid 41.2 parts, 
 potass 46.15, water 12.65. All the nitric acid employed 
 in the arts, is furnished by the decomposition of this salt. 
 The sulphuric acid is employed to effect the decomposi- 
 tion. Considerable quantities of nitre are also used in 
 obtaining sulphuric acid, as it supplies the oxygen for the 
 combustion of sulphur in close chambers. The manufac- 
 ture of gunpowder also requires an immense quantity. 
 
 A considerable part of the nitrate of potass consumed 
 in Europe, is furnished by the East Indies, where the 
 soil, being impregnated with it, yields it by lixiviation 
 and evaporation. At Apulia, near Naples, also, there is 
 a natural nitre-bed, in which the earth contains 40 per 
 cent, of nitre. In Germany, France, and Switzerland, 
 artificial nitre-beds are formed, by suffering animal and 
 vegetable matters to putrefy in combination with calca- 
 reous and other earths. A soil of this kind attracts the 
 nitric acid from the atmosphere. Old mortar furnishes 
 a very proper calcareous earth for a nitre-bed. 
 
 NITRATE OF SODA, (CUBIC NITRE.) 
 
 THIS salt was formerly called cubic nitre, from its 
 crystallizing rhombs. It is somewhat more bitter than 
 the nitrate of potass, rather more soluble in cold water, 
 but much less soluble in hot water. It is not of any 
 important use, though Proust observes, that when made 
 into gunpowder, it burns longer than common nitre, and 
 might therefore be economically adopted for fire-works.
 
 NITRATE OF AMMONIA, MURIATES. 215 
 
 NITRATE OF AMMONIA. 
 
 NITRATE of ammonia has a sharp, acrid, and somewhat 
 urinous taste ; it deliquesces in the air, and is soluble ir 
 about half its weight of boiling water The only ust 
 niade^of it is to furnish nitrous oxide. 
 
 MURIATES. 
 
 THOUGH the muriates are the most volatile of the salts, 
 they are at the same time the least decomposable : they 
 may be melted and volatilized without undergoing decom- 
 position. They effervescewithsulphuric arid, and white 
 acrid fumes of muriatic acid are disengaged; when acted 
 upon by nitric acid, oxymuriatic gas is disengaged. 
 
 MURIATE OF SODA, (COMMON SALT.) 
 
 MURIATE of soda, or common salt, is too well known to 
 require any description. It is the only substance to 
 which the term salt was formerly applied. Besides the. 
 immense quantity of it held in solution by the sea-water 
 it exists in prodigious masses in the state of rock-salt. 
 Its specific gravity is 2.12; and it is soluble in rather 
 less than three times its weight of water. When pure, 
 it is not affected by the air ; but common salt is deliques- 
 cent, from the magnesia and other impurities which it 
 contains. 
 
 Muriate of soda contains of acid 44 parts, soda 50, 
 and of water 6. 
 
 MURIATE OF POTASS, (SALT OF FEBRIFUGE.) 
 
 THIS salt was formerly called febrifuge salt of Sylvius, 
 and regenerated sea-salt. It has a disagreeable, bitter 
 taste; its specific gravity is 1.8; it is soluble in three 
 times its weight of cold water, and twice its weight of 
 boiling water. When heated, it first decrepitates, then 
 melts, and at last is volatilized without decomposition. 
 According to Kirwan, it contains of acid 36 parts, potasa 
 46, and water 18
 
 216 CHEMISTRY. 
 
 MURIATE OF AMMONIA, (SAL AMMONIAC.) 
 
 MURIATE of ammonia, or sal ammoniac, has an acrid, 
 ur.nous taste, an opaque white colour, and a specific 
 gravity of 1.4. It dissolves in three times its weight of 
 cold water. It contains, according to Kirwan, 35 parts 
 of acid, 30 of ammonia, and 35 of water. 
 
 Muriate of ammonia is employed for brightening some 
 colours in dyeing and mixing of colours ; also for pre- 
 serving the surfaces of metals from oxidation in tinning; 
 in medicine it forms an excellent diaphoretic and febrifuge, 
 and has been advantageously applied externally as a 
 lotion for ind jlent tumours. 
 
 HYPER-OXYMURIATE OF POTASS. 
 
 IF a solution of potass bo saturated with oxymuriatic 
 acid gas, and then evaporated in the dark, the first 
 crystals formed are those of common muriate of potass ; 
 when these are separated, and the solution allowed to 
 cool, the crystals of the hyper-oxy muriate of potass are 
 obtained. These crystals have a silvery lustre, and are 
 insipid and cool to the taste. They are soluble in 17 
 parts of cold water, and 2^ of boiling water. 
 
 The hyper-oxymuriate of potass, when mixed with 
 charcoal and other combustibles, and heated, detonates 
 with extreme violence. It also explodes when triturated 
 in a mortar, or when struck with a hammer, if a small 
 quantity of it is laid upon an anvil. 
 
 This salt consists of hyper-oxy muriatic acid 58 parts, 
 potass 39, water 3. The oxygen is about equal to the 
 salt in weight. It was called simply oxymuriate of potass 
 till Chenevix proved that the acid which enters into its 
 composition is in the highest state of oxygenizement. 
 He endeavoured to obtain this acid separately, but the 
 retort containing the salt was reduced almost to powder 
 by a violent explosion. The hyper-oxymuriatic acid has 
 therefore never been exhibited separately.
 
 CARBONATES, FLUATES. 217 
 
 CARBONATES. 
 
 CARBONATES effervesce and yield carbonic acid, when 
 sulphuric or nitric acid is poured upon them; all the 
 alkaline carbonates are soluble in water, while those of 
 the earths and metals are nearly insoluble, unless the 
 acid be in excess. 
 
 SUB-CARBONATE OF POTASS. 
 
 THE potass of commerce is always in the state of 
 sub-carbonate ; the carbonic acid considerably weakens 
 its alkaline properties, yet it will still change vegetable 
 colours to green, and, combined with oils, will form an 
 imperfect soap. 
 
 SUB-CARBONATE OF SODA. 
 
 THE soda of commerce is in the state of sub-carbonate , 
 but its carbonic acid deprives it of more of its alkaline 
 properties than it does potass. For making glass, it is 
 used in the state of a sub-carbonate, because the heat is 
 exposed to drive off the carbonic acid; but to form soap, 
 it must be rendered caustic, which is effected by quick- 
 
 
 lime. 
 
 CARBONATE OF LIME. 
 
 CARBOMC acid has the power of completely neutrali- 
 zing the alkaline properties of lime, which it reduces to 
 a state in which it is nearly tasteless. Under the name 
 of chalk, marble, and limestone, we shall notice this 
 compound. 
 
 FLUATES. 
 
 THE fluates are not decomposed by heat, nor altered 
 
 by combustibles : when sulphuric acid is poured upon 
 
 them, they yield acrid vapours of fluoric acid, which 
 
 corrodes glass. When reduced to powder, and heated 
 
 19
 
 218 CHE3IISTRY. 
 
 but not made red-hot, some of them become phospho- 
 rescent. 
 
 The principal fluoric salts are the fluates of lime, of 
 soda, of potass, of ammonia, of barytes, of alumine, of 
 silex, and of strontian; but this acid forms fluates with 
 mercury, copper, tin, iron, nickel, and several other 
 metals. The whole of the fluates are factitious salts 
 except those of lime and alumine. 
 
 FLUATE OF LIME. 
 
 FLUATE of lime is, in England, well known under the 
 name of Derbyshire spar, or Blue John,. It is tasteless, 
 and nearly insoluble in water. It is not altered by the 
 air. Its specific gravity is 3.1. When powdered, and 
 heated upon a shovel, it emits a violet-coloured light ; 
 but this ceases if it be made red-hot. It is fused by a 
 strong heat, and is occasionally used as a flux. It exists 
 in the enamel of the human teeth. 
 
 FLUATE OF SILEX. 
 
 THE fluoric acid gas will dissolve silex, and still re- 
 tains its aerial form ; but the silex is afterwards deposited 
 in crystals. 
 
 BORATES. 
 
 THE Borates are all fusible into glass, and assist the 
 fusion of other bodies, particularly metals, and metallic 
 oxides ; with the metallic oxides, they form glass of dif- 
 ferent colours. 
 
 The principal salts of this class, are the sub-bora te of 
 vculu. the borate of potass, of lime, of magnesia, and of 
 ulumine. 
 
 SUB-BORATE OF SODA, (BORAX.) 
 
 THIS is the only borate of any importance. It is dug 
 ;mt of wells in the kingdom of Thibet, and comes to us 
 from the East Indies. It is then in a state of impurity, 
 and is called tincal ; when purified, it receives the name
 
 ACETATES OF POTASS AND AMMONIA. 219 
 
 of borax. It is in whitish crystals, has a styptic and 
 alkaline taste, and converts vegetable blues to green. It 
 is soluble in twenty times its weight of cold water, and 
 six times its weight of boiling water. When melted into 
 glass, it is transparent, and still soluble in water. When 
 two pieces of borax are 'struck together in the dark, a 
 flash of light is emitted. Its specific gravity is 1.740, It 
 slightly effloresces in the air. 
 
 According to Bergman, this salt consists of 39 parts 
 of boracic acid, 17 of soda, and 44 of water. It is much 
 used as a flux in soldering metals with the hard solders. 
 
 ACETATES. 
 
 THE acetic salts are distinguished by their great solu- 
 bility in water ; by the decomposition of the acid when 
 the solution is exposed to the air; by their being decom- 
 posed by heat, and by their yielding acetic acid when 
 mixed with sulphuric acid, and distilled. 
 
 The principal acetates are those of potass, of soda, of 
 ammonia, of magnesia, of barytes, of lead, and of copper. 
 
 ACETATE OF POTASS. 
 
 THIS salt has been long known, and has been distin- 
 guished by almost a dozen different names : of which one 
 was secret foliated earth of tartar. It has a sharp 
 warm taste; its crystals are white, and in the form of 
 thin plates. It is soluble in alcohol, in ten times its 
 weight of water, and is deliquescent. It is used in medi- 
 cine. It was formerly made from distilled or even com- 
 mon vinegar, but is now manufactured from pearl-ash 
 and purified pyroligneous acid. 
 
 ACETATE OF AMMONIA. 
 
 THIS salt tastes like a mixture of sugar and nitre. Jf 
 is extremely volatile; and cannot be crystallized, except 
 by an extremely slow evaporation. Its crystals are long 
 and slender, and of a pearl-white colour. It is deliques- 
 cent. Its solution has been long used medicinally under 
 the name of spirits of Mindererus.
 
 220 CHEMISTRY. 
 
 ACETATE OF LEAD, (SUGAR OF LEAD.) 
 
 THIS salt is formed by the solution of the white oxide 
 of lead in the acetic acid. It has a sweet and somewhat 
 astringent taste ; and is sparingly soluble in water. It 
 becomes yellow by exposure to the air. Like all other 
 preparations of lead, it is a strong poison, but in doses of 
 a very few grains, it has been administered, with evident 
 advantage, in desperate cases of internal hemorrhage. 
 Its solution in water is used internally as an embrocation. 
 That decomposes it It is used considerably by the 
 calico-printers in colour-making, &c. 
 
 ACETATE OF COPPER. 
 
 ACETATE of copper has a disagreeable, coppery taste ; 
 a fine deep green colour, some degree of unctuosity, is 
 efflorescent, and is soluble in water and alcohol. It is 
 used in dyeing: a small quantity of it does very well in 
 writing-ink. It is also used in painting. In chemistry, 
 it is distilled for the acetic acid it affords. 
 
 TARTRATES. 
 
 THE tartrates are decomposed by a red heat. The 
 earthy tartrates are less soluble than the alkaline; but 
 they are all capable of combining with another base, and 
 forming triple salts. 
 
 The principal tartrates are those of potass, of potass 
 and -soda, of potass and ammonia, of lime, of strontian, 
 and of potass and antimony. 
 
 SUPER-TARTRATE OF POTASS 
 
 Is the cream of tartar of the stores. It has a strong', 
 but not disagreeable acid taste'; is soluble in thirty times 
 its weight of boiling water; and is not altered by the ex- 
 posure to the air. According to Bergman, it contains 23 
 parts of potass, and 77 of acid. It is used in medicine 
 as a mild aperient It is also useful in dyeing.
 
 TARTRATES, PHOSPHATES. 221 
 
 TARTRATE OF POTASS AND SODA. 
 
 THIS triple salt is sold by the druggists under the 
 name of Rochelle salts. It has a strongly saline bitter 
 taste ; is effervescent, and is soluble in about four times 
 its weight of cold water. It is a mild cathartic 
 
 TARTRATE OF POTASS AND ANTIMONY 
 
 THE crystals of this triple salt are of a white colour, 
 and transparent. It is soluble in 60 parts of cold water. 
 It is formed by precipitating the muriate of antimony 
 with a hot solution of potass in distilled water. The 
 precipitate being well washed and dried, nine drachms 
 are to be boiled in five pounds of water, with two ounces 
 and a half of super-tartrate of potass, finely powdered, 
 till the powders are dissolved. The solution must then 
 be strained, evaporated to a pellicle, and left to crystallize. 
 In doses of from two to four grains, this is the best and 
 most powerful emetic known. 
 
 PHOSPHATES. 
 
 THE phosphates are capable of vitrification ; are par- 
 tially decomposed by sulphuric acid ; are phosphorescent 
 at a high temperature ; are soluble in nitric acid, without 
 effervescence ; and may be precipitated from their solu- 
 tions by lime-water. 
 
 The principal phosphates are those of potass, of soda, 
 of ammonia, of lime, and of magnesia. 
 
 PHOSPHATE OF SODA. 
 
 THE phosphate of soda has nearly the same taste as 
 common salt ; it is soluble in water, and efflorescent. As 
 a cathartic, it is equivalent to Glauber and Rochelle 
 salts, and as its taste is much pleasanter, it has been used 
 instead of those well-known medicines. It may be ad- 
 ministered bjr dissolving in a weak broth, to which it 
 19*
 
 222 CHEMISTRY. 
 
 serves as an agreeable seasoning. Dr. Pearson first pre 
 pared and introduced it. It is used in the arts as a flux 
 instead of borax. 
 
 PHOSPHATE OF SODA AND AMMONIA. 
 
 THIS compound, which \vas formerly called nicrocomic 
 salt, is much used as a flux in assays with the blowpipe. 
 It may be obtained from human urine by evaporation. 
 
 PHOSPHATE OF LIME. 
 
 PHOSPHATE of lime is white, tasteless, and insoluble in 
 water. As it forms the bases of bones, it has been some 
 times called the earth of bones. It exists in milk, and 
 some bther animal products, also in wheat. In Spain it 
 has been found abundantly in the fossil state. 
 
 PRUSSIATES. 
 
 THE singular affinities of some prussiates render them 
 interesting to the chemist; the simple prussiates are, 
 however, little regarded, because destitute of permanen- 
 cy, being decomposed merely by exposure to the air, 
 unless united with a metallic oxide. The prussic acid 
 does not appear capable of saturating an alkali; and 
 the weakest acid known is capable of decomposing the 
 prussiates of the earths and the alkalies. 
 
 The most important of the simple prussiates is that of 
 iron ; and of triple prussiates, those of potass, soda, lime, 
 and ammonia with iron. 
 
 PRUSSIATE OF IRON. 
 
 THE prussiate of iron, or prussian blue, is, according 
 to Proust, a combination of the prussic acid and red 
 oxide of iron. With the green oxide, the prussic acid 
 forms a white compound, which, however, becomes 
 gradually blue by exposure to the atmosphere, from the 
 absorption of oxygen. It is a fine deep blue, and valua- 
 ble as a pigment ; it is insoluble in water, very sparingly
 
 PRUSSIATES, OXIDES. 223 
 
 soluble in acids, and not affected by exposure to the air 
 It is composed of equal parts of the acid and the oxide, 
 If exposed to a strong heat, the acid is destroyed, and 
 the residuum is simply oxide of iron. If the blue prus- 
 siate of iron be deprived of part of its acid, by digesting 
 it with alkalies, it becomes yellowish. 
 
 PRUSSIATE OF POTASS AND. IRON. 
 
 THIS compound is often called prussian alkali, or prus- 
 sian test. The importance of it to chemists, consists in 
 its being capable of indicating whether a metal be pre- 
 sent in any solution whatever, unless the metal be pla- 
 tina ; and the colour of the precipitate differing with the 
 metal, even the name of the metal may be known. It 
 is necessary to take great care to have it perfectly pre- 
 pared, otherwise it will afford false results. We have 
 gi/en Henry's directions respecting its preparations under 
 the head of prussic acid. Its crystals should be well pre- 
 served in a well stopped bottle filled with alcohol in 
 which they are insoluble. 
 
 OF OXIDES. 
 
 WHEN the oxygen united to any of the simple sub- 
 stances does not give it the properties of an acid or an 
 alkali, the compound is called an oxide. 
 
 Most of the metals are capable of combining with dif- 
 ferent proportions of oxygen, and a difference in the pro- 
 portion of oxygen gives a different colour to the oxide. 
 
 Some oxides require only an additional quantity of 
 oxygen to convert them into acids; others always retain 
 the character of oxides, whether possessed of the highest 
 Or the lowest quantity with which they will combine. 
 
 Oxides cannot be formed except oxygen be present, 
 and the oxide of any substance is heavier than the sub- 
 stance itself, by a quantity exactly equal to the oxygen 
 received. The young student mav be reminded, that by 
 the term heavier, it is not meant that the density or
 
 224 CHEMISTRY. 
 
 specific gravity of the oxide is greater than its base, but 
 the total quantity of it weighs more. 
 
 Oxides are in general friable or pulverulent, and have 
 the appearance of earths ; but one of them is a fluid, 
 and some of them are gases. 
 
 OXIDES OF NITROGEN. 
 
 NITROGEN combines in two proportions with oxygen, 
 without producing an acid. It therefore furnishes two 
 oxides, which are distinguished from each other, like the 
 acids, by a difference in the termination of the word 
 denoting the base ; they are the nitrous oxide and nitric 
 oxide. 
 
 Nitrous oxide. This gas, which is also known by the 
 name of gaseous oxide of nitrogen, is composed of 63 
 parts of nitrogen, and 37 of oxygen by weight. It has 
 a faint smell, and imparts a slight sensation of sweetness, 
 when respired. It is dissolved by water ; but may be 
 expelled from the water by heat unchanged. Alcohol 
 absorbs more of it than water, and the essential and 
 fixed oils more than alcohol ; but heat expels it from all 
 these combinations. It supports combustion with more 
 activity than common air ; but it is, in general, necessary 
 that the combustible should be kindled in the atmosphere 
 or oxygen. It may be respired for a few minutes ; and 
 the extraordinary effects it produces on the system, du- 
 ring its respiration, and for a short time after, occasions 
 it to be frequently made for this purpose, which is the 
 only use, (if it may be called use,) to which it may be 
 applied. To inhale it superinduces a species of intoxica- 
 tion : the mind of the person is lost for a moment to a 
 right consciousness of things around him. In general, he 
 laughs involuntarily and extravagantly; exhibits the 
 most frantic or preposterous gesticulations, and violent 
 muscular exertion, and feels, at the same time, delight- 
 fully happy. In a few moments, after having ceased tc 
 breathe the gas, its effects go off With nearly all per 
 sons who have breathed this gas, not the least uneasi- 
 ness or languor subsequently remains; it has even re
 
 OXIDES OF NITROGEN. ' 225 
 
 covered some from a state of casual debility, and restored 
 them to comfortable enjoyment ; but, as there are others 
 on whom less favourable effects have been produced, it 
 may be a useful caution for those who have nevei 
 breathed it, or who are not in perfect health, to take, 
 in the first instance, but a small dose. 
 
 As it is important that the nitrous oxide intended to 
 be inhaled should be perfectly pure, it may be proper to 
 observe, that it can only be prepared with certainty by 
 the decomposition of nitrate of ammonia. For this pur- 
 pose, nitric acid, diluted with five or six parts of water, 
 may be saturated with carbonate o/ ammonia, and the 
 solution evaporated by a gentle heat, adding, occasion- 
 ally, a little of the carbonate, to supply what is carried 
 off The nitrate crystallizes in a fibrous mass, unless the 
 evaporation has been carried so far as to leave it dry 
 and compact. 
 
 The nitrate should be put into a retort, and a lamp 
 furnace should be employed to decompose it ; as the heat 
 employed should not be raised above 450. A pound 
 of the nitrate of ammonia will yield about 5 cubical 
 feet of the gas, which should be received over water, 
 and afterwards allowed to stand an hour or two in con- 
 tact with the water, which will absorb any ammonia 
 that may have been sublimed, or any acid that may 
 happen to be present. 
 
 Nitric oxide, (sometimes called nitrous gas.) This 
 gas is composed of 44 parts of nitrogen, and 56 of oxygen 
 by weight. It is an invisible gas, until it comes in con- 
 tact with the atmosphere, or some air which contains 
 oxygen, when it assumes an orange colour. It is interest- 
 ing to observe the difference between this gas, and the 
 preceding, from which it only differs in containing a few 
 parts more oxygen ; this gas instantly kills the animals 
 which breathe it ; and even destroys plants. In general, 
 also, it extinguishes light, but some substances have the 
 property of decomposing it, if inflamed before being put 
 tfito it, and of then burning with considerable splendour. 
 
 Dr. Priestley found that water was capable of absorb-
 
 226 * CHEMISTRY. 
 
 ing about one tenth of nitric oxide, from which it ac- 
 quired an astringent taste ; and that the water gave out 
 the whole of this gas when passing to the state of ice. 
 Oils greedily absorb nitric oxide, and decompose it 
 Nitric acid also absorbs it, and is converted by the 
 absorption into nitrous acid, becoming fuming and col- 
 oured at the same time. 
 
 Nitric acid is composed of 75 parts of oxygen and 25 
 parts of nitrogen ; it, therefore, bears a very near rela- 
 tion to this gas, which may be converted into it, by sim- 
 ply mixing it with a due proportion of oxygen. 
 
 OXIDE OF HYDROGEN. 
 
 HYDROGEN appears to be capable of combining with 
 oxygen only in one proportion, and that one forms water, 
 which is the oxide of hydrogen. 
 
 CARBONIC OXIDE. 
 
 CARBOX, combined with 60 per cent, of oxygen, forms 
 carbonic oocide, which is an invisible and elastic gas, of 
 rather less specific gravity than common air. This gas 
 is not fit for respiration, nor will it support combustion ; 
 but it will itself burn, with a lambent blue flame, in 
 atmospheric air. This is the only oxide of carbon which 
 has been obtained. 
 
 OXIDE OF SULPHUR. 
 
 SULPHUR, if kept for some time in fusion in an open 
 vessel, absorbs about 2.4 per cent, of oxygen. This is 
 the only oxide of it which is known ; it is of a red colour, 
 and is used for taking impressions of metals. 
 
 OXIDE OF PHOSPHORUS 
 
 THE brown colour which phosphorus acquires by ex- 
 posure to the air, is in consequence of its combination 
 with oxygen, and this brown part is the oxide of phos- 
 phorus. Phosphorus when mixed with its oxide, which 
 it generally is when newly prepared, may be purified by 
 putting i* into hot water ; the oxide swims on the surface.
 
 METALLIC OXIDES. 227 
 
 METALLIC OXIDES. 
 
 METALLIC oxides are exceedingly numerous; every 
 metal is capable of forming at least one oxide, and most 
 metals are capable of forming several by combining with 
 different proportions of oxygen. The oxygen which en- 
 ters into their composition, has the singular effect of 
 depriving them entirely of their lustre and cohesion, and 
 reducing them to the state of earths. 
 
 An acid has no action upon a metal, unless the oxygen 
 it contains has a greater attraction for the metal put into 
 it, than for the base of the acid. The acids first impart 
 oxygen to metals, and then dissolve the oxide. 
 
 The metals, in the readiness with which they imbibe 
 oxygen, and the firmness with which they retain it, differ 
 very considerably. From some, as manganese, it cannot 
 be separated without difficulty; from others, as gold, 
 silver, and platina, it is ever ready to separate, because 
 of their slight affinity for it, which constitutes their dis- 
 position to resume their metallic state, and is the leading 
 property of what are called noble metals. 
 
 From the beauty and fixedness of the colours of many 
 of the metallic oxides, they are used as pigments in 
 painting in oil and water colours ; and as they are con- 
 vertible into glass, they are admirably adapted for painting 
 on enamel and porcelain. A purple colour is given by 
 gold; yellow by silver: green by copper; red by iron; 
 blue by cobalt ; and violet by manganese. 
 
 As carbon and hydrogen have a stronger attraction for 
 oxygen than other substances, they, or the substances 
 consisting chiefly of them, are employed for reducing 
 metallic oxides; the metallic oxide is mixed up with 
 charcoal, oil, fat, resin, or the cheapest inflammable body 
 which can be obtained, and submitted in a crucible to 
 strong heat; the oxygen of the oxide combines with tl.e 
 hydrogen or carbon which is present, and the metal 
 is obtained in its metallic state at the bottom of the 
 crucible
 
 228 CHEMISTRY. 
 
 ORGANIC SUBSTANCES 
 
 VEGETABLES. 
 
 VEGETABLES, though infinitely diversified in their ap- 
 pearance and properties, are found to consist of a smal 
 number of simple substances ; carbon is the basis of them 
 11, and after carbon, hydrogen and oxygen may be con- 
 idered as forming the principal part of them. Some 
 vegetables contain nitrogen, others phosphorus, earths, 
 and metals, but these elements *are not general ; they 
 belong only to particular plants, or to plants in particulai 
 situations. 
 
 Although the proportions of the component parts of 
 vegetables may be ascertained with considerable accu 
 rucy, yet the chemist is unable to combine these com 
 ponent parts in any manner that shall produce substan 
 ces resembling the entire vegetable, or the compounded 
 products which it affords. 
 
 Plants derive a principal part of their nourishment 
 from water ; their roots imbibe the water, which is 
 decomposed in them, by the assistance of light and heat , 
 and a part of its hydrogen becomes fixed, while a part, 
 at least, of the oxygen is given out by transpiration 
 Water will hold carbon in solution, deriving it from the 
 soil; and hence the utility of dung, or putrefying animal 
 or vegetable substances, which supply a large quantity 
 of carbon, as well as hydrogen and nitrogen. Plants 
 will grow, although their roots stand in such materials 
 as lose no portion of their weight, and although they be 
 watered with distilled water. In this case, the carbon 
 of the plants is derived from the atmosphere, through the 
 medium of the leaves. Perhaps, at all times, the atmo- 
 sphere furnishes a part of the carbon, through the 
 medium of the under-surface of the leaves; but when 
 an adequate supply is derived from the roots, the leaves 
 perform this rffice with less energy. Water impreg-
 
 ORGANIC SUBSTANCES. U29 
 
 nated with carbonic acid gas, renders vegetation more 
 vigorous. 
 
 The processes of vegetation have a considerable ten- 
 dency to produce equality of temperature. If the bulb 
 of a thermometer be plunged into a hole in a tree, it 
 indicates a higher temperature than the atmosphere in 
 cold weather, and a lower temperature in hot weather. 
 
 The most usual compound substances, furnished by 
 vegetables, and which are possessed of remarkable or 
 distinct characters, we shall consider separately. 
 
 SUGAR. 
 
 SUGAR is afforded by most plants, and in some, such 
 as the sugar-cane, the beet-root, the sugar-maple, the 
 carrot, it is particularly abundant. It crystallizes, is 
 sweet to the taste, and soluble in water and alcohol. 
 Used as food, it is extremely nourishing and antiseptic, 
 Treated with nitric acid, it affords oxalic acid. Lime 
 barytes, magnesia, and strontian, are soluble in the solu- 
 tion of sugar. One hundred parts of sugar, contain of 
 carbon 28 parts, of hydrogen 8, and of oxygen 64. 
 
 STARCH, OR FECULA. 
 
 STARCH is white, insipid, insoluble in cold water or 
 alcohol, but forming with boiling water a semi-transpa- 
 rent jelly. It is abundant in potatoes, wheat, barley, 
 and many other plants, roots, and seeds, and mav be 
 separated from them by maceration in water. It dis- 
 solves in cold water that contains an acid or an alkali. 
 
 Fecula is often used as a general term for all matters 
 contained in the juices of plants, and not held in solution 
 by them ; sometimes we hear of amylaceous fecula 
 this is the same with starch ; green fecula is also an 
 expression in use, but the green colour of fecula is sel- 
 dom permanent. Indigo is a blue fecula. 
 20
 
 230 CHEMISTRY. 
 
 ALBUMEN. 
 
 ALBUMEN is most abundant in those vegetables which 
 ferment and afford a vinous liquor without yeast. It is 
 soluble in cold water ; but its chief characteristic is, that 
 it coagulates and becomes insoluble by heat 
 
 GLUTEN. 
 
 IF wheaten flour be kneaded in cold running water 
 the water will carry off the mucilage and starch it con- 
 tains ; and, when the water runs off colourless, a pecu- 
 liar substance will remain, which is called gluten. 
 
 Gluten composes about one-twelfth of the matter of 
 wheaten flour ; it is ductile and elastic, and of a stringy 
 texture: it has some smell, but no taste. If stretched 
 out, it returns to its original state. By exposure to the 
 air, it becomes brown, and appears to have an oily coat- 
 iBg. When completely dry, it is very brittle, and resem- 
 bles glue. If kept moist, it soon putrefies. It is insoluble 
 in water, alcohol, or ether; but the acids dissolve it, and 
 the alkalies precipitate it No other vegetable product 
 has so near an alliance to animal matter, both in its 
 appearance, which is like "that of tendons, and in its 
 constituent parts, into which nitrogen largely enters, and 
 some ammonia. 
 
 GELATINE. 
 
 GELATINE, or jelly, has some resemblance to albumen, 
 but differs from it in not being coagulated by heat It 
 is soluble in water, insipid, and precipitated by infusion 
 of galls. It may be procured from blackberries, and 
 other fruits of a similar kind. 
 
 BITTER PRINCIPLE. 
 
 THE bitter principle of vegetables is soluble in water 
 and alcohol. It is soluble in nitric acid, and precipitated 
 by nitrate of silver. Its colour is yellow, or brown. Hops, 
 quassia, &c. contain much of it
 
 ORGANIC SUBSTANCES. 231 
 
 NARCOTIC PRINCIPLE. 
 
 THE narcotic principle is soluble in 400 parts of hot 
 water ; alcohol dissolves a twenty-fourth part of it. It 
 is crystallizable, and of a white colour. It is soluble in 
 all the acids without heat, and is precipitated from them 
 in a white powder by alkalies. 
 
 EXTRACTIVE MATTER. 
 
 EXTRACTIVE matter is taken up from vegetables by 
 water and alcohol ; and, therefore, is soluble in these 
 fluids. It is insoluble in ether. It is precipitated by 
 oxymuriatic acid, muriate of tin, and muriate of alumine, 
 but not by gelatine. It dyes a fawn colour. In the 
 roots of liquorice, it is abundant 
 
 TANNIN. 
 
 TANNINT is the name given to the peculiar principle 
 which combines with the gelatine of skins, and converts 
 them into leather. It is found in the gall-nut, and in 
 all vegetables, or parts of vegetables, which are called 
 astringent. It has by some been deemed the astringent 
 principle. It is soluble in water and alcohol, but is pre- 
 cipitated by gelatine, with which it forms an insoluble 
 compound, that becomes solid and elastic. 
 
 WAX. 
 
 WAX is in its composition very analogous to fixed 
 oil. It is a vegetable product : bees are merely the 
 labourers by whom it is collected ; they do not alter its 
 nature. If the nitric or muriatic acid be digested for 
 several months upon a fixed oil, the oil passes to a sub- 
 stance resembling wax. Hence wax might be inferred 
 to be a fixed oil concreted by the absorption of oxygen. 
 Its natural colour is yellow, but it may be whitened by 
 exposing it in thin laminae to the air and sun. Alkalies 
 dissolve wax, and render it miscible with water. 
 
 In China and in North America, wax is obtained di- 
 rectly from plants, and is then called vegetable-wax.
 
 232 CHEMISTRY. 
 
 HONEY. 
 
 HOXEY, like wax, is gathered by bees, ready formefl 
 from flowers, which contain it in an organ called a nec- 
 tary ; it is deleterious when gathered in districts where 
 poisonous shrubs abound, of which there are many ex- 
 amples in the uncultivated parts of America. Honey is 
 composed of sugar, mucilage, and water. 
 
 BIRD-LIME. 
 
 BIRD-LIME is of a greenish colour, has the smell of 
 linseed oil, is insipid to the taste, and is extremely viscid. 
 It is perfectly soluble in ether, sparingly so in alcohol, 
 and insoluble in water. By exposure to the air, it be- 
 comes dry enough to be powdered, but recovers its 
 viscidity by wetting it. It reddens tincture of litmus. 
 
 The best bird-lime is supplied by the middle bark of 
 the holly, which is boiled in water, left to ferment for 
 several weeks, and afterwards macerated in water. 
 
 COLOURING MATTER. 
 
 THE colouring matter of vegetables is combined with, 
 1, the extractive principle ; 2, with resin ; 3, with fecula; 
 4, with gum. Most of the colouring matters of vegeta- 
 bles have a great affinity for the earths, particularly for 
 alumine ; and for the white metallic oxides, especially 
 the white oxide of tin ; also for animal fibrous matters, 
 and for oxygen. On a due regard to these affinities, 
 depends the art of dyeing. 
 
 Berthollet remarks, that those colouring matters which 
 contain the most carbon, afford the richest and most 
 'asting colours. Indigo is of this class. 
 
 WOODY FIBRE. 
 
 WHEN thin shavings of wood are boiled in water, to 
 separate the extractive matter, and afterwards in alcohol, 
 to dissolve the resin, a residuum is obtained called the 
 woody fibre. It constitutes the basis of the solid jpart of 
 vegetables. It is tasteless, insoluble in water or alcohol
 
 ORGANIC SUBSTANCES. 23 o 
 
 but it is soluble in weak alkaline solutions, and is preci|> 
 itated by acids. It is also soluble in nitric acid, and 
 yields oxalic acid. It is not liable to putrefaction by 
 exposure to the air. It consists principally of carbon, 
 and therefore, when burnt in close vessels, affords much 
 charcoal. 
 
 BALSAMS. 
 
 BALSAMS have a strong and fragrant smell : most of 
 them are semi-fluids. When heated, the benzoic acid 
 sublimes from them, which constitutes the principal dis- 
 tinction between them and resins. Like resins, they are 
 obtained by incisions made in the trees affording them. 
 
 RESINS. 
 
 RESINS are mostly insoluble in water, but when pure, 
 they are soluble in alcohol, oils, ether, alkalies, and acetic 
 acid. They are sometimes brittle, sometimes soft and 
 tough, and they all become fluid by heat. The nitric 
 acid converts them into tannin. By distillation, they 
 afford volatile oil. They are all electric, and their 
 electricity is negative. During combustion they afford 
 much smoke. 
 
 MUCILAGE, OR GUM. 
 
 THE mucilage of vegetables is usually transparent, 
 more or less brittle when dry, though difficultly pulvera- 
 ble ; of an insipid, or slightly saccharine taste ; soluble 
 in, or capable of combining with water in all proportions, 
 to which it gives a gluey adhesive consistence, in propor- 
 tion as its quantity is greater. It is separable, or coagu- 
 lates by action of weak acids ; it is insoluble in alcohol, 
 and in oil ; and capable of the acid fermentation, when 
 diluted with water. The destructive action of fire 
 causes it to emit much carbonic acid, and converts it 
 into coal, without exhibiting any flame. Distillation 
 affords water, acid, a small quantity of oil, a small quan- 
 tity of ammonia, and much coal. 
 
 These are the leading properties of gums, rightly so
 
 234 CHEMISTRY. 
 
 called ; but the inaccurate custom of former times ap 
 plied the term gum to all concrete vegetable juices ; so 
 that in common we hear of gum copal, gum sandarach, 
 nd other gums, which are either pure resins, or mixture 
 of resins with vegetable mucilage. 
 
 The principal gums are, 1. the common gums, ob- 
 tained from the plum, the peach, the cheriy-tree, &c. 
 2. Gum-arabic, which flows naturally from the acacia, in 
 Egypt, Arabia, and elsewhere. This forms a clear 
 transparent mucilage with water. 3. Gum-seneca or 
 Senegal. It does not greatly differ from gum-arabic ; 
 the pieces are larger and clearer, and it seems to com- 
 municate a higher degree of the adhesive quality to 
 water. It is much used by calico-printers, and others. 
 The first sort of gums are frequently sold by this name, 
 but may be known by their darker colour. 4. Gum 
 adragant or tragacanth. It is obtained from a smah 
 plant, a species of astragalus, growing in Syria, and 
 other eastern parts. It comes to us in small, white, 
 contorted pieces, resejnbling worms. It is usually dearer 
 than other gums, and" forms a thicker jelly with water. 
 
 GUM ARABIC. 
 
 THE Egyptian thorn yields the true acacia gum, or 
 gum-arabic. Cairo and Alexandria were the principal 
 marts for gum-arabic, till the Dutch introduced the gum 
 from Senegal into Europe, about the beginning of the 
 seventeetth century ; and this source now supplies the 
 greater part of the vast consumption of this article. The 
 tree which yields the Senegal gum grows abundantly on 
 the sands along the whole of the Barbary coast, and par- 
 ticularly about the river Senegal. There are several 
 species, some of which yield a red astringent juice ; but 
 others afford only a pure, nearly colourless, insipid gum, 
 which is the great article of commerce. These trees 
 .ire from eighteen to twenty feet high, with thorny 
 branches. The gum makes its appearance about the 
 middle of November, when the soil has been thoroughly 
 saturated with periodical rains. The gummy juice is
 
 ORGANIC SUBSTANCES. 235 
 
 seen to ooze through the trunk and branches, and, in 
 about a fortnight, it hardens into roundish drops, of a 
 yellowish-white, which are beautifully brilliant where 
 they are broken off, and entirely so, when held in the 
 mouth for a short time, to dissolve the outer surface. No 
 clefts are made, nor any artificial means used by the 
 Moors, to solicit the flowing of the gum. The lumps of 
 gum-senegal are about the size of partridge-eggs, and 
 the harvest continues about six weeks. This gum is a 
 very wholesome and nutritious food ; thousands of the 
 Moors supporting themselves entirely upon it during the 
 time of harvest. About six ounces is sufficient to stipport 
 a man a day ; and it is besides mixed with milk, animal 
 broths, and other victuals. 
 
 Gum-arabic, or that which comes directly from Egypt 
 and the Levant, only differs from the gum-senegal, in 
 being of a lighter colour, and in smaller lumps; and it 
 is, also, somewhat more brittle. In other respects, they 
 resemble each other perfectly. 
 
 GUM SENEGAL. 
 
 SEE Gum-arabic. 
 
 GUM TRAGACANTH. 
 
 WE are indebted to a French traveller, by the name 
 of Oliver, for the discovery, that the gum-tragacanth of 
 commerce, is the produce of a species of astragalus, not 
 before known. He describes it, under the name of as- 
 tragalus verus. It grows in the north of Persia. Gum- 
 tragacanth, or gum-dragon, (which is forced from this 
 plant by the intensity of solar rays, is converted into 
 irregular lumps, or vermicular pieces, bent into a variety 
 of shapes, and larger or smaller proportions, according to 
 the size of the wood from which it issues,) is brought 
 chiefly from Turkey. The best sort is white, semi- 
 transparent, dry, yet somewhat soft to the touch. 
 
 Gum-tragacanth differs from all other gums, in giving 
 a thick consistency to a much larger quantity of water, 
 and in being much more difficultly soluble, or rather
 
 236 CHEMISTRY. 
 
 dissolves only imperfectly. Put into water, it slowly im 
 bibes a great quantity of the liquid, swells into a large 
 volume, and forms a soft, but not fluid mucilage : if more 
 water be added, a fluid solution may be obtained by 
 agitation ; but the liquor looks turbid and whitish, and 
 on standing, the mucilage subsides, the limpid water 
 on the surface retaining little of the gum. Nor does the 
 admixture of the preceding more soluble gums promote 
 its union with the water, or render it dissoluble, or more 
 durable. When gum-tragacanth and gum-arabic are 
 dissolved together in water, the tragacanth separates 
 from the mixture more speedily than when dissolved by 
 itself. 
 
 Tragacanth is usually preferred to other gums for 
 making up torches, and other like purposes, and is sup- 
 posed likewise to be the most effectual as a medicine. 
 
 According to Bucholtz, gurn-tragacanth is composed 
 of 57 parts of a matter similar to gum-arabic, and 43 of 
 a peculiar substance, capable of swelling in cold water 
 without dissolving, and assuming the appearance of a 
 thick jelly. It is soluble in boiling water, and then forms 
 a mucilaginous solution. 
 
 BRITISH GUM. 
 
 WHEX starch is exposed to a temperature between 
 600 and 700 it swells, and exhales a peculiar smell ; it 
 becomes of a brown colour, and in that state is employed 
 by calico-printers. It is soluble in cold water, and does 
 not form a blue compound with iodine. Vanquelin found 
 it to differ from gum in affording oxalic instead of mucous 
 acid, when treated with nitric acid. 
 
 GUM COPAL. 
 
 (THE American name of all clear odoriferous gums.) 
 This resinous substance is imported from Guiana, where 
 it is found in the sand on the shore. It is a hard, shining, 
 transparent, citron coloured, odoriferous, concrete juice 
 of an American tree, but which has neither the solubility 
 in watei common to gums, nor the solubility in alcohd
 
 ORGANIC SUBSTANCES. 237 
 
 common to resins, at least in any considerable degree. 
 By these properties it resembles amber. It may be dis- 
 solved by digestion in linseed oil, rendered drying bv 
 quicklime, with a heat very little less than sufficient to 
 boil or decompose the oil. This solution, diluted with 
 oil of turpentine, forms a beautiful transparent varnish, 
 which, when properly applied, and slowly dried, is very 
 hard and durable. This varnish is applied to snuff 
 boxes, tea-boards, and other utensils. It preserves and 
 gives lustre to paintings, and greatly restores the decayed 
 colours of olckpictures, by filling up the cracks, and ren- 
 dering the surfaces capable of reflecting light more 
 uniformly. 
 
 CAOUTCHOUC OR GUM-ELASTIC. 
 
 GUM-EEASTIC or Indian rubber, possesses great elas- 
 ticity; is soluble in water and alcohol, is reduced to a 
 pulp by heated spirits of turpentine, but is strictly soluble 
 only in nitric ether and naphtha. The solution is ex- 
 tremely adhesive, and slow in drying. 
 
 Caoutchouc always remains soft, like leather, unless 
 in a very low temperature ; it is fusible, and burns like 
 resins, but with less smoke. 
 
 Caoutchouc is prepared chiefly from the juice of the 
 Siphonica elastica. The manner of obtaining this juice 
 is by making incisions through the bark of the trunk of 
 the lower part of the tree, from which the fluid resin 
 issues in great abundance, appearing of a milky white- 
 ness as it flows into the vessel placed to receive it, after 
 which it inspissates into a soft, reddish, elastic resin. It 
 is now manufactured into various articles of wearing 
 apparel, &c. 
 
 GUM-LAC. 
 
 THE improper name of gum-lac is given to a concrete 
 brittle substance, of a dark-red colour, brought from the 
 East Indies, incrustated on the twigs of the Croton Luci- 
 ferum, where it is deposited by a small insect, at p^sent 
 not scientifically known. It is found in great quantities
 
 238 CHEMISTRY. 
 
 on the uncultivated mountains on both sides the Ganges 
 and is of great use to the natives in various works of art) 
 as varnishing, painting, dyeing. &c. When the resinous 
 matter is broken off the wood into small pieces or grains, 
 it is termed seed-lac, and when melted and formed into 
 flat plates, shell-lac. This substance is chiefly employed 
 for making sealing-wax. A tincture of it is recommended 
 as an antiscorbutic to wash the gums. 
 
 GUM RESINS. 
 
 GUM resins are distinguished from common resins by 
 their forming milky solutions with alcohol, and by their 
 being infusible. Their solutions with alcohol are transpa- 
 rent. Frankincense, scamrnony, aloes, and gum ammoniac, 
 are gum resins. Both gum resins and balsams afford 
 tannin when treated with nitric acid. 
 
 TAR. 
 
 .THIS is obtained as a secondary product in making 
 charcoal of resinous woods ; namely of the pine and fir 
 trees. 
 
 The general process is to mark out a circular tar 
 hearth in the forest, of about 30 feet in diameter, which 
 is paved with a slope towards its centre, or at least form- 
 ed of a thick bed of well-rammed clay. From near the 
 centre a trough or covered gutter is formed, which is 
 frequently only a tree split, hollowed, and then joined 
 together with clay, with which it is also coated to defend 
 it from the fire. This trough ends in a cistern sunk in 
 the ground to receive the tar as it flows from the trough 
 
 A pole, 15 or 18 feet long, being stuck upright in the 
 centre of the hearth, the billets or fagots of resinous 
 wood are piled round it, in a bed about 20 feet in 
 diameter. Upon this, a bed of less diameter is made, 
 and so on, decreasing gradually, to form a conical pile ; 
 which is covered with fresh-cut turfs, having a few open- 
 ings round the pile, on a level with the ground. The 
 whole being left for a day or two to settle, the pole in 
 the middle is withdrawn, and the pile lighted at the hot-
 
 ORGANIC SUBSTANCES. 239 
 
 torn holes. When the pile is well-lighted, the holes are 
 stopped, and should the fire appear by any cracks in the 
 covering, fresh turfs are laid to the place. The third 
 Jay, the end of the gutter is opened next the cistern, 
 which had hitherto been stopped, and the tar already 
 made, permitted to run out. This 'opening is then closed 
 again, and only opened two or three times a day, during 
 the remainder of the process. 
 
 The tar thus obtained generally requires to be heated 
 in large iron pots, to drive away the water and pyrolig- 
 neous acid that runs out along with it, and cannot be 
 separated by ladling; and also to allow the sand, and 
 other impurities which the tar, in this rude process, has 
 acquired, to settle, and be thus separated. 
 
 GREEN TAR. 
 
 THIS is made in the same manner as common tai,- 
 from the wood of those trees which have done yielding 
 turpentine by incision. 
 
 Tar is used as a cheap vainish for wood- work; also 
 as a raw material to make pitch. 
 
 PYROLIGNEOUS TAR. 
 
 THIS is a secondary product, collected in distilling 
 wood which is not of a resinous nature, or charcoal for 
 making gunpowder. 
 
 It may be used for the same purposes as tar; with 
 which, however, it will not unite. 
 
 Since the use of coal gas for illumination, a secondary 
 product has been obtained, which has partly superseded 
 the common coal tar, which has been made in brick fur- 
 naces since the year 1740. It may be used for the same 
 purposes as common tar ; but as some prejudices exist 
 against its use, it is mostly employed for illumination. 
 
 PITCH. 
 
 Two methods are in general use for making pitch . 
 namely, either simply boiling the tar in large iron pots. 
 or setting it on fire, and letting it burn, until, by
 
 240 CHEMISTRY. 
 
 a stick .nto it, the pitch appears to have acquired a pro- 
 pei consistence. 
 
 Two barrels of the best tar, or 2| barrels of green 
 tar, are computed to make one barrel of pitch. 
 
 Pitch is used as a coarse varnish for ships' bottoms, 
 also, to close the joints of carpenters' and coopers' works 
 to enable them to retain water. 
 
 BROWN ROSIN. 
 
 THIS is the residuum left in the still after turpentine 
 has been distilled without water for its oil, and which is 
 run, or ladled out of the still into casks, cut in half foi 
 sale. 
 
 Its colour is more or less dark, sometimes approaching 
 nearly to black, according to the degree that the distil- 
 lation has been pushed. 
 
 It is used as the base of many common varnishes and 
 cements; also, to sprinkle on the surface of metals that 
 are to be joined with another metal, in order to pro- 
 mote their union. It is, also, made with tallow into a 
 soap. 
 
 When melted with a little vinegar, to render it clam- 
 my, it is us%d by violin players to rub their bows. 
 
 YELLOW ROSIN. 
 
 THIS is made by ladling out the brown rosin from the 
 stills into a vessel of hot water : a violent efflorescence 
 takes place, and the rosin absorbs one-eighth of its weight 
 of water. 
 
 It is used for the same purposes as brown rosin, but 
 is less hard, and, therefore, less adapted for cement. Ita 
 ight colour, however, is sometimes advantageous.
 
 ANIMAL SUBSTANCES. 241 
 
 ANIMAL SUBSTANCES. 
 
 AMMAL substances present us with the same constitu- 
 ent principles as vegetables: but the proportions of these 
 principles are different. By destructive distillation they 
 afford much ammonia, which is sparingly distributed in 
 the vegetable kingdom ; they also contain much nitrogen 
 of which the proportion is usually small among vegeta 
 bles; and they are most abundant in phosphorus; while 
 of carbon and hydrogen, which are abundant in vegetables, 
 they contain but little. They are also distinguished from 
 vegetables by their undergoing only the putrid fermenta- 
 tion, while vegetables, previous to this fermentation, 
 undergo one of which the product affords alcohol, and 
 another which affords vinegar. 
 
 The distinct compound substances derived from animals, 
 are very numerous ; we shall notice the most important 
 of them. 
 
 GELATINE. 
 
 GELATINE, or jelly, is supplied by all the parts of 
 animals, even bones, but is most abundant in the soft and 
 white parts. It is perfectly soluble in warm water, but 
 insoluble in alcohol, and has little taste or smell; on cool- 
 ing, when not diffused in too large a quantity cf water, 
 it has a tremulous consistence, and becomes fluid by an 
 increase of heat. Gelatine is prepared for the table 
 from calves' feet and the muscular part of animals. It 
 is a substance strongly tending to putrefaction when com- 
 bined with water, and it differs from vegetable jelly 
 chiefly in this tendency ; but if it be concentrated and 
 dried in a stove, it may be kept in a dry place for many 
 years. In this state it forms the preparation called 
 portable soup ; it is easily soluble in boiling water, and 
 u very small quantity of it forms a basin of soup. 
 
 When gelatine is obtained from the skin, cartilages, 
 and refuse of animai matter, and reduced only to the 
 consistence of a jelly, it is used in the arts under the 
 21 Q
 
 242 CHEMISTRY. 
 
 name of size. When the gelatine is concentrated and 
 dried, it forms glue. The strongest glue is afforded by 
 old animals. Isinglass is a glue which consists of the 
 air-bladder of the beluga ; a species of fash plentiful in 
 the rivers of Russia. 
 
 Gelatine is dissolved both by acids and alkalies 
 Tannin forms with it an insoluble compound. 
 
 ALBUMEN. 
 
 ALBUMEN-, or coagulable lymph, exists in its purest 
 natural state in the white of eggs, which consists almost 
 entirely of it; it is also abundant in the humours of the 
 eye, and the fluid of dropsy. Its properties are similar 
 to the albumen of vegetables. It is soluble in water, 
 before it has been coagulated by heat, but not afterwards. 
 Alkalies dissolve the coagulum. 
 
 Albumen is coagulated by acids, and in some degree 
 by alcohol. It speedily putrefies. 
 
 FIBRIN. 
 
 IF the muscle of an animal be macerated in cold 
 water, afterwards digested in alcohol, and in boiling water, 
 to remove all the parts soluble by these agents, a white, 
 insipid, fibrous substance remains, which is ca\\edjibrin. 
 
 Fibrin forms the principal part of the muscle. It is 
 insoluble in water, alcohol, ether, or oils; it has neither 
 taste nor smell ; it contracts when heated, and by a 
 stronger heat is melted. It is soluble in acids and alka- 
 lies, but not in cbld liquid ammonia. Alkalies precipitate 
 it from acids in flakes, which are soluble in hot water, 
 and resemble gelatine. With nitric acid, it aflbrds more 
 nitrogen than any other substance By destructive dis- 
 tillation, it affords water, carbonate of ammonia, a thick, 
 heavy, fetid oil, traces of acetic acid, carbonic acid, and 
 carburetted hydrogen. It also contains some phosphate 
 of soda and of lime. 
 
 Fibrin exists in blood, by which it is deposited on the 
 muscles. If the clotted or coagulated part of blood be
 
 ANIMAL SUBSTANCES. 243 
 
 tied up in a linen cloth, and washed in water till the 
 water ceases to receive either colour or taste from it 
 fibrin will remain in the linen. 
 
 Fibrin has a verv near resemblance to gluten. 
 
 B'ONES. 
 
 BONES derive solidity from the phosphate of lime 
 which forms a considerable part of them; cartilages 
 which are bones in the first part of their formation, have 
 the properties only of coagulated albumen. The gelatine 
 and fat combined with bones, impart toughness and 
 strength, and hence, when their quantity is diminished by 
 age, the bones are easily broken. One hundred parts of 
 ox-bones, according to the analysis of Fourcroy and 
 Vanquelin, are composed of solid gelatine 51, phosphate 
 of lime 37.7, carbonate of lime 10, phosphate of mag- 
 nesia 1.3. 
 
 The enamel of human teeth contains a greater quan- 
 tity of the phosphate of lime, and is destitute of gelatine. 
 The shells of animals are a species of bones ; they con- 
 tain about the same quantity of carbonate of lime, that 
 the bones of perfect animals contain of phosphate of 
 lime. 
 
 HORN. 
 
 HORNS, hoofs, nails, and quills, differ but little in their 
 chemical characters; they are found to consist chiefly 
 of condensed albumen, with some oil, and a very small 
 proportion of gelatine and phosphate of lime. 
 
 Stag's horn and ivory are nearly the same as bone, 
 and contain much gelatine. 
 
 Hair, wool, and feathers, differ but little from each 
 other in their composition ; one fourth of their weight 
 consists of oil, on which their colour depends ; they afford 
 besides, water, ammonia, carbon, silex, and iron. Hair 
 is soluble in alkalies, with which it forms soap. 
 
 BLOOD. 
 
 BLOOD, recently drawn from an animal, appears to be 
 a thin and homogeneous flu ; d ; but it soon separates into
 
 244 CHEMISTRY. 
 
 two parts, the one a coagulated part, called the crast>a- 
 mentum ; the other a fluid, called the serum. 
 
 The crassamentum is of a red colour ; it contains albu- 
 men, iron, soda, and fibrin ; the fibrin constitutes its basis, 
 and may be obtained separately by washing it in water. 
 It has all the properties of the fibrin obtained from muS' 
 cular fibre. The crassamentum has a specific gravity 
 if 1.245, whereas, that of blood is only about 1.05. 
 
 Serum is of a light greenish colour. Its taste is 
 slightly saline, and it turns syrup of violets green ; this 
 oroperty it owes to the uncombined soda which it con- 
 rains. It is coagulable by a temperature of 156, and is 
 v .hen of a greyish white colour ; it, therefore, contains a 
 'arge proportion of albumen; it also contains gelatine, 
 nydrosulphuret of ammonia, soda, muriate of soda, phos- 
 phate of soda, and phosphate of lime. Acids perma- 
 nently coagulate serum ; alkalies increase its fluidity ; 
 ilcohol coagulates it, but the coagulum is soluble in 
 water. 
 
 When the blood, after circulating through the body, 
 has arrived at the lungs in its way to the heart, it has 
 acquired a dark colour ; but when, in the lungs, it has 
 been exposed to atmospheric air, it absorbs oxygen, with 
 3. minute portion of nitrogen, and parts with carbon ; 
 the consequence of this operation is its acquiring an 
 increase of heat, and a fine crimson colour. 
 
 MILK. 
 
 MILK is usually considered as consisting of three parts , 
 the caseous, butyraceous, and serous, which, upon its 
 being allowed to stand in an open vessel, spontaneously 
 separate from each other. 
 
 The butyraceous part, or cream, rises to the surface, 
 and, when designed to furnish butter, it is skimmed off 
 and, being put into a vessel in which it can be rapidly 
 agitated, the butter separates from it. Butter, when 
 fluid, is transparent; but it becomes opaque, as it cools 
 and hardens. The butter of cows' milk becomes hardei 
 !han that of any other animal.
 
 ANIMAL SUBSTANCES 245 
 
 The caseous, or cheesy part of milk is obtained by co 
 agulating milk with an acid. For this purpose, in pre- 
 paring cheese from cows' milk, rennet is used which is 
 the stomach of a calf in which milk has soured. The 
 f-oagulum is separated from the fluid part, to make 
 cheese. 
 
 After the whole of the matter which is capable of co- 
 agulating is separated from milk, the serous, or watery 
 part only remains : but rennet, from its slight acidity, 
 does not make a complete separation. The fluid, there- 
 fore, remaining after rennet has been used, still contains 
 saccharine particles and curd, and, under the name of 
 whey, is used as a wholesome beverage. The serum ob- 
 tained by the spontaneous decomposition of milk is acidu- 
 lous, and totally devoid of nourishment. 
 
 If sweet whey be evaporated to the consistence of 
 honey, and afterwards dried in the sun, a solid substance 
 is obtained, which is called sugar of milk. If the sugar 
 of milk thus prepared be dissolved in water, it may be 
 clarilied by whites of eggs, and will afford white crystals, 
 after being evaporated to the consistence of a syrup. 
 Sugar of milk is soluble in three or four parts of water: 
 its taste is slightly sweet; and it yields, by distillation, 
 nearly the same products as other sugar. 
 
 Milk is capable of undergoing the vinous fermentation, 
 and, consequently, of affording a spiritous liquor. Marco 
 Polo, who wrote in the thirteenth century, asserted, that 
 liquor prepared from mares' milk, by the Tartars, 
 might be taken for white wine. If milk be deprived 
 of its cream, it will not afford a spiritous fluid. 
 
 Thenard gives the following as the component parts 
 of milk; 1, water; 2, acetous acid ; 3, caseous; 4, buty- 
 raceous ; 5, saccharine ; and 6, by extractive matter ; 
 7, 8, muriate of soda, and potass; 9, sulphate of potass; 
 10, 11, phosphates of lime and magnesia. The acid here 
 called the acetous, is now found to have different pro- 
 perties, and is called the lactic acid. (See Lactic acid.) 
 The milk of different animals in its composition asses' 
 mares' and '^omens' milk are the most saline and 
 21 *
 
 246 CHEMISTRY. 
 
 serous ; cows', goats', and sheep's, contain the most of the 
 caseous and butyraceous parts. 
 
 CARTILAGE. 
 
 A WHITE, elastic, glistening substance, growing to the 
 bones, and commonly called gristle. Cartilages are di- 
 vided, by anatomists, into abducent, which cover the 
 moveable articulationsof bones; and in terarticular, which 
 are situated between the articulations and uniting car 
 tilages, which unite one bone with another. Their use 
 is, to facilitate the motions of bones, or to connect them 
 together. 
 
 The chemical analysis of cartilage affords one-third 
 the weight of the bones, when the calcareous salts are 
 removed by digestion in dilute muriatic acid. It resem- 
 bles coagulated albumen. Nitric acid converts it into 
 gelatine. With alkalies, it forms an animal soap. Carti 
 lage is the primitive paste into which the calcareous sails 
 are deposited in the young animal. In the disease, rick- 
 ets, the early matter is withdrawn by morbid absorption, 
 and the bones return into the state nearly of flexible 
 cartilage. Hence arise the distortions characteristic of 
 this disease. 
 
 ANIMAL GLUTEN. 
 
 THIS substance constitutes the basis of the fibres of 
 all solid parts. It resembles in its properties, the gluteu 
 of vegetables. 
 
 GLUE. 
 
 Air inspissated jelly, made from the parings of hides, 
 and other offals, by boiling them in water, straining 
 through a wicker basket, suffering the impurities to sub- 
 side, and then boiling it a second time. The articles 
 should first be digested in lime-water, to cleanse them 
 from grease and dirt, then steeped in water, stirring them 
 well from time to time ; and, lastly, laid in a heap to 
 have the water pressed out, before they are put into the 
 boiler. Some recommend that the water should be kept
 
 BITUMINOUS SUBSTANCES. 247 
 
 as nearly as possible to a boiling heat, without suffering 
 it to enter into ebullition. In this state, it is poured into 
 flat frames or moulds, then cut into square pieces when 
 congealed, and, afterwards, dried in a coarse net It is 
 said to improve by age ; and that glue is reckoned the 
 best, which swells considerably, without dissolving, by 
 three or four days' infusion in cold water, and recovers 
 its former dimensions and properties by drying. Shreds, 
 or parings of vellum, parchment, or white leather, make 
 a clear, and almost colourless glue. (See Mechanica 
 Exercises.) 
 
 BITUMINOUS SUBSTANCES. 
 
 ASPHALTUM. 
 
 ASPHALTUM is a smooth, hard, brittle, black or brown 
 su.'jstance, which breaks with a polish, melts easily when 
 heated, and when pure burns without leaving any ashes. 
 It is found in a soft or liquid state on the surface of the 
 Dead Sea, but by age grows dry and hard. The same 
 kind of bitumen is likewise found in the earth in other 
 parts of the world ; in China, America, particularly in 
 the Island of Trinidad ; and in some parts of Europe, as 
 the Carpathian hills, France, Neufchatel, &c. 
 
 According to Neumann, the asphaltum of the shops is 
 a very different compound from the native bitumen; and 
 varies, of course, in its properties, according to the nature 
 of the ingredients made use of in forming it. On this 
 account, and probably from other reasons, the use of 
 asphaltum, as an article of the materia medica, is totally 
 laid aside. 
 
 The Egyptians used asphaltum in embalming, under 
 the name of mumia mineralis, for which it is well 
 adapted. It was used for mortar at Babylon. 
 
 BITUMENS. 
 
 THIS term includes a considerable range of inflam- 
 mable mineral substances, burning with flame in *he open
 
 248 CHEMISTRY. 
 
 air. They are of different consistency, from a thin fluio 
 to a solid ; but the solids are for the most part liquefiable 
 at a moderate heat. The fluid are, 
 
 1. Naphtha, a fine, white, thin, fragrant, colourless oil 
 which issues out of white, yellow, or black clays in 
 Persia and Media. This is highly inflammable, and is 
 decomposed by. distillation. It dissolves resins, and the 
 essential oils of thyme and lavender ; but is not itself 
 soluble either in alcohol or ether. It is the lightest of 
 all the dense fluids, its specific gravity being 0.708. 
 
 2. Petroleum, which is from a yellow, reddish, brown s 
 greenish, or blackish oil, found dropping from rocks, or 
 issuing from the earth, in the duchy of Modena, and iu 
 various other parts of Europe, and Asia. This, like- 
 wise, is insoluble, in alcohol, and seems to consist of 
 naphtha, thickened by exposure to the atmosphere. It 
 contains a portion of the succinic acid. 
 
 3. Larbadoes tar, which is a viscid, brown, or black 
 inflammable substance, insoluble in alcohol, and contain- 
 ing the succinic acid. This appears to be the mineral 
 oil in its third state of alteration. 
 
 The solid are, 1. Asphaltum, mineral pitch, of which 
 there are three varieties : the cohesive ; the semi-com- 
 pact, maltha; the compact, or asphaitum. These are 
 smooth, more or less hard or brittle, inflammable sub- 
 stances, which melt easily, and burn without leaving any 
 or but little ashes if they be pure. They are slightly 
 and partially acted on by alcohol and ether. (See 
 Asphaltum.) 
 
 2. Mineral tallow, which is a white substance of the 
 consistence of tallow, and as greasy, although mon. 
 brittle. It was found in the sea on the coast of Finlano 
 n the year 1736; and is also met with in some rock) 
 parts of Persia. It is near one-fifth lighter than tallow 
 burns with a blue flame and a smell of grease, leaving a 
 black viscid matter behind, which is more difficultly 
 consumed. 
 
 3. Elastic bitumen, or mineral caoutchouc, of which 
 there are two varieties. Besides these, there are other
 
 BITUMINOUS SUBSTANCES. 249 
 
 bituminous substances, as jet and amber, which approach 
 the harder bitumens in their nature; and all the varieties 
 of pit-coal, and the bituminous schistres, or shale, which 
 contain more or less of bitumen in their composition. 
 
 AMBER. 
 
 A BEAUTIFUL bituminous substance, which takes a good 
 polish, and after a slight rubbing, becomes so electric, as 
 fro attract straws and small bodies. Amber is a hard, 
 brittle, tasteless substance, sometimes perfectly transpa- 
 rent, but mostly semi-transparent or opaque, and of a 
 glossy surface ; it is found of all colours, but chiefly 
 yellow or orange, and often contains leaves or insects 
 its specific gravity is from 1.065 to 1.100; its fracture i 
 even, smooth, and glossy ; it is capable of a fine polish 
 and becomes electric by friction ; when rubbed or heated, 
 it gives a peculiar agreeable smell, particularly when it 
 melts, that is at 550 of Fahrenheit, but then it loses its 
 transparency; projected on burning coals, it burns with 
 a whitish flame, and a whitish yellow smoke, but gives 
 very little soot and leaves brownish ashes ; it is insoluble 
 in water and alcohol, though the latter, when highly 
 rectified, extracts a reddish colour from it; but is soluble 
 in the sulphuric acid, which then acquires a reddish 
 purple colour, and is precipitable from it by water. No 
 other acid dissolves it, nor is it soluble in essential or 
 expressed oils, without some decomposition and long di- 
 gestion ; but pure alkali dissolves it. By distillation it 
 affords a small quantity of water, with a little acetous 
 acid, an oil, and a peculiar acid. 
 
 Amber is met with plentifully in regular mines in some 
 parts of Prussia. The upper surface is composed of 
 sand, under which is a stratum of loam, and under this 
 a bed of wood, partly entire, but chiefly mouldered or 
 changed into a bituminous substance. Under the wood 
 is a stratum of sulphuric or rather aluminous mineral 
 in which the amber is found. Strong sulphuric exhala 
 tfons are often perceived in the pits. Detached pie** * 
 are also found occasionally on the sea coast in varie *
 
 250 CHEMISTRY. 
 
 countries. It has been found in gravel beds near London 
 In the Royal Cabinet at Berlin there is a mass of ISlbs- 
 weight, supposed to be the largest ever found. Jussieu 
 asserts, that the delicate insects in amber, which prov 
 the tranquillity of ij;s formation, are not European. 
 Hany has pointed out the following distinction between 
 mellite and copal, the bodies which most closely resem- 
 ble amber. Mellite is infusible by heat. A bit of copal 
 heated at the end of a knife takes fire, melting into 
 drops, which flatten as they fall; whereas amber burns 
 with spitting and frothing ; and when its liquified parti- 
 cles drop, they rebound from the plane which receives 
 them. The origin of amber is at present involved in 
 perfect obscurity, though the rapid progress of vegetable 
 chemistry promises soon to throw light on it. Various 
 frauds are practised with this substance. Neumann 
 states as the common practice of workmen, the two 
 following: The one consists in surrounding the amber 
 with sand in an iron pot, and cementing it with a gradual 
 fire for forty hours, some small pieces placed near the 
 sides of the vessel being occasionally taken out for judging 
 of the effect of the operation : the second method, which 
 he says is that most generally practised, is by digesting 
 and boiling the amber about twenty hours with rapeseed 
 oil, by which it is rendered both clear and hard. 
 
 Werner has divided it into two sub-species, the white 
 and the yellow ; but there is little advantage in the dis- 
 tinction. Its ultimate constituents are the same with 
 those of vegetable bodies in general ; viz. carbon, hydro- 
 gen, and oxygen. 
 
 In the second volume of the Edinburgh Philosophical 
 Journal, Dr. Brewster has given an account of some 
 optical properties of amber, from which he considers it 
 established beyond a doubt, that amber is an indurated 
 vegetable juice ; and that the traces of a regular struc- 
 ture, indicated by its action upon polarized light, are 
 not the effect of the ordinary laws of crystallization by 
 which mellite has been formed, but are produced by tlft; 
 same causes which influence the mechanical condition of
 
 OF CRYSTALLIZATION. 251 
 
 gam-arabic, and other gums, which are known to be 
 formed by the successive deposition and induration of 
 vegetable fluids. 
 
 OF CRYSTALLIZATION. 
 
 CRYSTALS are aggregations of the particles of bodies, 
 which have been spontaneously disposed in a regular 
 form ; and crystallization denotes the act of their forma- 
 tion. According to the strict meaning of the word, a 
 crystal should be transparent, as well as symmetrical in 
 its form ; but it is now extended to opaque substances, and 
 regularity of form is its leading characteristic. 
 
 Crystallization is of two kinds, the dry and the humid ; 
 dry crystallization refers to metals and other substances 
 which cannot combine wiih water; the humid crystalliza- 
 tion refers to fluids and gases holding solids in solution ; 
 and which never affords crystals but what contain more 
 or less water. 
 
 The water combined with a crystal is called its water 
 of crystalli7.ation. No crystals are transparent unless 
 they contain water. The water, in thus combining with 
 bodies, loses its caloric of fluidity. 
 
 The same substance, under the same circumstances, 
 always affords crystals of the same figure ; but except- 
 ing the circumstances which modify the natural process 
 of crystallization, all the differences observed in the forms 
 of crystals, are attributable to differences in the forms 
 of the integral particles of the crystals. 
 
 Crystallization cannot take place unless the particles 
 of bodies be at liberty to arrange themselves according to 
 their peculiar attractions. Hence it is necessary, either 
 that they be in a state of solution, or suspended in a 
 fluid, in a state of extremely minute division, or in fusion. 
 It has not been decisively proved that mere suspension 
 will produce such a regular arrangement of particles as 
 can be called crystallization ; but admitting this to. be
 
 252 CHEMISTRY. 
 
 possible, the division of the particles which form the 
 crystab must be carried so far as scarcely to differ from 
 solution, and the same explanation will apply as to solu 
 tion. 
 
 Suppose we have a saturated solution of common salt 
 in water ; the particles of the salt are so completely dis- 
 persed through the water, and probably so far removed 
 from each other, that the particles of the water exert a 
 stronger attraction on them than they exert on each 
 other : the solution, therefore, remains perfect ; but let 
 some of the water be evaporated ; it is now evident that 
 as the same quantity of salt is contained in a less compass, 
 the particles of the salt must have approximated each 
 other, and are within the sphere of each other's attrac- 
 tion : they, therefore, aggregate and form crystals, until 
 the solution is of the same intensity as at first. If the 
 evaporation be resumed, more crystals are formed in the 
 same manner, until at last, by the evaporation of the 
 whole of the water, the crystals are obtained dry. 
 
 The crystallization of a metal is not essentially differ- 
 ent fnom an aqueous crystallization. The metal may be 
 regarded as held in solution by caloric ; and, as the ca- 
 loric of fluidity is withdrawn by the cooling of the metal, 
 the case is correspondent to that of the reduction of the 
 quantity of water in the aqueous solution, and the parti- 
 cles will arrange themselves according to their form. 
 It must be obvious, that if the particles of the metal, 
 or of % the solid in solution, consist of cubes, they will ag- 
 gregate in forms of one description ; and, if they art 
 tetrahedrons, they must place themselves upon each 
 other in another. 
 
 A fluid which has furnished all, or the greater part ot 
 the crystals that can be obtained from it, is called mother 
 water. 
 
 In general, fluids at a boiling-heat hold in solution a 
 much larger portion of any matter than when cold, be- 
 cause caloric has a powerful effect in lessening the 
 attraction of aggregation, and preventing particles which 
 are 4^ery near from combining. Common salt is, how
 
 CRYSTALLIZATION. 2i>3 
 
 wer, an instance of a common salt which is nearly, as 
 soluble in cold, as in hot water : but it appears to be a 
 general law, that salts of this kind require but a small 
 quantity of the water of crystallization. 
 
 Salts which,acquire moisture from the atmosphere, so 
 as to hecome fluid or pulpy, are said to be deliquescent : 
 when they lose their crystalline form in the air, and yet 
 remain dry and powdery, it is because their water of 
 crystallization has been abstracted ; and they are said to 
 be efflorescent. 
 
 A salt is deliquescent, when it has a greater attrac- 
 tion for water than the air; as it will, inlhat case, take 
 water from the air: a salt is efflorescent, when it has 
 a less attraction for water than the air ; for the air will 
 then abstract water from it. When the salt has the 
 same attraction for water with the air, it will suffer no 
 change. 
 
 The slower the crystallization, the larger, the harder, 
 the more regular and transparent, the crystals which 
 are formed. A rapid evaporation of a solution, there- 
 fore, produces imperfect crystals, the particles not having 
 time to assume the exact arrangement to which they are 
 naturally disposed. 
 
 Crystallization is promoted when the solution is fur- 
 nished with some point at which it may commence. 
 
 In a saturated solution which exhibits no signs of crys- 
 tallization, crystals will soon be observed, if a thread be 
 stretched through it. But if, instead of any foreign mat- 
 ter, a crystal of substance in solution be introduced, the 
 crystallization is still further promoted. Upon this fact 
 Le Blanc founded a method of obtaining very large and 
 perfect crystals. He selected the largest and most per- 
 fect crystals of salt recently formed, and put them into a 
 saturated solution of the same salt. As the side of a 
 crystal in contact with the vessel receives no increase, 
 they were turned daily. After a certain time, the largest 
 and most reg - :lar crystals thus obtained were employed 
 as the nucleus ;>f still larger crystals, by a repetition of 
 the process. 
 22
 
 254 CHEMISTRY. 
 
 JECirwan observed, that if two salts be held in solution 
 by the same fluid, a crystal of either will causa that %alt 
 to crystallize which is of the same kind as itself. 
 
 Crystallization goes on but very slowly in closed ves 
 eels; and, in most instances, wholly stops: but Dr. Hig- 
 gins inferred, from his experiments, that the atmosphere 
 only facilitates the process in consequence of its pressure; 
 and, therefore, a sufficient column of mercury, or any 
 ther pressure, has the same effect. Perhaps the ex- 
 periment has not been tried in a proper manner : the 
 pressure upon the surface of a fluid, in a closed vessel 
 containing air, is not less than when that vessel is un- 
 covered. 
 
 The action of light has the effect of impeding and dis- 
 turbing crystallization : and crystals are, therefore, 
 larger, and more regular, when formed in the dark. 
 
 A very singular discovery was accidentally made by 
 Hany, respecting the elementary forms of crystals. 
 Happening to take up a hexangular prism of calcareous 
 spar, which had been detached from a group of the 
 same kind, he observed that a part of the crystal was 
 wanting, and yet that it presented a smooth surface. 
 Attempting to detach a segment from the contiguous 
 edge, he could not succeed ; but the ore next it was 
 easily divided. Proceeding thus to divide the crvstals 
 mechanically, in such a way that the separation was 
 easy, and left smooth surfaces, and which did not hap- 
 pen unless in directions parallel to the first fracture, he 
 found that the crystal changed its form as parts of it 
 were separated, until at length it acquired a form that 
 remained mathematically the same after any subsequent 
 sections. On trying the experiment, he found that other 
 crystals of the same spar were reducible to the same 
 unalterable form ; and that crystals of other bodies 
 were also reducible to fixed forms, of one kind or an- 
 other. These fixed forms, therefore, he denominates 
 the primitive forms of the crystals; and the other 
 forms which crystals assume, he calls their secondary 
 foms.
 
 COMBUSTION. 255 
 
 The primitive form of a fluate of iron, Hany found 
 f> be an octahedron ; of sulphate of barytes, a prism, 
 with rhomboidal bases ; of corundam, a rhomboid, 
 somewhat acute ; of beryl, an hexahedral prism ; of 
 olend, a dodecahedron, with rhomboidal sides. 
 
 Pursuing the path which these discoveries pointed out, 
 with -a rare combination of industry and ingenuity, he 
 succeeded in delineating a system of crystalography, 
 which, though yet in its infancy, bears the strongest indi- 
 cations of remaining consistent with the phenomena of 
 nature, and, therefore, of obtaining a permanent recep- 
 tion in science. 
 
 OF COMBUSTION. 
 
 COMBUSTION is the union of a body with oxygen accom- 
 panied by the evolution of light and heat; and, there- 
 fore, every body which is capable of forming this union, 
 is called a combustible. 
 
 Oxvgen is retained in the gaseous state by the large 
 quantity of caloric with which it is combined, and for 
 which it has a strong attraction ; but if any substance 
 be presented to the oxygen gas, that has a stronger 
 attraction for oxygen than oxygen has for caloric, the 
 consequence is, that the oxygen gas is decomposed, its 
 particles unite with the substance thus presented to it, 
 and a great part of the caloric being then left in an 
 uncom bined state, recovers the properties which are 
 peculiar to it in that state, that is, it assumes the appear- 
 ance of tire. The heat thus produced is the more 
 intense, the greater the quantity of caloric which is 
 liberated in a given compass and time ; and these cir- 
 cumstances are dependent upon the strength of the 
 affinity between oxygen and the substance which sepa- 
 rates it from caloric, and the quantity of caloric required 
 to saturate the product of combustion. 
 
 At the ordinary temperature of the atmosphere, bodies 
 
 Have either no affinity for oxygen, or usually a very wenk 
 
 ne hence they suffer no change, or the change vvMch
 
 256 CHEMISTRY. 
 
 does take place is so slow, that though a combustion in 
 effect, it is not called by that name, because neither light 
 nor heat are perceptible to the senses. 
 
 When the temperature of a combustible is raised, its 
 affinity for oxygen is increased ; and when it is raised to 
 a certain point, which varies according to the nature of 
 the substance, the affinity becomes very strong, the com- 
 bustion is consequently rapid and brilliant, taking, accord- 
 ing to the phenomena it presents, the name of ignition 
 inflammation, decrepitation, detonation, or fulmination. 
 
 Light appears to form a component part of all com- 
 bustible bodies, and to enter, as well as caloric, into the 
 composition of oxygen itself. Hence, when oxygen by 
 combustion enters into a new combination, part at least 
 >f the light held both by it and the combustible, is dis- 
 engaged and flies off, as well as the caloric. In general 
 t appears evident, that the light is furnished by the com- 
 bustible, because the light furnished by different com 
 bustibles is of different colours, and the quantity of it is 
 by no means proportionate to the quantity of oxygen 
 consumed. For example, hydrogen in combustion com- 
 bines with a greater quantity of oxygen than any other 
 body ; but the light afforded is inconsiderable. 
 
 Although the light furnished by combustion is not pro- 
 portionable to the quantity of oxygen which enters into 
 combination, and therefore is evidently not wholly fur- 
 nished by the oxygen, yet the case is the reverse with 
 the caloric evolved. The combustion of those bodies 
 which combine with the greatest quantity of oxygen, 
 always furnishes the greatest quantity of caloric, and 
 therefore the combustion of hydrogen furnishes the most 
 intense heat that can be produced, until some other sub- 
 stance shall be found which combines with a greater 
 quantity of oxygen. 
 
 Another proof that the chief part of the caloric ex- 
 tricated during combustion is furnished by the oxygen, 
 which when it ceases to be a gas, has no longer occasion 
 for it, is, that when the oxygen is in combination with a 
 fluid, a combustible substance, for example, a metal, wilJ
 
 OF COMBUSTION. 257 
 
 nostract it from the fluid, but the usual phenomena of 
 combustion do not appear, although the combination with 
 oxygen is so rapid, that if the same quantity of oxygen 
 had been derived from a gas, in the same time, these 
 phenomena would have been exhibited with considerable 
 splendour. 
 
 Bodies which have been once thoroughly burnt, which 
 is only another way of expressing that they are saturated 
 with oxygen, are incapable of undergoing combustion 
 again, until some part or all of their oxygen is abstracted. 
 To deprive them of their oxygen is virtually to unburn 
 them ; and when no part of a combustible has been dis- 
 sipated, but only changed by the new combination, the 
 abstraction of the oxygen absorbed restores its pristine 
 properties. This is the case with metals, which acquire 
 by combustion a weight equal to the oxygen combined 
 with them, and of course lose that acquired part of their 
 weight when the oxygen, which constitutes it is with- 
 drawn ; but vegetables and other combustible matters 
 containing many volatile parts, when burnt in the open 
 air, have these parts dissipated, and therefore the pro- 
 ducts they afford after combustion, weigh considerably 
 less than the vegetables themselves, as they only consist 
 of those parts which cannot be converted into gas. 
 
 We have stated that many substances, by their union 
 with oxygen in combustion, are converted into acids ; 
 when this happens, the combustible is said to be oxygen- 
 ized ; when the product of combustion is not an acid, it 
 is called an oxide, and the combustible is said to be 
 oxidized. 
 
 The experiments which have proved the alkalies and 
 earths to be metallic oxides, have tended materially to 
 establish the conclusion, that all substances are either 
 combustible, or combined with oxygen to the point of 
 aturation ; and if this be maintained, oxygen must, like 
 caloric, have an affinity for every substance existing. 
 22* R
 
 ELECTRICITY. 
 
 A PROPERTY which certain bodies possess when rubbed 
 fteated, or otherwise excited, whereby they attract re- 
 mote bodies, and frequently emit sparks, or streams of 
 light. 
 
 Abstract of Electricity. 
 
 1. Electricity is supposed to be a fluid, which repel 
 its own particles, but attracts all other matter. 
 
 2. That portion of electricity which every body is sup- 
 posed to contain, is called its natural share. 
 
 3. When a body is possessed of either more or less than 
 its natural share, it is said to be electrified or charged. 
 
 4. If it possesses more than its natural share, it is said 
 to be positively electrified : if it contains less than its 
 natural share, it is said to be negatively electrified. 
 
 5. Bodies through which the electric fluid passes free- 
 ly, are called conductors, or non-electrics. Those bodies 
 which oppose the passage of electricity, are called non- 
 conductors, or electrics. 
 
 6. Glass, and some other bodies, which are non-con- 
 ductors at common temperature, become conductors, 
 when very hot. 
 
 7. The equilibrium of the electric fluid is disturbed by 
 the friction of bodies against each other; and electricity 
 is then said to be produced, or excited. 
 
 8. Electricity is excited in the greatest quantity by 
 the friction of conductors and non-conductors against 
 each other. 
 
 9. The same substance, excited by a different rubbci, 
 will alternately be electrified positively and negatively. 
 
 10. Two bodies, both positively, or both negatively 
 electrified, repel each other; whereas, if one body be 
 positive, and the other negative, they will attract each 
 other. 
 
 11. Upon this principle are constructed electrometers, 
 or instruments for ascertaining whether bodies are elec- 
 trified or not.
 
 ELECTRICITY. 259 
 
 12. If a body, containing only its natural share of 
 Electricity, be presented sufficiently near to a body elec- 
 trified positively or negatively, a quantity of electricity 
 will force itself through the air, from the latter to th<2 
 former, appearing in the form of a spark. 
 
 13. When two bodies approach each other sufficiently 
 near, one of which is electrified positively, and the other 
 negatively, the superabundant electricity rushes vio- 
 lently from one to the other, to restore the equilibrium 
 between them. This effect also takes place, if the two 
 bodies be connected by a conducting substance. 
 
 14. If an animal be placed so as to form part of this 
 circuit, the electricity, in passing through it, produces 
 a sudden effect upon it, which is called the electric 
 shock. 
 
 15. The motion of electricity, in passing from a posi- 
 tive to a negative body, is so rapid, that it appears to be 
 instantaneous. 
 
 16. When any part of a piece of glass or other elec- 
 tric is presented to a body electrified positively or nega- 
 tively, that part becomes possessed of the contrary elec- 
 tricity to the side of the body it is presented to ; and the 
 other side of the glass is possessed of the same kind of 
 electricity as the other body. 
 
 17. The electricity communicated to glass and other 
 perfect electrics, does not spread, but is confined to the 
 part where it is communicated, on account of the non- 
 
 conducting qualitv of the glass. 
 18. To effe 
 
 18. To effect the communication, and to enable it to 
 be applied to the whole surface, the glass is covered on 
 both sides with tin-foil, or some other conductor, in which 
 case the glass is said to be coated. 
 
 19. If a communication by means of a conductor, be 
 made between the two sides of a glass thus coated and 
 charged with electricity, a discharge takes place, by 
 which the two sides recover their natural state. 
 
 20. The coated glass may either be flat or any other 
 form ; but cylindrical jars are found to be the most con- 
 venient form. The Leyden phial is nothing more than 
 a glass of this description.
 
 260 ELECTRICITY. 
 
 21. When several jars or phials are connected together 
 so as to be charged and discharged simultaneously, they 
 constitute an electrical battery. % 
 
 22. Electricity is capable of producing the most power- 
 ful effects, melting the metals, and firing all the inflam- 
 mable substances. A strong shock sent through metallic 
 oxides, frequently reduces them to a metallic state. 
 
 23. The machines by which electricity is artificially 
 accumulated, for the purpose of charging jars or bat- 
 teries, are constructed with either a cylinder or plate of 
 glass, which is whirled round in contact with a body 
 called a rubber, and the electricity is taken ofif as it is 
 produced, by a non-electric called the prime conductor. 
 
 24. Cylinder machines are the most easily constructed ; 
 but plate machines are the most compact and elegant. 
 
 25. Several bodies become transparent during the pas- 
 sage of electricity through them ; a circumstance which 
 has given rise to the conjecture that electricity may be 
 the cause of all transparency. 
 
 26. Metallic points attract the electricity from bodies, 
 and discharge them silently. This property has ren- 
 dered them useful in defending from lightning. 
 
 27. When electricity enters a point, it appears in the 
 form of a star ; when it issues from a point, it puts on 
 the appearance of a brush or pencil. 
 
 28. Machines may be put in motion by the electric 
 fluid which issues from a point. 
 
 29. The shock of an electric battery will communicate 
 magnetism to steel bars lying in or near the magnetic 
 meridian ; and a magnetic bar may have its poles re- 
 versed, or its magnetic properties destroyed, by impart 
 ing the shock while it is in different positions. 
 
 30. Electricity is evolved in heating and cooling of 
 various bodies ; also in the evaporation and condensation 
 cf vapours. 
 
 31. Vapour requires, for its natural share, a greater 
 quantity of electricity than water, from which it was 
 produced. 
 
 32. When quantity of vapour is, in any degree, con-
 
 GALVANISM. 261 
 
 densed, it has, therefore, electricity to give out ; that is, 
 in the positive state. When a quantity of vapour is fur 
 iher expanded, it requires, for its natural share, more 
 electricity than before ; that is, in the negative state. 
 
 33. By the ascent of vapour, immense quantities of 
 electricity are carried from its reservoir, the earth ; and, 
 by the unceasing alternations of rarefaction and conden- 
 sation, the atmosphere is always more or less in an elec- 
 trical state. 
 
 34. Lightning is a vast accumulation of electricity. 
 
 35. Thunder is the noise produced by the solid parti- 
 cles of air rushing together, after having been separated 
 by lightning ; the rapidity of the motion of which is such 
 as to produce a vacuum as it proceeds. 
 
 36. In the eruptions from volcanoes, lightning is almost 
 always present ; and earthquakes are generally accom- 
 panied by a disordered state of the atmosphere ; often 
 with great thunder-storms. Hence, electricity is sup- 
 posed to be intimately connected with these phenomena. 
 
 37. In the healing art, electricity appears capable of 
 producing, in manv cases, the most excellent effects. In 
 applying it, the general rule is to begin gently, and to 
 continue the application, at periodical intervals, for a 
 considerable time. 
 
 GALVANISM. 
 
 GALVAMSM is a species of electricity which is produced 
 by a peculiar action of metallic and other electrical con- 
 ductors on each other. 
 
 Abstract of Galvanism. 
 
 1. Galvanism appears only to be a method of exciting 
 electricity. The first efficient observation,of its effects 
 originated with Galvani, from whom it derives its name ; 
 but it was Volta who firet' rendered it interesting, by dis- 
 covering the method of accumulating it. 
 
 2. Ga'vanic electricity is produced by the chemi* \\
 
 2G2 MAGNETISM. 
 
 action of bodies upon each other; particularly by the 
 oxidation of metals, during which process, considerable 
 quantities are evolved. 
 
 3. It appears to be in a state of less intensity or con- 
 densation than the electricity obtained by the electrical 
 machine. 
 
 4. It will oxidize metals, and set fire to all inflammable 
 substances: it will also give a charge to a Leyden phial. 
 
 5. Of all known substances, the nerves of animals, re- 
 cently dead, appear to be the most easily affected by it 
 and constitute electrometers of exquisite delicacy. 
 
 6. It is conducted, and refused a passage by some 
 substances, as common electricity. 
 
 7. When a living animal forms a part of its circuit, it 
 produces a sensation resembling that of the electric 
 shock. 
 
 8. Electricity is generated by the galvanic battery ; 
 but only collected or transferred by the electrical ma- 
 chine ; and, therefore, the effects of the former are in- 
 creased by insulation. 
 
 9. The power of galvanism in consuming wires, is 
 greatest when the plates are numerous : but in giving a 
 shock, it is greatest when the plates are large, the quan- 
 tity of surface in each case being the same. 
 
 MAGNETISM. 
 
 A PECULIAR species of attraction, excited by bodies 
 called magnets or loadstones, receives the appellation of 
 magnetism. 
 
 Abstract of Magnetism. 
 
 1. THAT principle which produces the phenomena of 
 magnetism, K not cognizable by our senses, except by 
 its effects ; tfut it is considered to be a fluid, and spoken 
 of under the denomination of the magnetic fluid. 
 
 2. Iron has been usually cdfcsidered as the only sub- 
 stance susceptible of magnetism ; but late investigations,
 
 MAGNETISM. 263 
 
 which have been made with great care, have rendered 
 it extremely probable that both nickel and cobalt like- 
 wise submit to the influence of the same power. 
 
 3. Magnets are either natural or artificial ; natural 
 magnets are ores of iron, dug out of the earth in a mag 
 netical state ; artificial magnets are made of steel, by 
 the help of a natural magnet. 
 
 4. In every magnet there are two opposite points, 
 which at all times and places, will, if the magnet be at 
 liberty to move either without or with very little friction, 
 turn to the poles of the world, or nearly so. 
 
 5. It is this singular property, which is called polarity, 
 that renders the magnet so useful in navigation. 
 
 6. The poles of magnets, if of the same name, as 
 when two north or two south poles are brought near 
 together, repel each other; different poles, on the con- 
 trary, attract each other. The centre of a magnet 
 neither attracts nor repels. 
 
 7. The earth itself acts as a great magnet, the poles 
 of which nearly but not quite coincide with the geo- 
 graphical poles. 
 
 8. It is this difference between the magnetical and the 
 geographical poles, that produces the declination of the 
 needle, which turns to the former, and only indicates the 
 latter by the nearness of the two. 
 
 9. The magnetical poles are not fixed points, but the 
 cause of their motion is unknown. 
 
 10. The constant change which the motion of the 
 magnetic poles produces in the declination of the needle, 
 s the cause of what is called the variation of the com- 
 pass. 
 
 11. At all places not 90 degrees from the magnetic 
 poles, one pole of a magnet suspended by its centre sinks 
 below the horizon, which is called the dip or inclination 
 of the needle. 
 
 12. In the northern hemisphere, it is tfie north pole 
 which dips, and in the southern hemisphere it is the 
 south pole. 
 
 13. To render a natural magnet capable of lifting a
 
 ^64 PNEUMATICS. 
 
 weight with the force of both poles, it is furnished with 
 an armature ; an artificial magnet, for the same purpose 
 is made in the form of a horse-shoe. 
 
 14. Soft iron receives magnetism with great facility 
 hut loses it almost immediately : steel on the contrary, 
 but especially hardened steel, is not easily affected ; but 
 the portion it receives, it permanently retains. 
 
 15. A magnet employed in the communication of 
 magnetism, rather gains than loses strength. 
 
 16. A steel bar, rendered magnetic, and resting by it3 
 centre upon a point, so as to be at liberty to turn in any 
 direction, is, with the box which contains it, and a card 
 on which are written the- names of the winds, called the 
 mariner's compass. 
 
 17. The azimuth compass differs chiefly from the 
 above in having two sights, through which may be seen 
 the sun or any heavenly body, of which the azimuth is 
 to be taken. 
 
 18. The dipping needle is made by accurately sus- 
 pending a bar of steel, in an unmagnetical state, on the 
 pivots of an axis passing through its centre ; it is then 
 magnetized, and dips according to the action of the north 
 or south pole upon it 
 
 PNEUMATICS. 
 
 THE science of Pneumatics treats of the density, pres- 
 sure, and elasticity of the air, and the effects which they 
 produce. 
 
 Pneumatics, being a science somewhat remote from 
 the present design of this work ; and having the proper- 
 ties of the air, under the head of chemistry ; we shall, 
 therefore, let an abstract of this science suffice. 
 
 Abstract of Pneumatics. 
 
 1. The air is the fluid which we breathe; with the 
 vapours it contains, it is called the atmosphere. 
 
 2. The particles of air are solid and impermeable, like 
 those of the hardest bodies.
 
 PNEUMATICS. 263 
 
 3. The air is invisible, because of its great trans- 
 parency; when unconfined it is imperceptible to the 
 touch, because its particles move among each other with 
 a facility so great that we perceive no force to be 
 required in displacing it ; we move in it as if we had no 
 pressure upon us, because its pressure is in every direc 
 tion the same. 
 
 4. The weight of air is to that of water, as 832 to 1. 
 
 5. The air expands in proportion to the diminution of 
 the pressure upon it ; it, therefore, becomes rare as we 
 ascend in the atmosphere : at the height of 3| miles, a 
 given bulk of it takes up twice the space it would do at 
 the surface of the earth. 
 
 6. The air-pump is a machine for exhausting the air 
 out of vessels ; but the best air-pumps have not so com- 
 pletely attained their object as to produce an absolute 
 vacuum, or place void of air. 
 
 7. The rising of water in common pumps, is owing to 
 the pressure of the atmosphere being removed from one 
 part of the fluid, which, therefore, yields at that part by 
 the pressure on the other parts, till the column of water 
 sustained is equal to the column of air sustaining it. 
 
 8. Suction, unless so applied as to mean the pressure 
 of the atmosphere, is a non-entity, and incapable of pro- 
 ducing effects. 
 
 9. The pressure of the atmosphere, which is in gen- 
 eral 15 Ibs. on every square inch, is not invariably the 
 same, but is in a middle-sized person 1866 pounds less at 
 one time than anothrr ; and when the pressure is greatest, 
 we feel exhilarated .-ather than depressed. 
 
 10. On the variable pressure of the atmosphere, and 
 the changes thereby occasioned, is founded the utility 
 of the barometer, by which instrument the pressure is 
 measured. 
 
 11. The best barometer is the common one, with a 
 straight tube, and short scale of variation ; other kinds, 
 in contriving which, the extension of the scale of variation 
 has been chiefly aimed at, are all more or less defective. 
 
 12. In observations for treasuring the height of moun- 
 
 23
 
 26G PNEUMATICS. 
 
 tains, a thermometer must be used along with the 
 barometer, in order that the due allowance may be 
 made for the effects of temperature in lengthening or 
 shortening the column of mercury ; and the surface of 
 the mercury in the cistern must be at a fixed distance 
 from the scale, before the height of the mercury is 
 read off! 
 
 13. The air may be condensed, or forced into less 
 compass than it occupies at the surface of the earth, by 
 means of a contrivance called a condensing engine. 
 
 14. When much condensed, the efforts of the air to 
 expand are so great, that it may be employed as a 
 powerful motive force. On this depend the properties 
 of air-guns. 
 
 15. An hygrometer v& an instrument for measuring the 
 dryness or moisture of the atmosphere. 
 
 16. De Saussure's hygrometer is made of clarified hair; 
 De Luc's, of a slip of whalebone cut across the grain. 
 
 17. The depth of rain which falls on the earth is esti- 
 mated by the quantity which falls within a small vessel 
 called a rain-gauge. 
 
 18. The strength of wind is measured by its power to 
 support bodies out of the position of equilibrium. 
 
 19. The winds are the consequences of variations con- 
 stantly taking place in the density of the atmosphere, 
 principally by the action of solar heat. 
 
 20. Variable winds are supposed to be the chief 
 causes of the rising and falling of the barometer, which, 
 in countries not subject to them, remains almost uniformly 
 at the same height. 
 
 21 In deriving from the barometer, prognostics of the 
 weatner, the tendency of the mercury to an upward or 
 downward motion, rather than its absolute height at any 
 time, is chiefly to be regarded. 
 
 22. When the air reaches the ear in a state of vibra- 
 .ory motion, it" occasions the sensations of sound. 
 
 23. Bodies which produce the clearest and strongest 
 sound, are in general the most elastic. 
 
 24. The quality of sound, in point of tone, is determi
 
 OPTICS- 267 
 
 ned by the greater or smaller number of vibrations made 
 by the sounding body in a given time. 
 
 25. Sonorous bodies, when sufficiently near, cause 
 each other to sound, although but one of them is struck, 
 provided they be in unison, or disposed to make vibra- 
 tions equally frequent. 
 
 26. An echo is the reflection of a sound, and cannot 
 be heard unless the original sound has traversed the 
 distance of about 110 feet. 
 
 27. Speaking and hearing trumpets act upon the 
 principle of reflecting towards their axes, and thereby 
 concentrating the sound transmitted through them. 
 
 OPTICS. 
 
 THIS is a branch of Natural Philosophy which treats 
 of the mechanical properties of light, and the .phenomena 
 of vision. 
 
 Abstract of Optics. 
 
 1. The particles of light, which are inconceivably 
 small, proceed from luminous bodies in right lines. 
 
 2. Consequently the density of light is inversely as the 
 square of the distance from the luminous centre. 
 
 3. Light moves at the rate of nearly 200,000 miles in 
 one second of time. 
 
 4. Its impression on the retina is not instantaneous; 
 hence though its particles may be separately projected, 
 so as to be, in their progress, at the rate of 1000 miles 
 apart, its velocity is sufficient to produce a distinct vision. 
 
 5. Every ray of light carries with it the image of the 
 point from which it was emitted ; when, therefore, pen- 
 cils of rays from every point of an object are united in 
 the same order in which they were emitted, they form 
 an image or representation of that object, at the place 
 where they are thus emitted. 
 
 6. All the rays of light, which enter another medium 
 obliquely, suffer refraction ; that is, they either move 
 farther from, or nearer to, the perpendicular, as the
 
 268 OPTICS. 
 
 medium into which they enter is rare_ or denser vhan 
 the other medium. 
 
 7. On the refrangibility of light depends the proper- 
 ties oF lenses. 
 
 8. Convex lenses collect the rays of light, and make 
 them converge to a centre or focus. 
 
 9. Concave lenses disperse the rays of light, the power 
 of refraction not being towards the centre, but towards 
 their circumference. 
 
 10. When light strikes upon a surface, it is reflected 
 so that the angle of reflection is equal to the angle of 
 incidence; on this the properties of mirrors depend. 
 
 11. Plane mirrors have no other effect than that of 
 changing the direction of the incident rays. 
 
 12. Convex mirrors cause parallel rays to diverge. 
 
 13. Concave mirrors collect parallel rays, or cause 
 them to converge to a focus. 
 
 14. Mixed mirrors exhibit distorted images, because 
 they increase or lessen the divergence or convergence of 
 the rays in one or two directions only. 
 
 15. The solar beam is composed of rays possessed of 
 different degrees of refrangibility, and these differences 
 of refrangibility, which are dependent on the size of 
 their particles, produce all the phenomena of colours. 
 
 16. The solar beam, or white light, contains rays of 
 seven different colours, viz. red, orange, yellow, green, 
 blue, indigo, and violet. These are called the primitive 
 colours, because they are immutable, except by inter- 
 mixture. 
 
 17. It is inferred that red light is composed of par- 
 ticles of the largest size, because it is found to be 
 capable of struggling through thick and resisting mediums, 
 which stop every other colour. 
 
 18. The size of the particles of other colours is in 
 the order of their enumeration, the violet being the 
 smallest. 
 
 19. The rainbow is owing to the separation of the 
 light into its primitive colours, by the drops of falling 
 rain, which act like a prism.
 
 OPTICS. 269 
 
 20. The rays of light are inflected when they pass 
 very near a body, and deflected when they pass at a 
 greater distance. 
 
 21. Those rays which deviate the least by refraction 
 deviate the most by flection. 
 
 22. The images of all visible, objects are depicted rn 
 the retina, in an inverted position. 
 
 23. With two eyes, vision is not only more distinct 
 but more accurate than with one. 
 
 24. A good eye can see most distinctly when the rays 
 fall exactly on the retina. 
 
 25. The best eye can hardly distinguish any object 
 that subtends an angle of less than half a minute. 
 
 20. The apparent magnitude of objects is dependent 
 on the angle under which they are seen, or the size of 
 their images depicted on the retina. 
 
 27. The long-sighted require convex spectacles, the 
 short-sighted, concave ones. 
 
 28. Burning lenses must be convex, and burning mir- 
 rors concave, as the effects of both these instruments 
 are dependent on the condensation of the incident light. 
 
 29. Microscopes are optical instruments for viewing 
 small objects. They appear to magnify objects, because 
 they enable us to see them with distinctness, nearer than 
 the natural limits of vision. 
 
 30. Refracting telescopes are formed by lenses only ; 
 when manufactured in the best manner, they are either 
 furnished with an acromatic object-glass, which corrects 
 the defect arising from the unequal refraction of the 
 different rays, by a combination of one or two convex 
 lenses with a concave one of a different sort of glass; or, 
 though more rarely, they have an aplanatic object- 
 glass, which corrects the same defect by a combination 
 of a plano-convex and meniscus glass, with a fluid be- 
 tween them that acts like a third lens. 
 
 31. Reflecting telescopes consist of lenses and at least 
 of one speculum. When there is more than one specu 
 lum, the second is only about one-fourth of the size of 
 the other, and may be either convex, concave, or plane. 
 
 23*
 
 270 ASTRONOMY. 
 
 32. Reflecting telescopes admit of a much greatei 
 magnifying power in a given length, than refracting 
 telescopes. 
 
 33. The binocular telescope consists of two telescopes 
 so combined, that both eyes may be employed in looking 
 at the same object. 
 
 ASTRONOMY 
 
 Is the science which treats of the motions, eclipses, 
 magnitudes, periods, and oHier phenomena of the heaven- 
 ly bodies. 
 
 Abstract of Astronomy. 
 
 1. The solar system comprises the sun and all the 
 bodies that revolve around him, viz : the comets, the 
 planets with their respective satellites, and the asteroids 
 
 2. The number of the comets is unknown ; that of 
 the planets, so far as yet discovered, is seven ; the satel 
 lites eighteen ; and the asteroids four. 
 
 3. The figure of the earth is not that of a perfect 
 globe, but an oblate spheroid, flattened a little at the 
 poles, by its revolution on its axis. 
 
 4. The planets Jupiter and Saturn are also observed 
 to be flattened at the poles like the earth, but in a great- 
 er degree, evidently because their diurnal revolution is 
 swifter. 
 
 5. The orbits of all the planets, asteroids, and comets, 
 are ellipses, having the sun in one of their foci ; but the 
 orbits of the two former classes of bodies are nearly 
 circular, while the orbits of the comets are all very 
 eccentric. 
 
 6. The orbits of the satellites are also ellipses, in one 
 of the foci of which is sustained the primary planet 
 round which they move. 
 
 7. The periods, distances, and magnitude of the planets, 
 have all been determined with very considerable exact- 
 ness; the same circumstances respecting the asteroids
 
 ASTRONOMY. 271 
 
 are also evidently determinable, though the results yet 
 laid down, have not, from the recent date of their dis- 
 covery, been so amply confirmed, as to be fully relied on; 
 'nit the comets recede to such immense distances, and 
 there is so much uncertainty in identifying them, that 
 their elements are hypothetical. 
 
 8. The planets, comets, and asteroids, are preserved 
 in their orbits, by the joint effects of the power of attrac- 
 tion, which acts in a right line from them to the sun, and 
 a projectile or centrifugal force, which would carry them 
 oil in a tangent to the curve of revolution. 
 
 9. The powers which preserve the satellites in their 
 orbits, are the same as those that act upon the planets 
 and comets, but the centripetal force is exercised by the 
 primary. 
 
 10. The body of the sun is supposed to be opaque, 
 ard to be surrounded with a double set of clouds, the 
 upper stratum of which forms the luminous globe we 
 behold. 
 
 11. The planets revolve roui,d an imaginary line or 
 axis within themselves, and the time in which they per- 
 form this rotation, constitutes their day and night. 
 
 12. The time in which a planet revolves round the 
 sun, forms its year. 
 
 13. The diversity of seasons is occasioned by the incli- 
 nation of the axes of a planet to the plane of its orbit. 
 
 14. The annual and diurnal revolutions of the planets 
 are all performed from west to east. 
 
 15. The satellites, also, revolve from west to east, with 
 the exception of the satellites of Herschel, which appear 
 to move in a contrary direction. 
 
 16. The fixed stars are distinguished from the bodies 
 af the solar system, by the twinkling light they afford, 
 ay their having no parallax, and by their having, even 
 through the best telescopes, no sensible magnitude. 
 
 17. The naked eye cannot behold above five hundred 
 turs in the whole hemisphere ; but the number dis- 
 wered with the assistance of a telescope exceeds all 
 calculation
 
 272 ASTRONOMY. 
 
 18. Every fixed star is supposed to be a sun, shining 
 by its own light, and surrounded by planetary worlds 
 like those of the solar system. 
 
 19. The tides are an effect of the attraction of the 
 sun and moon upon the ocean. When these luminaries 
 act together, or in the same line, they occasion spring 
 tides ; when they counteract each other's attraction, 
 neap tides take place. 
 
 20. Eclipses of the moon are owing to the shadow of 
 the earth falling upon the moon. 
 
 21. Eclipses of the sun occur, when the moon coming 
 between the earth and the sun, throws a shadow on the 
 earth. 
 
 22. Motion is the measure of time, and the motions of 
 the heavenly bodies are the basis by which all other 
 motions are measured. 
 
 23. The day is a natural division of time, that is, it 
 comprises a portion of time measured out by the com- 
 pletion of cerlrain phenomena, successive according to 
 regular laws. 
 
 The periodical and synodical lunar months are also 
 natural divisions of time, but no other ; the year, and 
 lunar and solar cycles, are of the same character as the 
 lunar months; the cycle of indiction, and the olympiad 
 We examples of the artificial division of time. 
 
 Thirty days hath September, 
 
 April, June, and November; 
 
 All the rest have thirty-one, 
 
 Except the leap-year : that 's the time, 
 
 When February's days- are twenty and nine.
 
 MECHANICAL EXERCISES. 275 
 
 is free from transverse fissures, or cracks in the edges, 
 and by a clear white, small grained, or rather fibrous 
 texture. The best and toughest iron is that which has 
 the most fibrous texture, and is of a clear greyish colour. 
 This fibrous appearance is given by the resistance which 
 its particles make* to separation. The texture of the 
 next best iron, which is also malleable in all tempera- 
 lures, consists of clear whitish small grains, intermixed 
 with fibres. Another kind is tough when it is heated, 
 but brittle when cold. This is called cold-short-iron, and 
 is distinguished by a texture consisting of large shining 
 plates, without any fibres. It is less liable to rust than 
 any other description of forged iron. A fourth kind of 
 iron called hot-short, is extremely brittle when hot, and 
 malleable when cold. On the surface and edges of the 
 bars of this kind of iron, transverse cracks or fissures 
 may be seen, and its internal colour is dull and dark. 
 
 The quality of iron may be much improved by violent 
 compression, as by forging and rolling, especially when it 
 is not long exposed to violent heat, which injures and at 
 length destroys its metallic properties. But though iron 
 is rendered malleable by hammering, this operation may 
 be continued so long as to deprive it of its malleability. 
 
 Steel is made of the purest malleable iron, by a pro- 
 cess called cementation. In this operation, layers of bars 
 of malleable iron, and layers of charcoal, are placed one 
 upon another, in a proper furnace, the air is excluded, 
 the fire raised to a considerable degree of intensity, and 
 kept up for 8 or 10 days. If, upon the trial of a bar, 
 the whole substance is converted into steel, the fire is 
 extinguished, and the whole is left to cool for G or 8 days 
 longer. Iron thus prepared is called blistered steel, from 
 the blisters which appear on its surface. In England, 
 charcoal alone is used for this purpose ; but Duame 
 found an advantage in using from one-fourth to one-third 
 of wood-ashes, especially when the iron was not of so 
 good a quality as to afford steel possessing tenacity t " 
 body as well as hardness. These ashes prevent the 
 steel-making process from being effected so rapidly as it
 
 276 MECHANICAL EXERCISES. % 
 
 would otherwise be, and give the steel pliability without 
 diminishing its hardness. The blisters on the surface of 
 the steel, under this management, are smaller and more 
 numerous. He also found that if the bars, when they 
 are put into the furnace, be sprinkled with sea salt, this 
 ingredient contributes to give body to the steel. If the 
 cementation be continued too long, the steel becomes 
 porous, brittle, of a darker fracture, more fusible, and 
 capable of being welded. On the contrary, steel cement 
 cd with earthy infusible powders is gradually reduced 
 to the state of forged iron again. Excessive or repeated 
 heating in the forge is attended with the same effect. 
 
 The properties of iron are remarkably changed by 
 cementation, and it acquires a small addition to its 
 weight, which consists of the carbon it has absorbed from 
 (he charcoal, and mounts to about the hundred-and- 
 liftieth, or two-hundreth part. It is much more brittle 
 and fusible than before ; and ii may still be welded like 
 bar-iron, if it has not been fused or over-cemented; but 
 by far the most important alteration in its properties is, 
 that it can be hardened or softened at pleasure. If it 
 be made red-hot, and instantly cooled, it attains a degree 
 of hardness which is sufficient to cut almost any other 
 substance; but, if heated and cooled gradually, it be- 
 comes nearly as soft as pure iron, and may, with much 
 the same facility, be manufactured into any determined 
 form. A rod of good steel, in its hardest state, possesses 
 so little tenacity, that it may be broken almost as easily 
 as a rod of glass, of the same dimensions. This brittle- 
 ness can only be diminished by diminishing its hardness; 
 and in the proper management of this point, for different 
 purposes, consists the art of tempering. The colours 
 which necessarily appear on the surface of the steel 
 slowly healed, are yellowish-white, yellow, or straw 
 colour, gold colour, brown, purple, violet, and deep blue. 
 These signs direct the artist in reducing the hardness of 
 steel to any particular standard. If steel be too hard, it 
 will not be proper for tools which are intended to have 
 * fine edge, because it will be so brittle, that the edge
 
 MECHANICAL EXERCISES. 277 
 
 will soon become notched : if, on the contrary, it be too 
 soft, it is evident that the edge \\ill turn or bend. Some 
 artists inclose the tools to be hardened in an iron case or 
 box, and slowly heat them to ignition ; they then take 
 the box out of the fire, and drop the pieces into \\ater, in 
 such a manner as will allow them to come as little as pos- 
 sible into contact with the air. This method answers two 
 good purposes; it causes the heat to be more equally 
 applied, and prevents the scaling occasioned by the con 
 tact of air. When the work has been polished, and 
 well defended from the air, it is, when hardened, nearly 
 as clear as before. If the tool be unpolished, they 
 brighten its surface upon a stone. It is then laid upon 
 burning charcoal, or upon the surface of melted lead, or 
 upon an ignited bar or plate of iron, till it appears the 
 desired colour ; at which instant, they plunge it into cold 
 water. The yellowish-white indicates a temper so little 
 reduced as to be used for edge-tools; the yellow, or straw 
 colour, the gold colour, and the brown, are used for pen- 
 knives, razors, and gravers ; the purple, for tools used in 
 \vorking upon metals, especially iron ; the violet, for 
 springs, and for instruments for cutting soft substances, 
 such as cork, leather, and the like ; but if the last blue 
 be waited for, the hardness of the steel will scarcely 
 exceed that of iron. When soft steel is heated to any 
 of these colours, and then plunged into water, it does not 
 acquire nearly so great a degree of hardness as if pre- 
 viously made quite hard, and then reduced by temper- 
 ing. The degree of ignition required to harden steel is 
 of different kinds. The best kinds require only a low 
 red heat. It has been ingeniously supposed, that the 
 hardness of steel depends on the intimate combination of 
 its carbon; and, on this supposition, it follows, that the 
 heat which effects this is the best, and that a higher de- 
 gree will be injurious. 
 
 The texture of steel is rendered uniform by fusion. 
 When it has undergone this operation, it is called cast- 
 steel ; which is wrought with more difficulty than com- 
 mon steel, because it is more fusible, and is dispersed 
 24
 
 278 MECHANICAL EXERCISES. 
 
 under the hammer, if heated to a white heat. The cast 
 steel of England is made from the fragments of the 
 crude steel of the manufactories and steel works. A 
 crucible, about ten inches high and seven inches in dia- 
 meter, is filled with the fragments, and placed in a 
 wind furnace, like that of the foundries, but smaller, 
 because intended to contain one pot only. It is, like- 
 wise, furnished with a cover and chimney, to increase 
 he draught of the air. The furnace is entirely filled 
 with coke, and five hours are required for the perfect 
 fusion of the steel. It is then cast into ingots, and after 
 wards forged in the same manner as other steel, but with 
 less heat and more precaution, as it is more liable tc 
 break. Cast steel is becoming more and more in use 
 but must necessarily be excluded from many works of 
 considerable size, on account of the difficulty of welding 
 it, and the facility with which it is degraded in the fire. 
 Cast steel takes a fine firm edge, and receiving an 
 exquisite polish, of which no other sort of steel is, in so 
 high a degree, susceptible, it is made use of for all the 
 finest cutlery in England ; it is too imperfectly fluid to 
 De cast into small wires. The tenacity of steel ham- 
 mered at a low heat, or even when cold, is considerably 
 increased ; but the effect of the hammering is taken ofl 
 by strong ignition. Tools, therefore, made of cast steel 
 and intended to sustain a good edge, for cutting iron and 
 other metals, are not afterwards softened, but the ignition 
 is carefully regulated at first, as the most useful hardness 
 is produced by that degree of heat which is just suf- 
 ficient to effect the purpose. Cast steel, annealed to a 
 straw colour, is softened nearly as much as other kinds tc 
 a purple or blue. 
 
 Various methods of hardening steel are resorted to 
 such as oil, tallow, urine, and other saline liquids; soaj 
 in solution produces a similar effect. But when steel L 
 required to possess the greatest degree of hardness, it 
 may be quenched in mercury, which will render it so 
 Lard as to cut glass like a diamond. 
 
 Wrought iron may be hardened, in a small degree, by
 
 MECHANICAL EXERCISES. 279 
 
 ignition and plunging into water, but the effect is con- 
 fined to the surface ; except, as very often happens, the 
 iron contains veins of steel. 
 
 The surest method for selecting steel for edge tools, is, 
 to have one end of the bar drawn out under a low heat, 
 such as an obscure red, and then to plunge it suddenly, 
 at this heat, into a pure cold water. If it prove hard, 
 for instance, if it will easily cut glass, and require a 
 great force to break it, whatever its fracture may be, it 
 is good, the excellence of steel being always proportion- 
 ate to the degree of its tenacity in its hard state : in 
 general a neat curved line fracture, and even grey tex- 
 ture, denote good steel, and the appearance of threads, 
 cracks, or brilliant specks, is a proof of the contrary. 
 
 If diluted nitrous acid (aquafortis) be applied to the 
 surface of steel previously brightened, it immediately 
 produces a 'black spot, but if applied to iron, in like 
 manner, the metal remains clear. By this method it 
 will be easy to select such pieces of iron or steel as pos- 
 sess the greatest degree of uniformity ; as the smallest 
 vein of either upon the surface, will be distinguished by 
 its peculiar sign. 
 
 The hardness and polish of steel may be united, in a 
 certain degree, with the firmness and cheapness of 
 malleable iron, by what is called case-hardening, an 
 operation much practised, and of considerable use. It 
 is a superficial conversion of iron into steel, and only 
 differs from cementation in being carried on for a shorter 
 time : some artists pretend to great secrets in the prac- 
 tice of this art', using saltpetre, sal ammoniac, and other 
 fanciful ingredients, to which they attribute their success. 
 Cut it is now an established fact, that the greatest effect 
 may be produced by a perfectly tight box, and animal 
 carbon alone. 
 
 The goods intended to be case-hardened, being pre- 
 viously finished with the exception of polishing, are 
 stratified with animal carbon, and the box containing 
 them luted with equal parts of sand and clay. They 
 are then placed in the fire, and kept in a light-red heat
 
 280 MECHANICAL EXERCISES. 
 
 for half an hour, when the contents of he box are 
 emptied into water. Delicate articles may be preserved 
 like files, by a saturated solution of common salt with 
 any vegetable mucilage to give it a pulpy consistence. 
 The carbon here spoken of, is nothing more than any 
 animal matter, such as horns, hoofs, skins, or leather, 
 just sufficiently burnt to admit of being burnt to powder. 
 The box is commonly made of iron, but the use of it 
 for occasional case-hardening upon a small scale may b 
 easily dispensed with ; as it will answer the same end t 
 envelope the articles with the composition above direct- 
 ed to be used as a lute, drying it gradually, before it is 
 exposed to a red heat, otherwise it will probably crack. 
 It is easy to infer, that the depth of thfc steel induced by 
 case-hardening, will vary with the time the operation is 
 continued. In half an hour it will scarcely be the 
 thickness of a six-cent piece, and therefore will be re- 
 moved by the violent abrasion, though sufficient to 
 answer well for fire-irons, &c., in the common usage of 
 which its hardness prevents its being easily scratched, 
 and its polish is preserved by friction with so soft a ma 
 terial as leather. 
 
 The blueing of steel has a remarkable influence on 
 its elasticity. This operation consists in exposing steel, 
 the surface of which has been brightened, to the regu- 
 lated heat of a plate of metal, or of a fire, or lamp, till 
 the surface has acquired a blue colour. If this blue 
 colour, so commonly considered rather as ornamental 
 than useful, be partially or wholly removed, by grinding 
 or in any other manner, the elasticity is 'proportionately 
 impaired, and the original excellence of this property 
 can only be restored by blueing the steel again. Saw 
 makers first harden their plates in the ustial way, in 
 which state they are brittle and warped ; they then 
 soften them by blazing, which consists in smearing the 
 plate with oil or grease, and heating it till thick vapours 
 are emitted, and burn off with a blaze. They then 
 hammer them flat, and afterwards blue them on a hot 
 ron, which renders them stiff and elastic without alter- 
 ing their flatness.
 
 MECHANICAL EXERCISES. 281 
 
 Steel expands its dimensions, in a small degree, by 
 hardening. It is a curious fact, that intense cold has 
 an unfavourable effect on steel ; so that, in severe frosls, 
 workmen often find their tools incapable of receiving the 
 temper they wish. 
 
 A slender rod of wrought iron may be expeditiously 
 converted into steel, by plunging it into cast iron in fu- 
 sion ; a satisfactory proof that cast iron contains the steel- 
 making principle, which, we need not repeat, is carbon. 
 In fact, as it is principally in the superabundance of its 
 carbon that it differs from steel, many attempts, (and 
 not without success,) have been made to convert it into 
 the latter, without the intermediate operation of render- 
 ing it malleable. But the best steel made pursuant tc 
 this idea, is very imperfect. It is, however, not unim- 
 portant to observe, that all cast iron so far resembles 
 steel, as to be hardened in a high degree by sudden cool- 
 ing, which imparts to it, at the same time, whiteness of 
 colour, brittleness, and closeness of texture. This pro- 
 perty of crude^ iron may be advantageously employed or 
 many occasions ; for instance, in the fabrication of axles 
 and collars of wheels, which are closely turned or filec" 
 in a thin soft state, and may afterwards be hardened, so 
 as to wear admirably well. 
 
 The heat applied to cast iron, previously to its being 
 plunged into the water to harden, is greater than that tc 
 which steel is subjected for the same purpose. Cast iron 
 also, when once hardened, admits not, like steel, of that 
 hardness being reduced, bv various gradations, to any 
 specific degree ; to soften it materially, it must be sub- 
 mitted, for some time, to a complete ignition, and very 
 gradually cooled. 
 
 ANEALING. 
 
 Lv a considerable number of instances, bodies which 
 are capable of undergoing ignition, are rendered hard 
 and brittle by sudden cooling. Glass, cast iron, and steel, 
 are the most remarkably affected by this circumstance ; 
 the inconveniences arising from which are obviated by 
 24*
 
 282 MECHANICAL EXERCISES. 
 
 cooling them very gradually, and this process is called 
 annealing. Glass vessels are carried into an oven over 
 the great furnace called the leer, where they are per- 
 mitted to cool, in a greater or less time, according to 
 their thickness and bulk. Steel is most effectually 
 anealed by making it red-hot in a charcoal fire, which 
 must completely cover it, and be allowed to go out of its 
 own accord. Cast iron, which may require to be an- 
 nealed in too large a quantity, to render the expense of 
 charcoal very agreeable, may be heated in a cinder fire, 
 which must completely envelope and defend the pieces 
 from the air till they are cold. The fire need not be 
 urged so as to produce more than a red heat; a little 
 beyond this, bars and thin pieces would bend, if destitute 
 of a solid support ; and would even be melted without 
 any vehement degree of heat. If it be required to aneal 
 a number of pieces expeditiously, and the fire is not 
 large enough to take more than one or two of them at 
 once ; or if it be thought hazardous to leave the fire to 
 itself, from an apprehension that the heat jnight increase 
 too much, the following scheme may be adopted : heat as 
 many of the pieces at once as may be convenient, and 
 as soon as they are red-hot, bury them in the dry saw- 
 dust. Cast iron, when anealed, is less liable to warj 
 by a subsequent partial exposure to moderate degree* 
 of heat, than that which has not undergone this opera- 
 tion. 
 
 The above methods of anealing render cast iron easy 
 to work, but do\ not deprive it of its natural character 
 Cast iron cutlery is, therefore, stratified with some sub- 
 stance containing oxygen, such as poor iron ores, free 
 from sulphur, and kept in a state little short of fusion for 
 twenty-four hours. It is then found to possess a consider- 
 able degree of malleability, and is not unfit for several 
 sorts of nails and edge-tools. 
 
 Copper forms a remarkable exception to the general 
 rule of anealing. This metal is actually made softer 
 and more flexible by plunging it, when red-hot, into cold 
 water, than by any other means. Gradual cooling p> * 
 dures a contrary effect.
 
 MECHANICAL EXERCISES. 283 
 
 COPPER. 
 
 WE refer to the article of chemistry for a minute enu- 
 meration of the whole of the known metals; but in this 
 place, we shall, with the exception of iron, which has 
 already been noticed, introduce a general practical view 
 of the properties, applications, and combinations with 
 each other, of those most frequently occurring in common 
 arts and common life. Making this our plan, the firs 
 object that claims our attention is copper. 
 
 Copper is a very brilliant, sonorous metal, of a fine 
 colour, possessing a considerable degree of hardness and 
 elasticity. It is extremely malleable, and may be re- 
 duced to leaves so fine, that they may be carried about 
 by the wind. Its tenacity is very great. A wire of 
 one-tenth of an inch in diameter will support a weight 
 equal to 300 Ibs. avoirdupois, without breaking. It does 
 not melt till the temperature is elevated to about 27 of 
 Wedgwood ; or, (by estimation) 14.50 of Fahrenheit. 
 When rapidly cooled, it exhibits a granulated and porous 
 texture. When the texture is raised beyond what is 
 necessary for its fusion, it is sublimed in the form of visi- 
 ble fumes. Its greatest malleability is at a low red heat. 
 None of the malleable metals are so difficult to file, or 
 turn smooth, as copper; but it is cut by the graver, or 
 ground by gritty substances, with great ease. 
 
 When miners wish to know whether an ore contains 
 copper, they drop a little nitric acid upon it ; after a 
 little lime, they drop a feather into the acid, and wipe it 
 over the polished blade of a knife; if there be the 
 smallest quantity of copper in it, this metal will be pre- 
 cipitated upon the knife, to which it will impart a pecu- 
 liar colour. Roman vitriol, much used by dyers, and in 
 many of the arts, is a sulphate of copper. A solution of 
 this salt is used for browning fowling-pieces and tea-urns, 
 In domestic economy, the necessity of keeping copper 
 vessels perfectly clean, cannot be too strongly inculcated 
 but it is worthy of remark that fat and oily substances 
 and vegetable acids do not attack copper while hot; arid,
 
 284 K MECHANICAL EXERCISES. 
 
 therefore, copper vessels may be used, for culinary pur- 
 poses, with perfect safety, if no liquor be ever suffered 
 to grow cold in them. The mere tinning of copper and 
 brass vessels does not ajlbrd complete safety, as it is nevei 
 so perfect as to cover every part. 
 
 Compounds formed by the mixture of two or more 
 different metals are called alloys. The alloys of copper, 
 especially those in which this metal predominates, are 
 more numerous in the arts than those of any other 
 metal. Many of them are perfectly well known, and have 
 been immemorial!)- in use. The exact composition, and 
 particularly the mode of preparing several, are kept as 
 secret as possible. By the aid of chemistry, we may 
 detect the exact composition of an alloy ; yet we may 
 not always be able, by common methods, to produce a 
 mixture having all the excellencies, which perhaps, 
 mere accident has taught the possessor of the secret to 
 combine. 
 
 Brass is the most important of all the alloys of copper. 
 It is more fusible than copper, less liable to tarnish from 
 exposure to the atmosphere, and its fine yellow colour is 
 more agreeable to the eye. It is much more malleable 
 than copper, when cold, but less malleable when hot; at 
 a low red heat, it crumbles under the hammer. Sieves 
 of extreme fineness are woven with brass wire, after the 
 manner of cambric weaving which could not possibly be 
 made with copper wire. Three parts of copper and one 
 of calamine, or native carbonate of zinc, constitute brass. 
 The calamine is first pounded in a stamping mill, and 
 then washed and sifted, in order to separate the lead 
 with which it is mixed. It is then calcined on a broad, 
 shallow brick earth, over an oven heated to redness, and 
 frequently stewed for some hours. In some places, it is 
 calcined in a kind of kiln, filled with alternate layers of 
 calamine and charcoal, and kindled from the bottom, 
 where a sufficient quantity of wood has been deposited 
 for the purpose. When the calamine has been thoroughly 
 calcined, it is ground in a mill, and mixed at the same 
 time with a third or a fourth part of charcoal, and is
 
 MECHANICAL EXERCISES. 283 
 
 then ready for the brass furnace. Being put into cru 
 cibles with the requisite proportion of grain copper 
 copper chippings, or refuse bits of various kinds, the 
 whole is covered with charcoal, and the crucibles luted 
 up with a mixture of clay or loam and horse-dung. The 
 heat employed, is, for a considerable time, not sufficient 
 to melt the copper, which is at length raised so as tc 
 fuse, and the compound metal is then run into ingots. 
 
 In general, the extremes of the highest and lowest 
 proportions of zinc are from twelve to twenty-five per 
 cent, of zinc ; brass is perfectly malleable, if well man- 
 jfactured, though zinc itself scarcely yields to the hammer 
 it common temperatures. 
 
 Good brass, when received from the foundry, is nearly 
 inelastic, but exceedingly flexible, and when polished, 
 the naked eye cannot discover any pores, which are fre- 
 quently observable in the inferior kinds. The liberal 
 use of the hammer imparts a considerable portion of 
 elasticity to brass, and renders it at the same time less 
 flexible. Clock-makers, watch-makers, and all artists who 
 employ this metal, put it in forms that admit of hammer- 
 ing it well before they turn or file it ; otherwise their 
 work would wear indifferently, and a trifling cause injure 
 its figure. Brass is not malleable when ignited. 
 
 Hammering is found to give a magnetic property to 
 brass, perhaps occasioned by the minute particles of iron 
 separated from the hammer and the anvil during the 
 process, and forced into its surface. This circumstance 
 makes it necessary to employ unhammered brass for 
 compass boxes and similar apparatus. 
 
 Five or six parts of copper and one of zinc, form a 
 pinchbeck. Tombac has still more copper, and is of a 
 deeper red than pinchbeck. Prince's metal is a similar 
 compound, excepting that it contains more zinc than 
 either of the former. 
 
 The alloys of copper with different proportions of tin, 
 are of great importance in the arts. They form com- 
 pounds which have distinct and appropriate uses. Tip 
 renders copper more fusible, less liable to rust, harder
 
 286 MECHANICAL EXERCISES. 
 
 denser, and more sonorous. Copper and tin separately 
 are not more remarkable for their ductility, than, when 
 united, the compounds they form are for their brittleness. 
 
 Eight to ten .parts of tin, combined with one hundred 
 parts of copper, form bronze, which is of a greyish 
 yellow colour, harder than copper, and the usual compo- 
 sition for statues. 
 
 The customary proportions for bell-metal are, three 
 parts of copper and one of tin. The greater part of the 
 tin may be separated by melting the alloy, and then 
 throwing a little water upon it. The tin decomposes the 
 water, is oxidized, and thrown upon the surface. The 
 proportion of tin in bell-metal is varied a little at differ- 
 ent foundries, and for different sorts of bells. Less tin is 
 used for large bells than smaller ones, and for very small 
 ones, a trifling quantity of zinc is used, which renders 
 the composition uiore sonorous, and it is still further 
 improved in this respect by a little silver being added. 
 
 A small quantity of antimony is occasionally found in 
 bell-metal. When copper, brass, and tin, are used to 
 form bell-metal, the copper is from seventy to eighty per 
 cent, including the proportion contained in the brass, and 
 the remainder is tin and zinc. When tin is nearly one- 
 third of the alloy, it is then beautifully white, with a 
 lustre almost like mercury, extremely hard, close-grained, 
 and brittle; but when the proportion of tin is one-half, 
 it possesses these properties in a still more remarkable 
 degree, and is susceptible of so exquisite a polish, as to 
 be admirably adapted for the speculums of telescopes. 
 If more tin be added than amounts to half the weight 
 of the copper, the alloy begins to lose that splendid 
 whiteness for which it is so valuable as a mirror, and 
 becomes of a blue grey. As the quantity of tin is in- 
 reased, the texture becomes rough-grained, and totally 
 unfit for manufacture. 
 
 OF TIN. 
 
 TIN is a metal of considerable importance in the arts. 
 It is of a silver-white colour, very Ductile, malleable, and
 
 MECHANICAL EXERCISES. 287 
 
 gives out while bending, a peculiar crackling noise. Its 
 specific gravity is 7.291 ; a cubic foot weighs about 
 516 Ibs. avordupois. Its purity is in proportion to its 
 levity. It melts at the 400th degree of Fahrenheit's ther- 
 mometer, and promotes the fusibility of the metals with 
 which it is mixed. Two parts lead and one of tin form 
 plumbers' solder, which melts sooner than either of the 
 metals separately. Eight parts of bismuth, five of lead, 
 and three of tin, form a metal which melts at a heat 
 not exceeding that of boiling water. 
 
 Tin is used to form boilers for dyers, and worms for 
 rectifiers' stills. The common mixture for pewter is 112 
 Ibs. of tin, 15 Ibs. of lead, and 6 Ibs. of brass. But the 
 name of pewter is given to any malleable white alloy 
 into which tin largely enters; and perhaps no two manu- 
 facturers employ the same ingredients in the same pro- 
 portions. The finest kinds of pewter contain no lead 
 whatever ; but consist of tin, with a small quantity of 
 antimony, and sometimes, a little copper. Pewter may 
 be used for vessels containing wine, and even vinegar 
 provided the tin constitutes three-fifths of the alloy. 
 
 The consumption of tin, in the operation called tinning, 
 is very considerable. The principal secret in tinning is, 
 to preserve the tin and surface of the metal to which it 
 is intended to be applied, perfectly clean, and in a pure 
 metallic state. Thin plates or sheets of iron, which, 
 when coated with tin, are so well known under the 
 name of tin-plates, white iron, or latten, are prepared by 
 scouring them with sand. They are then immersed iu 
 water, acidulated with sulphuric acid, in which they are 
 kept for twenty-four hours, being occasionally turned 
 during that time, so that they may rust equally in every 
 part. When taken out, they are scoured, and made 
 perfectly clean; they are then dipped in pure water, 
 and kept till wanted for tinning. The tin is melted in 
 an iron crucible, narrow, but deeper than the length of 
 the iron plates, which are plunged in downright, so that 
 the tin swims over them. The surface of the tin, to 
 prevent its oxidation, is covered with some oily or resin 
 ous matter.
 
 288 MECHANICAL EXERCISES. 
 
 Reaumur states, that the Germans cover it with suel 
 previously prepared by frying and burning, which sur- 
 prisingly puts the iron in a condition to receive the tin. 
 The melted tinmust also have a certain degree of heat. 
 If not hot enough, it will not adhere to the iron ; and, if 
 it be too hot, the coat will be very thin, and the plates 
 discoloured. Plates intended to have a very thick coat, 
 are -first dipped into the crucible when the tin is very 
 hot, and afterwards, when it is cooler. For the second 
 dipping, the suet must not be prepared, but used in its 
 common state. The tin not only adheres to the surface 
 of iron plates, but penetrates, and intimately combines 
 with them. 
 
 Copper is tinned after it has been formed into utensils. 
 If the copper be new, its surface is first scoured with 
 salt and diluted sulphuric acid ; pulverised resin is then 
 thrown over the interior of the vessel, into which, after 
 heating it to a considerable degree, a sufficient quantity 
 of melted tin is poured, and spread upon it, by means of 
 a rod of hard-twisted flax ; which renders the coating 
 uniform. Pure tin is rarely used for this purpose; it is 
 generally, though injuriously, alloyed with a small pro- 
 portion of lead. The use of the resin is important ; for 
 the heat given to the copper is sufficient to oxidize its 
 surface in some degree ; and an alteration of this sort, 
 however slight, would prevent the perfect adhesion of 
 the tin. The resin is equally useful in preventing the 
 partial oxidation of the tin, or in reviving the small par- 
 ticles of oxide which may be formed during the ope- 
 ration. 
 
 For tinning old vessels a second time, the surface is 
 first scraped clean and bright with a steel instrument, 01 
 scoured with iron scales, then pulverised salammoniac is 
 strewed over it, and the melted tin is rubbed on the sur 
 face with a solid piece of salammoniac. 
 
 The process for covering iron vessels with tin, corre- 
 sponds with that last described ; but they ought to be 
 previously cleaned with the muriatic acid, instead of 
 being scraped or scoured. Iron nails which cannot b*
 
 MECHANICAL EXERCISES. 289 
 
 conveniently tinned in a bath, are easily covered with tin 
 by including them, with a due proportion of tin and 
 salammoniac, in a stone bottle, and agitating them while 
 heating and cooling. 
 
 The following method of tinning is highly esteemed for 
 its permanency and beauty : the utensil is cleaned in the 
 usual manner ; its inner surface is beaten on a rough 
 anvil, or scratched with a wire-brush, that the tinning 
 may adhere more closely to the copper ; and one coat of 
 fine tin is then laid on with salammoniac as abfcve directed 
 for tinning old copper. A second coat consisting of two 
 parts of tin and three of zinc, must next be uniformly 
 applied with salammoniac, in a similar manner : the sur- 
 face is now to be beaten; scoured with chalk and water; 
 smoothed with a proper hammer ; exposed to a moderate 
 heat ; and lastly dipped in melted tin. This sort of tin- 
 ning effectually prevents the utensils from rusting. 
 
 Pins are whitened by filling a pan with alternate lay- 
 ers of them and grain-tin. A solution of super-tartrate 
 )f potass, (cream of tartar) is then poured upon them, 
 and they are boiled for four or five hours. The tartaric 
 acid first dissolves the tin, and then gradually deposits it 
 on the surface of the pins, in consequence of its greater 
 affinity for the zinc which enters into the composition of 
 the brass wire. 
 
 There are two kinds of tin known in commerce ; viz. 
 block tin, and grain tin. Block tin is procured from the 
 common tin ore ; grain tin is found, in small particles, in 
 what is called stream tin ore. It owes its superiority not 
 only to the purity of the ore, but to the care with which 
 it is washed and refined. 
 
 OF LEAD. 
 
 LEAD unites with most of the metals. It has little 
 elasticity, and is the softest of them all. Gold and silver 
 are dissolved by it in a slight red heat ; but, when the 
 heat is much increased, the lead separates, and rises to 
 the surface of the gold, combined with all heterogeneous 
 25 T
 
 290 MECHANICAL EXERCISES. 
 
 matters. This property of lead is made use of in the 
 art of refining the precious metals. 
 
 If lead be heated so as to boil and smoke, it soon dis- 
 solves pieces of copper thrown into it: the mixture, 
 when cold, is brittle. The union of these two metals 
 is remarkably slight ; for, upon exposing the mass to a 
 heat no greater than that in which lead melts, the lead 
 almost entirely runs off by itself. This process, which 
 is peculiar to lead with copper, is called eJiquation. It 
 has lately been discovered, that a certain preparalion 
 of lead may be mixed with the metal formerly used for 
 white metal buttons, without injuring the appearance; 
 thus affording a considerable addition of profit to the 
 manufacturer. 
 
 The consumption of lead for water-pipes, cisterns, and 
 to cover buildings, is very extensive. Sheet-lead is made 
 by suffering the melted metal to run out of a box through 
 a long horizontal slit, upon a table prepared for the pur- 
 pose. The table is generally covered with sand, and 
 the box is drawn over it by appropriate ropes and pul- 
 leys, leaving the melted lead behind, to congeal in the 
 desired form. The requisite uniformity and thinness are 
 given to these sheets, by rolling them between two cylin- 
 ders of iron, acting upon the same principle as the cop- 
 per-plate printing-press. 
 
 The alloy of lead and antimony is used for printers* 
 types. Chaptal made a great variety of experiments to 
 ascertain the best proportions of these metals to each 
 other for this use. He always found four parts of lead 
 and one of antimony form the most perfect composition. 
 But, if the antimony be pure, one part of it, to seven or 
 eight of lead, form an alloy too brittle to be extended 
 under the hammer, and as hard as the generality of 
 types. To g^'ve hardness to the lead, is not the only use 
 of antimony in this composition. It renders the lead 
 more fusible, more fluid when melted, and, as it expanda 
 in passing to a solid state, it is calculated to produce a 
 sharper impression of the mould than could be easily 
 obtained by lead alone. Antimony, (which in trade is
 
 MECHANICAL EXERCISES. 291 
 
 sometimes called regulus of antimony, or regulus, only,} 
 requires, when alone, much more heat for its fusion than 
 lead, in combining with which metal, as it is little more 
 than half its weight, it rises to the surface, and requires 
 to be well stirred before it will incorporate. Different 
 parts of the same block of type-metal often possess dif- 
 ferent degrees of hardness. In melting lead for shot, a 
 email quantity of arsenic is added, to cause it to run into 
 spherical drops. The arsenic is generally added in ex- 
 cess to a small quantity of lead, which is covered and 
 closely luted till the incorporation is complete. The 
 compound is called slag, or poisoned metal. Ingots of 
 this slag are then added to soft pig-lead, in such propor- 
 tion as is found, upon trial, to cause it to drop in a globu- 
 lar form. 
 
 The surface of melted lead, as every one knows, be- 
 comes quickly covered with a skin or pellicle, often 
 assuming different lively hues at first, and subsequently 
 increasing in quantity and darkness of colour. This 
 effect is termed by chemists, oxidation, as it is occasioned 
 by the action of oxygen of the atmosphere, the activity 
 of which is greater in proportion to the heat of the lead, 
 and wastes the metal so fast, that it becomes an object of 
 importance to those who melt much lead, to check its 
 formation, or to convert it, when formed, by the cheapest 
 process into the metallic state again. A thick coating 
 of ashes of any kind will check the formation of the 
 oxide, and may be easily pushed back, when a quantity 
 of lead must be taken out of the crucible or melting-pan. 
 Charcoal, which is also a good covering for lead hi the 
 pan, will convert dross into metal, when assisted oy a 
 sufficient heat ; fat, oily, and bituminous substances in 
 general, have a similar effect. Common resin answers 
 exceeding well ; thrown in powder upon melted lead, 
 and stirred about, it immediately converts the oxide into 
 metal, causes the surface to shine like mercury, and if any 
 thing remains, it is only a black dirt, with small globules 
 of pure lean, skimmed off at the same time, yet mixed 
 with it; by throwing it into water, stirring it thoroughly
 
 292 MECHANICAL EXERCISES. 
 
 and pouring off all that does not immediately sink, these 
 grains may be separated. If part of what appears to 
 be dirt, is found to be so heavy, as instantly to sink to 
 the bottom of water, it may be suspected to be true dross 
 or oxide, and may be revived by mixing it with charcoal, 
 and exposing it to a considerable heat. It is always, 
 however, more prudent and economical to use means oil 
 preventing the formation of oxide, than to bestow much 
 time upon its revival. 
 
 Lead becomes less fluid every time it is melted, and by 
 much or frequent exposure to a high "temperature, a 
 state "in -which it is said to be rotten, is superinduced. 
 To use new lead, and not melt it oftener, or expose it to 
 a greater heat than is indispensable, are necessary pre- 
 cautions to preserve this metal in its best state. Plumbers, 
 when they cast it into sheets, strew common salt upon 
 the table, to facilitate its spreading, when they are not 
 using new lead, and are for that, or any other reason, 
 apprehensive that it will not run well. 
 
 The observations above recited on the management 
 of lead, apply with equal propriety, to tin, antimony, 
 zinc, bismuth, &c., and all the alloys of these metals 
 with lead or each other. In fact, as lead is so much 
 cheaper than the other metals just enumerated, the ob- 
 ject of saving it from destruction is proportionately of 
 less consequence. 
 
 OF ZINC. 
 
 Ziivc is a very combustible metal, of a bluish, brilliant 
 white colour. It seems to form the link between the 
 brittle and the malleable metals. It is a modern dis- 
 covery, that at a temperature of from 210 to 300 of 
 Fahrenheit, it yields to the hammer, may T>e drawn into 
 wire, or extended into sheets. After having been thus 
 annealed, it continues soft, flexible, and extensible, and 
 does not return to its partial brittleness; thus admitting 
 of being applied to many uses for which zinc was for- 
 merly deemed unfit. 
 
 There can now be KK> difficulty in forming zinc inte
 
 MECHANICAL EXERCISES. '^93 
 
 sheathing for the bottoms of ships, into vessels of capa- 
 city, water pipes, and utensils for various manufactories. 
 As an internal lining for ordinary vessels, instead of tin, 
 it has been applied with success. It is much harder and 
 cheaper than tin, and may be spread very uniformly. 
 
 Zinc at a very elevated temperature, may be pulver- 
 ized. It may also, like several other metals, be minutely 
 divided, by pouring it, when in fusion, into water. These 
 are the most convenient means of reducing it into small 
 particles. Files have no considerable action upon it ; 
 besides, it wears and chokes them up in a short time. 
 Zinc, in filings or small particles, is used to produce those 
 brilliant stars and spangles which are seen in the best 
 artificial fire-works ; but the filings of cast iron produce, 
 at a cheaper rate, an effect scarcely inferior. 
 
 Calamine, or lapis calaminarus, used in converting 
 copper into brass, is found in masses and in a crystallized 
 state, and is generally combined with a large portion of 
 silex. It is a native oxide of zinc, combined with car- 
 bonic acid. Zinc is also found in an ore called blena, or 
 as the miners term it, Black Jack. It is a sulphuret of 
 zinc : in Wales, it was employed formerly in mending 
 the roads. 
 
 SOLDERING. 
 
 To unite two pieces of the same or different metals, 
 by fusing some metallic substance upon them, is called 
 soldering. It is a general rule, that the solder should be 
 easier of fusion than the metal to be soldered by it. It 
 is, in the next place, desirable, though seldom absolutely 
 necessary, nor always attempted, that the solder and the 
 metal to which it is intended to be applied, should be of 
 the same colour, and of the same degree of hardness and 
 malleability. 
 
 Solders are distinguished into two different classes, viz. 
 the hard and the soft solders. For the hard solders, 
 which are ductile, and admit of being hammered, some 
 of the same sort of metal as that to be soldered, is, in 
 the greatest number of instances, alloyed with 
 25*
 
 294 MECHANICAL EXERCISES. 
 
 other which increases its fusibility. Some of the facts 
 already detailed, respecting the metals, prove that the 
 addition made with this view need not always be itself 
 easier of fusion. 
 
 The solder for platina is gold, and the expense of it 
 will, therefore, contribute to hinder the general use of 
 platina vessels, even in chemical experiments. 
 
 The hard solder for gold, is composed of gold and 
 silver: gold and copper; or gold, silver, and copper 
 Goldsmiths usually make four kinds, viz. solder of eight, 
 in which, to seven parts of silver, there is one of brass 
 or copper ; solder of six, where only a sixth part is cop- 
 per ; solder of four, and solder of three. But many who 
 may have occasion to solder gold, cannot encumber them- 
 selves with these varieties. 
 
 For general purposes, therefore, the following composi- 
 tion may be provided ; melt two parts of gold, with one 
 )f silver and one of copper; stir the mass well to make 
 it uniform, add a little borax in powder, and pour it out 
 immediately. If cast into very thin narrow slips, it will 
 be the more handy for subsequent use. To cleanse gold 
 which has been soldered, heat it almost to ignition, let it 
 cool, and then boil it in urine and sal ammoniac. 
 
 The hard solder for silver may be prepared by melting 
 two parts of silver with one of brass. It must not be 
 kept long in fusion, lest the zinc of the brass fly off iu 
 fumes. If the silver to be soldered, be alloyed with 
 much copper, the proportion of brass may be increased ; 
 for example, the following composition may be used ; foui 
 parts of silver and three of brass, rendered easy of fusion 
 by a sixteenth part of zinc. Silver which has been sol- 
 dered, may be cleaned by heating it, and letting it cool, 
 as directed for gold, but it must be boiled in alum water 
 
 The hard solder for copper and brass, is a soft fusible 
 sort of granulated brass, known to artists by the name 
 of speltre. It consists of brass mixed with an eighth, 
 or a sixth, or even one-half of zinc. The braziers use 
 no other kind of hard solder. As sptltre melts sooner 
 than common brass, it serves for the solder of the latter 
 as well as for copper.
 
 MECHANICAL EXERCISES. 295 
 
 Standard silver makes an excellent solder for brass; 
 ft is more fusible than speltre, proportionately easier to 
 manage, and equally as durable. A slight demand "for 
 silver solder, may, to many, be supplied at a cheap rate, 
 in consequence of the number of the small silver articles 
 in use, and which are frequently wearing out. 
 
 Iron may be soldered with copper, gold, or silver 
 Brass or speltre is most commonly used, and the opera- 
 tion is then called brazing; but a carbonate of the same 
 metal, viz. the dark grey or most fusible sort of pig iron 
 called No. 1, is the most durable solder that can be used. 
 The pig iron loses some brittleness, and the malleable 
 metal becomes harder in the proximity of the parts 
 soldered. 
 
 The parts upon which hard solder is intended to ope- 
 rate, are touched with a finely powdered borax moistened 
 wHh water. They must, also, as in all soldering and 
 tihning operations, be perfectly clean. The borax 
 quickly running into a kind of glass, promotes the fusion 
 of the solder, and preserves from oxidation the surfaces 
 to which it is applied. The pieces intended to be sol- 
 dered, are fastened together with iron wire, or secured 
 by some contrivance having the same effect. Speltre 
 being composed of so many grains, is apt to spread when 
 the borax boils up ; but just as it becomes fused, the 
 workmen bring it to the place where it is wanted, by a 
 slender iron rod. The flame of a lamp, directed by a 
 blow-pipe against the solder covering the intended joint, 
 which must be laid upon charcoal, is sufficient for small 
 things. For large work, a -common culinary fire may bo 
 made to effect the desired fusion, though a forge is still 
 more convenient. The fire should not touch the work, 
 nor the ashes be allowed if fall upon it. 
 
 The soft solders melt easily, but are partly brittle, 
 and therefore cannot be Hammered. The solder for lead 
 is usually composed of two parts of lead and one of tin. 
 Its goodness is tried by melting it, and pouring about the 
 size of a crown-piece upon a table ; little shining stars 
 will arise upon it, if it is good. By diminishing tta
 
 296 MECHANICAL EXERCISES. 
 
 proportion of lead, we form what is called stray solder j 
 we may also increase the proportion, which is advisable 
 when we wish to solder vessels for containing acids 
 because lead is not so easily corroded or dissolved as tin, 
 
 The lining of tea-chests has been used for solder, as it 
 sometimes comes mixed about the right proportion. 
 These valuable portions of tea-lead may be distinguished 
 by their brilliancy, having suffered little from oxidation ; 
 also, when they principally consist of tin, by the crack- 
 ing noise while bending; which is peculiar to this 
 metal, and some of the alloys into which it largely 
 enters. 
 
 The solder for tin may consist of four parts of pewter, 
 one of tin, and one of bismuth, or two parts of tin, and 
 one of lead : the latter is a composition much used. 
 
 The soldering-iron of the tin-plate workers is an ingot 
 of copper, flattened at the point, in a pyramidal form : 
 it is screwed or riveted to an iron stem fastened to a 
 wooden handle. The copper is seldom more than four 
 or five inches ,ong, and when it is worn away, the snrre 
 stem and handle are used for another piece. The bai 
 of copper is prepared for use, by filing it bright, and tin- 
 ning it ; when sufficiently hot, it will melt and take up 
 the solder, so as to afford a ready means of applying it 
 to the intended juncture. Powdered rosin, and some- 
 times pitch, is used along with the soft solders, to pre- 
 serve the metals employed from oxidation. 
 
 Tin-foil, applied between the joints of fine brass-work, 
 first wetted with a solution of sal ammoniac, and held 
 firmly together while heated, makes an excellent junc- 
 ture, care being taken to avoid too much heat. 
 
 OF GLUE. 
 
 To prepare glue, it must be steeped for a number of 
 hours, over night, for instance, in cold water, by which 
 means it will become considerably swelled and softened. 
 It must then be gently boiled, till it is entirely dissolved, 
 and of a consistence not too thick to be easily brushed 
 sver wood. About a quart of water may be used tp
 
 MECHANICAL EXERCISES. 297 
 
 half a pound of glue. The heat employed in melting 
 glue should not be more than is required to make watei 
 boil ; and to avoid burning it, the workmen, as is vveL' 
 known, suspend the vessel containing it in another vessel 
 containing only water, which latter vessel is made in the 
 form of a common tea-kettle without a spout, and alont 
 receives the direct action of the fire. 
 
 The circumstances most favourable to the best effect! 
 which glue can produce, in uniting two pieces of wood. 
 are the following: that the glue should be thoroughly 
 dissolved, and used boiling hot at the first or s* -.ond melt- 
 ing: that the wood should be warm and p' .fectly dry; 
 and a very thin covering of glue be inte posed at the 
 juncture, and that the surfaces to be united, be strongly 
 pressed together, and left in that state in a warm but 
 not hot situation, till the glue be completely hard. In 
 veneering, and for very delicate work, the whole of these 
 requisites, as they not only ensure the strongest, but the 
 j;lue sets the soonest, should be combined in the opera- 
 tion ; but on some occasions this is impossible, and, there- 
 fore, the most essential must be regarded, such as the 
 fitness of the glue, and dryness of the wood. When the 
 faces of joints, particularly those that cannot be much 
 compressed, have been besmeared with glue, which should 
 always be done with the greatest expedition, they should 
 be rubbed lengthwise one upon another, two or three 
 times, to settle them close. 
 
 When glue, by repeatedly heating it, has become of a 
 dark and almost black colour, its qualities are impaired ; 
 when newly melted, it is of a light ruddy brown colour, 
 nearly like that of the dry cake held up to the light ; 
 and while this colour remains, it may be considered fit 
 tor almost every purpose. Though glue which has been 
 melted is the most suitable for use, other circumstances 
 being the same, yet that which has been the longest 
 manufactured is the best. To try the goodness of glue, 
 steep a piece three or four days in cold water; if it 
 swell considerably without melting, and when taken out 
 resumes, in a short time, its former dryness, it is excel-
 
 298 MECHANICAL EXERCISES. 
 
 lent. If it be soluble in cold water, it is a proof that 
 it wants strength. 
 
 A glue which does not dissolve in water, may be ob- 
 tained by melting a common glue with the 'smallest 
 possible quantity of .water, and adding by degrees lin- 
 seed oil rendered drying by boiling it with litharge; 
 while the oil is added, the ingredients must be well stirred 
 to incorporate them thoroughly. 
 
 A glue which will resist water, in a considerable de- 
 gree, is made by dissolving common glue in skimmed 
 milk. 
 
 Finely lixiviated chalk added to the common solution 
 of glue in water, constitutes an addition that strengthens 
 it, and renders it suitable for boards, or other things 
 which must stand the weather. 
 
 A glue that will hold against fire or water, may be 
 prepared by mixing a handful of quick-lime with four 
 ounces of linseed oil : thoroughly lixiviate the mixture, 
 boil it to a good thickness, and then spread it on tin plates 
 in the shade; it will become exceedingly hard, but may 
 be dissolved over a fire, as ordinary glue, and is then fit 
 for use. 
 
 THE COMMON SLIDING RULE. 
 
 THE divisors inserted in the following table, and the 
 few plain directions and examples given, will now render 
 it capable of being applied to every purpose that any 
 artificer can possibly want. And by taking a copy of 
 the table upon a piece of'parchment, and carrying it 
 always in the pocket, these divisors will be at hand: and 
 the weight or measure required may be obtained. 
 
 Description of the lines upon the slide rule. 
 
 UPON the sliding rule of this rule are four lines mark- 
 ed A, B, C, and D. The three marked A, B, and C art 
 double lines of numbers, one of which is upon the rule, 
 and the other two are upon the slide. That marked JJ 
 is a single line of numbers, commonly called the girt line.
 
 MECHANICAL EXERCISES. 299 
 
 Numeration. 
 
 1 HESF four lines are divided as follows: each of the 
 double lines marked A, B, and C are figured 1, 2, 3, 4, 
 5, G, 7, 8, 9; then again 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 
 at the end. And these figures may be increased or de- 
 creased in the value, but always in a tenfold proportion, 
 at pleasure; thus one at the beginning may be called 
 either 1, or 10, or 100, or 1000, and then the one in the 
 middle of the rule must be called 10, 100, 1000 or 10,000. 
 Observe, from one to two is divided into 10 parts, and 
 each tenth is subdivided into 5 parts, and from 2 to 3 is 
 divided into ten parts, and each tenth into 2 parts, and 
 from 3 to 4 and so on to 10 is divided into 10 parts only 
 The girt line, marked D, is figured 4, 5, (>, 7, 8, 0, 10 
 12, 15, 20, 25, 30, 35, and 40 at the end. And tht 
 figures and divisors are valued in tenfold proportion, as 
 above. 
 
 As there have been so many books published for the 
 use of this RULE, it is unnecessary to say much upon the 
 subject; because when numeration is properly under- 
 stood, any person, from these plain directions, may per- 
 form any operation, in superficial and solid mensurations, 
 that may be wanted in the common course of business, 
 and, with the assistance of these divisors, may find the 
 weight of any of the articles contained in the table. 
 
 A TABLE OF DIVISORS 
 
 For the use of the common single Sliding Rule. 
 
 The first column contains the divisors for dimensions 
 that are taken feet long, feet wide, and feet thick. The 
 second column is for dimensions that are taken feet long, 
 inches wide and thick. The third column is for dimen- 
 sions that are taken inches long, inches wide, and inches 
 thick. 
 
 The fourth is a column of divisors for dimensions that
 
 300 MECHANICAL EXERCISES. 
 
 are taken feet long, and inches diameter. The fifth 
 column Is for dimensions that are taken inches long and 
 diameter. 
 
 The six.h is a column of divisors or diameters, taken in 
 feet. The seventh column is for diameters takeu in 
 inches. 
 
 
 Square. 
 
 Cylinders. 
 
 Globes. 
 
 1st 
 
 36 
 625 
 
 835 
 102 
 10 
 108 
 507 
 938 
 738 
 12 
 112 
 860 
 129 
 139 
 137 
 136 
 370 
 394 
 4!)5 
 795 
 108 
 94 
 963 
 151 
 
 2d. 
 
 518 
 9 
 12 
 147 
 144 
 1565 
 735 
 136 
 122 
 174 
 163 
 126 
 186 
 2 
 135 
 183 
 53 
 57 
 72 
 114 
 158 
 136 
 152 
 22 
 
 3d. 
 
 624 
 108 
 145 
 176 
 174 
 183 
 83 
 157 
 127 
 207 
 196' 
 152 
 222 
 241 
 235 
 22 
 637 
 69 
 860 
 138 
 190 
 164 
 169 
 [263 
 
 4th. 
 
 660 
 114 
 153 
 188 
 184 
 199 
 96 
 173 
 132 
 221 
 207 
 162 
 235 
 254 
 25 
 233 
 725 
 728 
 92 
 146 
 2 
 175 
 194 
 285 
 
 5th. 
 
 799 
 138 
 183 
 224 
 22 
 238 
 118 
 208 
 162 
 265 
 247 
 194 
 283 
 304 
 300 
 278 
 81 
 873 
 10 
 17G 
 237 
 208 
 214 
 236 
 
 6th. 
 
 625 
 119 
 16 
 196 
 191 
 207 
 939 
 173 
 141 
 23 
 214 
 169 
 247 
 265 
 261 
 239 
 72 
 755 
 95 
 151 
 208 
 18 
 186 
 287 
 
 7th 
 
 113 
 
 206 
 276 
 335 
 329 
 358 
 180 
 354 
 242 
 397 
 371 
 289 
 423 
 458 
 454 
 418 
 121 
 132 
 164 
 262 
 355 
 336 
 32 
 5t. 
 
 Cubic Feet . ... 
 
 Wine Gallons 
 
 
 Water in Ib 
 
 Oil in Ib . 
 
 G'Jdinlb 
 
 
 
 
 
 Lead Ib 
 
 
 Cast Iron and Speltre Ib. .... 
 Tin Ib 
 
 - Steel Ib . 
 
 Marble Ib 
 
 
 Brick Ib 
 
 Coal Ib 
 
 Dry Oak Ib 
 
 
 Box Ib y 
 
 Red Deal Ib .... 
 
 
 EXAMPLES. 
 
 EXAMPLE 1. Required the content in cubic inches of 
 piece of timber 2 feet long, 12 inches wide, and 1*4 
 inches thick ; see the preceding table of divisors in the 
 line of cubic inches, second column, and you will fina 
 the divisor for feet long, inches wide, and inches thick is 
 518, set 2, which is the length upon B, to 518, the divi-
 
 MECHANICAL EXERCISES. 301 
 
 sor upon A, against 12, which is the breadth and thickness 
 upon D, 345G, which is the content in inches on C. 
 
 Ex. 2 Having the dimensions of an unequal sided 
 piece of timber given to find the mean square, which 
 must be done in all cases where the breadth and thick- 
 ness are unequal. What is the square of a piece of 
 timber 16 inches broad, and four inches thick? Set 16, 
 the breadth on C, to 16 on D, and against 4, the thick- 
 ness on C is 8 inches the square on D. 
 
 Ex. 3. Required the content of a piece of cast iron 
 24 inches long and 12 square; see the preceding table 
 in the line cast iron and speltre, third column, is divisor 
 241 ; set 24 on B to 241 on A, and against 12 on D is 
 S96 on C. 
 
 Ex. 4. Required the weight of a piece of cast iron 
 circular 24 inches and 12 diameter: see the preceding 
 table, fifth column, in the line cast iron and speltre is 304 
 the divisor; set length on B to the divisor on A, and 
 against the diameter on D is 708 Ibs. the content on C. 
 
 Ex. 5. Required the weight of a ball or globe in cast 
 iron 12 inches in diameter; see the preceding table, 
 seventh column, in the line cast iron and speltre is 458, 
 the divisor; set 12 the diameter on B to 458, the divisor 
 on A, and against 12 inches diameter on D, is 235 the 
 content on C. 
 
 Ex. 6. Required the content of a piece of timber 1 
 inch long and 12 inches diameter ; see the preceding 
 table, in the line cubic inches, fifth column, under cylin- 
 ders, the divisor is 799 ; set 1 inch, the length on B, to 
 799 on A, and against 12 inches the diameter on D, is 
 113, the content on C. Observe, when the slide stands 
 in this position it is a table of areas of all circles, D being 
 diameters, or the squares of diameters, and C being areas 
 or superficial inches. 
 
 Ex. 7. Required the content of a piece of land, 70 
 yards long, by 70 wide ; set 4840 on A, the number of 
 yards in an acre, to 70 the length on B, and against 70 
 the width on A is 1.01 on B. 
 
 Ex. 8. Rquired the content of a piece of land, 40
 
 302 MECHANICAL EXERCISES. 
 
 poles long, and 5 poles wide; set 160, the number p5 
 poles in an acre on A, to 40 the length on B, and againsl 
 5, the width on A is 1.25 or 1 acre on B. 
 
 Ex. 9. Required the diameter of a circle, whose area 
 is equal an ellipsis or oval, 32 by 22 inches diameter 
 set 32 on C, to 32 on D, and against 22 on C is 20.6 
 nearly on D. 
 
 Ex. 10. Required the side of a square equal in pro- 
 portion to a parallelogram or long square, 32 by 22 
 inches; set 32 on C to 32 on D, and against 22 on C is 
 2C.6 the mean proportion on D. 
 
 Ex. 11. Required the content in roods of a piece of 
 walling, 25 feet long, and 10 feet high; set 63, which is 
 the number of feet in a rood on A, to 25 the length on 
 B, and against 10, the height on A is 4 roods nearly on B 
 
 Ex. 12. Required the content in roods of a piece of 
 walling, 876 feet long, and 5 feet high ; set 272^, which 
 is the area in feet of a rood on A, to 876 the length on 
 B, and against 5, the height on A are 16 roods nearly 
 on B. 
 
 CRANK 
 
 Ex. 14. Required the power of a crane handle suf- 
 ficient to balance a weight of 6000 Ibs. hung on a paii 
 of blocks 3 pulleys each, the wheel and roller bearing 
 such proportion as 2 is to 20 in diameter, and the handle 
 and pinion bearing such proportion as 1 is to 10 in radius. 
 Begin first with the weight and pulleys, and say if 6 pul- 
 icys give 6000 Ibs., 1 pulley or roller'will give 1000; or 
 set 6, the number of pulleys on B, to 6000, the number 
 of pounds on A, and against 1 roller on B is 1000 on A, 
 then say if 2, the inches diameter of the roller or axle 
 give 1000, the number of pounds being on it, or the 
 weight over the 6 pulleys, equal to 1000 Ibs. then 20 
 inches, the diameter of the wheel, will be equal to, <y 
 require 100 Ibs. to balance it. 
 
 OPERATION. Invert your slide and set 2 the diameter 
 of the roller on C to 1000, the number of pounds on A, 
 and against 20, the diameter of the wheel on C is 100 Ibs
 
 MECHANICAL EXERCISES. 303 
 
 to J'alance (he whole on A, then proceed with the ban- 
 vllf and pinion, and say if 1 inch, the radius of the han- 
 dle has 10 Ibs. to lift. 
 
 OPERATION. Set 1, the radius of the pinion on C to 
 .00, to the number of pounds to lift on A, and against 
 10, the radius of the handle on C is 10 Ibs. the iirst 
 power applied on A, th<: answer sought. 
 
 By this rule you may find any proportion of weight in 
 any number of movements of any unequal proportion in 
 any kind of mechanical powers, only observe where 
 more requires more, or less requires less, then your slide 
 must be the right way in, as usual, but when more re- 
 quires less, and less requires more, then your slide must 
 be inverted. 
 
 Ex. 15. Required the velocity in inches per minute of 
 the crane handle, while the weight 6000 Ibs. passes through 
 a space of 12.6 per minute. 
 
 OPERATION. Set 6000, the number of pounds on C to 
 12.6, the number of inches and parts that the weight 
 raises on A, and against 10 Ibs. the power applied on C 
 is 75, 600 inches, the velocity per minute on A the 
 answer. 
 
 Ex. 16. Lever. Suppose a lever with 672 Ibs. hung on 
 the short arm 1 foot from the fulcrum or prop, required 
 a weight to balance, hung at 6 feet from the fulcrum or 
 prop, on the long arm, as 1 is to 672, so is 6 to the num- 
 ber sought or answer; observe, it must be worked by 
 inverse proportion. 
 
 OPERATION. Invert your slide, and set 1 on C to 672 
 on A, and against 6 on C is 112 Ibs. the answer on A. 
 
 Ex. 17. Wheel and Jlxle. Required a weight hung on 
 the wheel 20 inches diameter to balance 100 Ibs. hung on 
 the axle 1 inch diameter 
 
 OPERATION. Invert your slide, set 1 on C to 100 on A, 
 and against 20 on C is 5. the content on A. 
 
 Ex. 18. Pulleys. Suppose 1000 Ibs. to be hung at a 
 pair of blocks, consisting of 10 pulleys, 5 loose, and 5 
 fast, or 5 in the upper and 5 in the lower block, what 
 weight should be hung at <.be last pulley to balance
 
 304 MECHANICAL EXERCISES. 
 
 them? direct proportion, say as 10 pulleys or ropes ac* 
 to 100 Ibs., so is 1 rope or pulley to 10 Ibs. the answer 
 Bought 
 
 OPERATION. Set 10 on B to 100 on A, and against 1 
 on B is 10 the content on A. 
 
 Ex. 19. Inclined Plane. Required a weight hung 
 on the perpendicular height being 12 inches to balance 
 75 Ibs. hung on the slant height, being 36 inches. Direc 
 proportion, say as 36, slant height is to 75 Ibs. so is 12 th 
 perpendicular height to the answer 25 Ibs. 
 
 OPERATION. Set 36 on B, to 75 on A, and against IV 
 on B, is 25 the answer on A. 
 
 Ex. 20. The Wedge. Required the power of a blow 
 struck on a wedge, whose half thickness 1 inch, and 
 length of one side 25 inches, and resistance 250 Ibs. 
 
 OPERATION. 25 on B, to 250 on A, and against 1 on 15 
 is 10, the answer on A. 
 
 Ex. 21. The Screw. Required the resistance or weight 
 lifted in pounds, the circumference of the screw being 
 20 inches, the power applied being 100 Ibs. and the dis 
 tance between two threads % of an inch. 
 
 OPERATION. Invert your slide, and set 100 on C, to 
 20 on A, and against 75, which is on f C, is 2650 the 
 content on A. 
 
 Ex. 22. The Engine Beam. Suppose the length of 
 the beam from the centre to be 6 feet long, and length 
 of stroke 4 feet long at the beam end, required the length 
 of stroke, the same beam is making at 1^, 3 feet and 4 
 feet from the centre, or any other length of stroke within 
 the same dimensions. 
 
 OPERATION. Set 4, the length of stroke on B to 6, the 
 length of the beam from the centre on A, and against 
 1}, 3 and 4^ feet on A is 1, 2, and 3 feet, the content on 
 B, or any other length that might be wanted within the 
 same dimension. 
 
 Ex. 23. Suppose the piston of a steam engine to travel 
 220 feet per minute, and the length of stroke up and 
 down to be 8 feet, what is the number of strokes per 
 minute.
 
 MECHANICAL EXERCISES. 305 
 
 OPERATION. Set 8 on B to 1 on unity on A, and against 
 220 on B is 271, the content on A. 
 
 Ex. 24. Suppose a piston to travel 220 feet per min- 
 ute, and the number of strokes to be 27^ per minute, 
 what is the length of one stroke up and down. 
 
 OPERATION. Set 27^ on A to 220 on B, against 1 on 
 A, being 8 feet, the length of stroke on B. 
 
 Ex. 25. Required, the number of feet a piston travels 
 m a minute, length of stroke being 8 feet, and numbei of 
 strokes being 27^. 
 
 OPERATION. Set 1 on A to 8 on B, and against 27^ en 
 A, is 220 on B. 
 
 Ex. 26. If a pendulum 39.2 inches long, make 60 vi- 
 brations per minute, what will one of 12 inches long 
 make. 
 
 OPERATION. Invert your slide, and set 39.2 on B to 60 
 on D, and against 12. on B, is 109, the content on D. 
 
 Ex. 27. Required, the number of feet a stone will fall 
 in 3 seconds, supposing it to fall 16 feet in the first 
 second. 
 
 OPERATION. Set 1 on D to 16 on C, and against 3 on 
 D, is 144 feet, the content on C. 
 
 Ex. 28. Required, the circumference of a wheel, the 
 diameter being 20 inches. 
 
 OPERATION. Set 1 on B to 3.14 on A, and against 20 
 on B, is 83, the content on A. 
 
 Ex. 29. Required, the diameter of a wheel, the cir- 
 cumference being 63 inches. 
 
 OPERATION. Set 3.14, which is the circumference of 
 1 inch on A, to 1, the diameter on B, and against 63, the 
 circumference on A is 20, the diameter on B. By this 
 rule, you find the pitch of all wheels nearly by setting- 
 the pitch of the cog on B to 3.14 on A, and against any 
 diameter on B, is the number of cogs on A, or against 
 any number of cogs on A, is the diameter on B. 
 
 Ex, 30. Suppose a drum upon one shaft 20 inches 
 diameter, to make 30 revolutions, which is turned by a 
 first drum ; then required the diameter of the last drum, 
 that makes 150 revolutions. 
 
 26* U
 
 306 MECHANICAL EXERCISES. 
 
 OPERATION. Invert your slide, and set 30, the revolu- 
 tions of the first drum on A to 20, the diameter of the 
 first drum in C, and against 150, the revolution of the 
 ast drum on A is 4 inches, the diameter of the last drum 
 on C. By this rule, you will find the revolution or diam- 
 eter of any different speed of any number of drums of an 
 unequal proportion ; for. as the revolutions on A are to 
 the diameter on C, so is the diameter to the revolutions 
 on A, or number sought. Observe, the slide must alvvay 
 be inverted in these operations. 
 
 Ex. 31. Tiling and Slating. Required the number 
 of Squares contained in a piece of tiling or slating 4,0 
 feet long by 15 wide. 
 
 OPERATION. Set 100 the number of feet in a square 
 on A to 40 the length on B, and against 15, the width on 
 A is 6, the content on B. 
 
 Ex. 32. Required the number of roods contained in 
 the above dimensions. 
 
 OPERATION. Set 63, the number of feet in a rood on 
 A to 40, the length on B, against 15 on A is 9^ roods 
 the content on B. 
 
 Ex. 33. Required the number of tiles sufficient to 
 cover the above dimensions. 
 
 OPERATION. Set 1 on A to 101^, the tiles in a rood 
 on B, and against 9^ the roods on A is 965, the number 
 of tiles required on B. 
 
 Ex. 34. Painters' Work. Required the number of 
 yards contained in a fence of 70 feet long, by 10^ feet 
 high. 
 
 OPERATION. Set 9, the number of feet in a yard on 
 A to 70 the length on B, and against 10 on A is 81f 
 the contents on B. 
 
 Ex. 35. Glaziers' Work. Required the number of 
 feet contained in a window 60 in. high, and 50 wide, 
 
 OPERATION. Set 144, the number of superficial inch- 
 es in a foot on A to 60, the length on B, and against 50, 
 the width on A is nearly 21.0 feet, the content on B, or 
 call it 5 feet high, and set 12 on A to 5 on B, and 
 against 50 on A is nearly 2LO feet, the same as above 
 on B
 
 MECHANICAL EXERCISES. 307 
 
 Ex. 3G Plasterers' Work. Required the number of 
 pards contained in a piece of plastering, 42 feet long by 
 SA feet high. 
 
 OPERATION. Set 9 on A to 12, the length on B, and 
 against 8^ feet high is 39f yards nearly on B. 
 
 Ex. 37. Pavers' Work. Required the number of 
 yards contained in a piece of paving 1G feet long by 
 13f wide. 
 
 OPERATION. Set 9 on A to 16J-, the length on B, an 
 against 13| on A, are 35 yards, the content on B. 
 
 Ex. 38. Required the number of bricks sufficient for 
 the above 25 yards, admitting the size of bricks to be 9 
 by 4^ inches, and a superficial yard to contain 32 ty-icks. 
 
 OPERATION. Set 1 on A to 32 on B, and against 25 on 
 A are 800 bricks, the content on B. 
 
 Ex. 39. Digging. Required the number of solid yards 
 contained in a piece of digging 15 feet long, 12 feet wide 
 and 2 feet deep; first find the mean proportion by setting 
 15 on D to 15 on C, and against 12 on C is 13, 45, the 
 square on D. 
 
 OPERATION. Set 9 the depth on B to 17, the common 
 divisor, on A, and against 13, 45 on D, are 60 yards, the 
 content on C. 
 
 Ex. 40. Timber Measure. Required the number of 
 cubic feet contained in a piece of timber 22 feet long, and 
 18 inches { girt. 
 
 OPERATION. Set 22, the length on B to 9 the common 
 divisor on A, and against the 5- girt on D are 49^ feet, 
 the content on C. 
 
 Ex. 41. Required the product of 2f inches, multi- 
 plied by 2f inches. 
 
 OPERATION. Set 1 on A to 2f on B, and against 2f or. 
 A is 7.G, the content on B. 
 
 Ex. 42. Required the number of Horse-power of 3 
 double powered Patent Steam Engine, the diameter of 
 the cylinder being 24 inches. 
 
 OPERATION. Set 5 on B to 9 on A, and against 24 on 
 D is 20 the content on C; observe, when the slide stands 
 here, it is a table of diameters and horses'-power, D being 
 a line of diameters, and C being a line of horses'-po'ver
 
 308 MECHANICAL EXERCISES. 
 
 Ex. 43. Required the side of 'a square in inches 
 iqual in area to a right angle triangle, whose base is 126 
 nches, and perpendicular height 94 inches. 
 
 OPERATION. Set 47. which is half the perpendicular 
 jn C to 47 the same on D, and against 126 on C is 76.9 
 the content on D; observe, taking half the perpendicular 
 is the common rule in all triangles to find the area. 
 
 Ex. 44. Required the side of a square in feet, equal 
 in area to a common triangle, whose base is 48 feet, and 
 perpendicular height 24 feet. 
 
 OPERATION. Set 12, which is half the perpendicular 
 on C to 12 the same on D, and against 48 on C is 24, the 
 answer on D. 
 
 Ex. 45. Required, the weight of a hay-stack, admit- 
 ting 1 solid yard, or 27 solid feet, to 1 cwt. 1 qr. lb M 
 and the stack to measure 30 feet long, 12 feet wide, and 
 10 feet high, up to the hips, or eaves. In this case, it will 
 be necessary to take the length and width about 5 feet 
 high, that is, about the middle, calling this the mean 
 proportion, which will be sufficiently true in cases of 
 this kind. 
 
 OPERATION. The first thing is to find the square of it, 
 which is necessary, in all unequal dimensions, before the 
 question can be stated : this is found by setting 30, the 
 feet long, on 30, the same on D, and against 12, the feet 
 wide on C, are 19, the feet square on D nearly, then set 
 10, the feet high on B, to this common number or divisor, 
 136 on A, and against 19, the feet square on D, is 161 
 cwt. qr. lb., the content on C. 
 
 Ex. 46. Required, the content of the top of the stack 
 (that is, that part above the hips or eaves, which con- 
 tains the roof, &c.,) its length being 30 feet, width being 
 12, and perpendicular height being 10 feet. 
 . OPERATION. Set 5, which is half the perpendicular on 
 B, that is, the depth to that common number or divisor 
 136, as above, and against 19, the square on D, as in ex 
 ample above, is 83 cwt 1 qr., the content on C. Now 
 the uody of the stack being 167 cwt. qr. lb., which 
 being added to 83 cwt. 1 qr. lb., makes the whole 950 
 cwt 1 qr., the answer.
 
 MECHANICS. 
 
 THE science of mechanics has been very concisely de- 
 fined the geometry of motion. It is divided, by Sir Isaac 
 Newton, into the two branches of practical and rational 
 mechanics. Practical mechanics treat of the six mechani- 
 cal powers, of one or more of which every machine is 
 composed ; and rational mechanics comprehends the 
 whole theory of motion, shows how to determine the mo- 
 tions produced by given powers or forces, and, conversely, 
 when the phenomena of the motions are given, how to 
 trace the power of forces from which they arise. 
 
 To enter into a full detail of mechanics, would swell 
 this volume beyond its intended limits; and, having 
 dwelt somewhat at large on mechanical exercises, under 
 this head, we shall only add an Abstract of Mechanics. 
 
 ABSTRACT OF MECHANICS. 
 
 OF MATTER. 
 
 1. EVERY portion of matter is possessed of the follow- 
 ing properties, viz. solidity, extension, divisibility, mobility, 
 inertia, attraction, and repulsion. 
 
 2. Solidity is that property by which two bodies can- 
 not occupy the same place at the same time. It is some- 
 times called the impenetrability of matter. 
 
 3. The extension, like the solidity of matter, is proved 
 by the impossibility of two bodies co-existing in the same 
 place. 
 
 4. Divisibility is that property by which bodies are 
 capable of being divided into parts removeable from each 
 other. 
 
 5. Mobility expresses the capacity of matter to be 
 moved from one position or part of space to anofher
 
 310 ABSTRACT OF MECHANICS. 
 
 6. Inertia is the term which designates the passive ness 
 of matter, which, if at rest, will for ever remain in that 
 state, until compelled by some cause to move ; and, on 
 the contrary, if in motion, that motion will not -cease, or 
 abate, or change its direction, unless the body be resisted 
 
 SPACE. 
 
 1. SPACE is either absolute or relative. 
 
 2. Absolute space is merely extension, illimitable, im- 
 moveable, and without parts; yet, for the convenience 
 of language, it is usually spoken of as if it had parts. 
 Hence the expression, 
 
 3. Relative space, which signifies that part of absolute 
 space which is occupied by any body, as compared with 
 any part occupied by another body. 
 
 ATTRACTION. 
 
 1. ATTRACTION denotes the property which bodies have 
 to approach each other. 
 
 2. There are five kinds of attraction, the attraction 
 of cohesion, of gravitation, of electricity, of magnetism, 
 and chemical attraction. 
 
 3. The attraction of cohesion is exerted only at very 
 small distances. 
 
 4. The strength of the attraction of cohesion being 
 different in different kinds of matter, is supposed to be 
 the cause of the relative degrees of hardness of different 
 bodies. 
 
 5. Capillary attraction is only a particular modification 
 or branch of the attraction of cohesion. 
 
 6. The attraction of gravitation is exerted by every 
 particle of matter on every other particle at all distances, 
 but by no means with equal intensity at all distances. 
 
 7. Gravitation decreases from the surface of the earth 
 upwards as the square of the distance increases ; but 
 from the surface of the earth downwards, it decreases 
 only in a direct ratio to the distance from the centre.
 
 \BSTRACT OF MECHANICS. 3^1 
 
 REPULSION. 
 
 1. REPULSION' is that property in bodies, whereby, if 
 Ihey are placed just beyond the sphere of each other's 
 attraction of cohesion, they mutually fly from each other 
 
 2. Oil refuses to mix with water, from the repulsion 
 between the particles of the two substances ; and from 
 the same cause, a needle gently laid upon water will swim. 
 
 MOTION. 
 
 1. Absolute motion is the actual motion that bodies 
 have, considered indepem- ntly of each other, and only 
 with regard to the parts o space. 
 
 2. Relative motion is ti degree and direction of the 
 motion of one body, when >m pared with that of another. 
 
 3. decelerated motion i when the velocity continually 
 increases. 
 
 4. Retarded motion is when the velocity continually 
 decreases ; and the motion is said to be uniformly re- 
 tarded, when it decreases equally in equal times. 
 
 5. The velocity of uniform motion is estimated by the 
 time employed in moving over a certain space ; or, which 
 amounts to the same thing, by the space moved over in a 
 certain time. 
 
 6. To ascertain the velocity, divide the space run over 
 by the time. 
 
 7. To ascertain the space run over, multiply the veloci- 
 ty by the time. 
 
 8. In accelerated motion, the space run over is as the 
 square of the time, instead of being directly as the time, 
 as in uniform motion. 
 
 9. A body acted upon by only one force, will always 
 move in a straight line. 
 
 10. Bodies acted upon by two single impulses, whether 
 equal or unequal, will also describe a right line. 
 
 11. But when a body is acted upon by one uniform 
 force, or single impulse, and another accelerated or re- 
 tarded lorce, the two forces will cause it to describe a
 
 312 \BSTRACT OF MECHANICS. 
 
 12. The curve described by a body projected from the 
 earth, and drawn down by the action of gravity, would 
 in an unresisting medium, be that of a parabola ; bu 
 from the resistance of the air, which, when the velocity 
 is very great, will often amount to one hundred times 
 the weight of the projectile, the curve really described 
 approaches more nearly to that of a hyperbola. 
 
 13. The momentum of a body is the force with which 
 it moves, and is in proportion to the weight, or quantity 
 of matter, multiplied into its velocity. 
 
 14. The actions of bodies on each other are always 
 equal, and exert in opposite directions ; so that any body 
 acting upon another, loses as much force as it commu 
 nicates. 
 
 CENTRAL FORCES. 
 
 1. THE central forces are the centrifugal and the 
 centripetal forces. 
 
 2. The centrifugal force is the tendency which bodies 
 that revolve round a centre, have to fly from it in a 
 tangent to the curve they move in, as a stone from a 
 sling. 
 
 The centripetal force is that which prevents a body 
 from flying off, by impelling it towards the centre, as the 
 attraction of gravitation. 
 
 CENTRE OF GRAVITY. 
 
 1. THE centre of gravity is that point in a body about 
 which all its parts exactly balance each other in every 
 position. 
 
 2. A vertical line passing through the centre of gra- 
 vity of a body, is called the line of direction. 
 
 3. When the line of direction falls within the base of 
 a body, that body cannot descend ; but if it falls without 
 the base, the body will fall. 
 
 THE LEVER. 
 
 1. THERE are three kinds of levers, the difference 
 between which is constituted by the difference in the
 
 ABSTRACT OF MECHANICS. 313 
 
 situation of the fulcrum, and the power with respect tn 
 each other. In the first kind of lever, the fulcrum is 
 placed between the power and the weight. In the second 
 kind of lever, the fulcrum is at one end, the power at 
 the other, and the weight between them. In the third 
 kind of lever, the power is applied between the fulcrum 
 and the weight. 
 
 2. In all these levers, the power is to the weight, as 
 the distance of the weight from the fulcrum is to tha 
 of the power from the fulcrum. 
 
 3. A bent or hammer lever., differs only in the form 
 from a lever of the first kind. 
 
 4. Scissors, pincers, snuffers, and the common iron 
 screw, are all levers of the first kind. 
 
 5. The strutvra or Roman steel-yard, is a lever of the 
 first kind, with a moveable weight 
 
 6. A balance is also a lever of the first kind with 
 equal arms ; a perfect balance should combine the fol- 
 lowing requisites. I. The arms of the beam should be 
 exactly equal, both ;is to weight and length, and should 
 at the same time be as long as possible, relatively to 
 their thickness. 2. The points from which the scales are 
 suspended, should be in a right line, passing through the 
 centre of gravity of the beam. 3. The fulcrum ought 
 to be a little higher than the centre of gravity. 4. The 
 axis of motion should be formed with an edge like a 
 knife, and, with the rings and other bearing parts, should 
 be very hard and smooth. 5. The pivots, which form 
 the axis of motion, should be in a straight line, and at 
 right angles to the beam. 
 
 7. The best balances are not calculated to determine 
 weights with certainty to more than five places of 
 figures. 
 
 8. The oars and rudders of vessels are levers of the 
 second order ; a pair of bellows, nut-crackers, &c. are 
 composed of two levers of the same kind. 
 
 9. The third kind of lever is used as little as possible, 
 on account of the disadvantage to the moving power, the 
 intensity of which must always exceed the resistance 
 
 27
 
 314 ABSTRACT OF MECHANICS. 
 
 yet in some cases this disadvantage is over-balanced by 
 the quickness of its operations, and the small compass in 
 which it is exerted ; hence its fitness for the bones of the 
 arm, arid the limbs of animals generally. 
 
 10. In compound levers, the power is to the weight, in 
 a ratio compounded of the several ratios which these 
 powers that can sustain the weight by the half of each 
 lever, when used singly and apart from the rest, have to 
 the weight. 
 
 THE PULLEY. 
 
 1 PULLEYS are of two kinds, fixed and moveable. 
 
 2. The fixed pulley only turns upon its axis, and affords 
 no mechanical advantage; therefore, when the powei 
 and the weight are equal, they balance each other. It 
 is used for the convenience of changing the direction of a 
 motion. 
 
 3. The moveable pulley not only turns upon its axis, bu* 
 rises and falls with the weight. 
 
 4. Every moveable pulley may be considered as hang 
 ing by two ropes equally stretched, and wi.ich, conse> 
 quently, being equal portions of the weight, therefore 
 each pulley of this sort doubles the power. 
 
 5. A pulley of one spiral groove upon a truncated cone 
 as the fusee of a watch, is calculated to maintain a con- 
 stant equilibrium or relation between two powers, the 
 relative forces of which are continually changing. 
 
 WHEEL AND AXLE. 
 
 1. TKE power must be to the weight, in order to pro- 
 duce an equilibrium, as the circumference of the wheel is 
 to the circumference of the axle. 
 
 2. As the diameters of different circles bear the same 
 proportion to each other that their respective circum- 
 ferences do, the power is also to the weight as the diam- 
 eter of the wheel, to the diameter of the axle. 
 
 3. If one wheel move another of equal circumference 
 no power will be gained, as they will both move equalli 
 fast.
 
 ABSTRACT OF MECHANICS. 3l5 
 
 4. But if one wheel move another of different diame- 
 ter, whether larger or smaller, the velocities with which 
 they move will be inversely as their diameters, circum- 
 ferences, or number of teeth. 
 
 5. The wheel and axle may be considered as a per- 
 petual lever, from the constant renewal of the points of 
 suspension and resistance. The fulcrum is the centre of 
 the axis, the longer arm is the radius of the wheel, and 
 the shorter arm the radius of the axis. 
 
 G. The crane, and many other machines, of the first 
 consequence, are composed principally of the wheel and 
 axle. 
 
 THE INCLINED PLANE. 
 
 1. THE power and the weight balance each other, 
 when the former is to the latter as the height of the 
 plane to its length. 
 
 2. In estimating the draught of a wagon, or other 
 vehicle, up-hill, the draught on the level must be added; 
 so that, if the hill rises one foot in four, one fourth part 
 of the weight must be added to the draught on level 
 ground. 
 
 THE WEDGE. 
 
 1. WHEN the resistance acts perpendicularly to the 
 sides, that is, when the wedge does not cleave at any 
 distance, there is an equilibrium between the resistance 
 and the power, when the latter is to the former as half 
 the thickness of the back of the wedge is to the length 
 of one of its sides. 
 
 2. When the resistance on each side acts parallel to 
 the back, that is, when the wedge cleaves at some dis- 
 tance, the power is to the resistance as the whole icngth 
 of the back to double its perpendicular height. 
 
 3. The thinner the wedge, the greater its power. 
 
 4. The further a wedge is driven into, any material, 
 the greater also is its power, the sides of the cleft aiFord- 
 ing it the advantage of operating upon two levers. 
 
 5. Axes, spades, chisels, knives, and all instruments
 
 316 ABSTRACT OF MECHANICS. 
 
 which begin with edges or points, and grow gradually 
 thicker, act on the principle of the wedge. 
 
 THE SCREW. 
 
 1. THE screw is an inclined plane encompassing the 
 cylinder. 
 
 2. It is generally used with a lever ; and the power is 
 to the weight, as the distance from one thread or spiral 
 to another is to the circumference of the circle described 
 by the power. 
 
 3. The friction of the screw is very great, a circum- 
 stance that occasions this machine to sustain a weight or 
 press upon a body, after the power by which it was 
 impelled is removed. -> 
 
 4. A screw cut on an axle to serve as a pinion, is 
 called an endless screw. 
 
 5. The endless screw is very useful, either in converting 
 a very rapid motion into a slow one, or vice versa, as for 
 each of its revolutions the wheel moves but one-tenth. 
 
 COMPOUND MACHINES. 
 
 1. IN all machines, simple as well as compound, what 
 is gained in power is lost in time ; but the loss of time is 
 compensated by convenience. 
 
 2. The mechanical power of an engine may be known 
 by measuring the space described in the same time by 
 the power and the resistance or weight ; or by multiply- 
 ing into each other the several proportions subsisting 
 between the power and the weight, in every simple me- 
 chanical power of which it is composed. 
 
 3. The power of a machine is not altered by varying 
 the S:LO of the wheels, provided the proportion produced 
 by the multiplication of the power of the several parts 
 remains the same. 
 
 4. In constructing machines, simplicity of parts and 
 uniformity of motion should be particularly studied. 
 
 5. The teeth of wheels should always be made as 
 numerous as possible ; and when great strength is re- 
 quired, it should be obtained by increasing the width or 
 thickness of the wheel.
 
 ABSTRACT OF MECHANICS. 3 1 1 
 
 6. The use of the crank is one of the best modes of 
 converting a reciprocating into a rotatory motion, and 
 vice versa. 
 
 FLY-WHEELS. 
 
 1. A fly-wheel is a reservoir of power, and is employed 
 to equalize the motion of a machine. 
 
 2. This equalization of the motion is the only source 
 of the advantage of a fly, which can impart no power it 
 has not received. 
 
 3. When a fly is used merely as a regulator, it should 
 be near the first mover ; if intended to accumulate force 
 in the working point, it should not be separated far from 
 that point. 
 
 FRICTION. 
 
 1. FRICTION is occasioned by the roughness and cohe- 
 sion of bodies. 
 
 2. It is in general equal to between one-half and one- 
 fourth of the weight or force with which bodies are 
 pressed together. 
 
 3. It is increased in a small degree by an increase of 
 the surfaces in contact. 
 
 4. It is increased to an extraordinary degree, by pro- 
 longing the time of contact. 
 
 5. Two metals of the same kind have more friction 
 than two different metals. 
 
 6. Steel and brass are the two metals which have the 
 least friction upon each other. 
 
 7. The general rule for lessening friction consists in 
 substituting the rolling for the sliding motion. 
 
 MEN AND HORSES, CONSIDERED AS FIRST 
 MOVERS. 
 
 1. Lv turning a wrench, a man exerts his strength in 
 different proportions at different parts of the circle. The 
 force is, when he pulls the handle up from the height of 
 tiis knee ; and the least when he thrusts from him hori- 
 zontally. 
 
 '27*
 
 318 ABSTRACT OF MECHANICS. 
 
 2. When two handles are used to an axle, one at each 
 extremity, they should be fixed at right angles to each 
 other. 
 
 3. The art of Cc. Tying large burdens, consists in keep 
 ing the column of the body as directly under the weight 
 and as upright as possible. 
 
 4. The horse exerts his force to the greatest advan 
 tage in drawing or carrying up a hill. 
 
 5. The force with which a horse works, is compounded 
 of his weight and muscular strength. 
 
 6. The walk of a horse working in a mill should never 
 be less than forty feet in diameter. 
 
 7. A horse exerts most strength when drawing upon a 
 plane. 
 
 MILL-WORK. 
 
 1. WATER-WHEELS are of three kinds; viz. undershot- 
 wheels, breast-wheels, and overshot-wheels. The powers 
 necessary to produce the same effect on each of these 
 must be to each as the numbers 2.4, 1.75, and 1. 
 
 2. The undershot-wheel is used only when a fill-water 
 cannot be obtained. 
 
 3. A water-wheel twice as broad as another has more 
 than double the force. 
 
 4. An axis, furnished with a very oblique spiral, and 
 placed in the direction of a stream, may be rendered a 
 powerful first-mover, adapted to a deep and slow current 
 
 5. A mill-stone should make 120 revolutions in a 
 minute. 
 
 6. Bevclled-wheels are much used for changing the 
 direction of motion in wheel work. 
 
 7. Hooke's universal joint is sometimes used with ad 
 vantage for the same purpose. 
 
 8. The teeth of wheels should never, if it can be 
 avoided, act upon each other before they arrive at the 
 line joining the centres. 
 
 9. To ensure a uniformity of pressure and velocity in 
 the action of one wheel upon another, the teeth should 
 be formed into epicycloides, or into involutes, of the cir-
 
 ABSTRACT OF MECHANICS. 319 
 
 cumferences of the respective wheels ; or if the teeth of 
 one wheel be either circular or triangular, the teeth of 
 he same wheel should have a figure compounded of an 
 epicycloid, and that of the figure of the first wheel. 
 
 10. The object of thus forming the teeth is, that they 
 may not slide, but roll upon each other ; by which means, 
 the friction is almost annihilated. 
 
 11. It is a great improvement in machinery, where 
 trundles are employed with cylindrical staves, to make 
 these staves moveable on their axis. * 
 
 12. A heavy mill-stone requires very little more power 
 than a light one ; but it performs much more work, and 
 more effectually equalizes the motion, like a heavy fly. 
 
 13. The corn as it is ground, is thrown out between 
 the mill-stones, by the centrifugal force it has acquired. 
 
 14. The manual labour of putting the ground corn into 
 sacks, in order to raise it to the top of a mill-house, may 
 be obviated by the use of a chain of buckets wrought 
 by machinery. 
 
 WHEEL CARRIAGES. 
 
 1. A HORSE draws with the greatest advantage, when 
 the line of traction or draught is inclined upwards, so as 
 to make an angle of about 15 degrees with the horizon- 
 tal plane. 
 
 2. By this inclination, the line of traction is set at 
 right angles to the shape of the horses' shoulders, all 
 parts of which are, therefore, equally pressed by the 
 collar. 
 
 3. Single horses are preferable to teams, because in a 
 team, all but the shaft horse draw horizontally, and con- 
 sequently to disadvantage. 
 
 4. A horse, when part of the weight presses on his 
 back, will draw a weight to which he would otherwise 
 be incompetent. 
 
 5. The fore-wheels of carriages are less than the hind 
 wheels, for the convenience ogf turning in a smaller com- 
 pass. 
 
 6. In ascending, high wheels facilitate the draught, ic
 
 320 ABSTRACT OF MECHANICS. 
 
 proportion to the squares of their diameters; but in 
 descending, they press in the same proportion. 
 
 7. In descending, the body of a cart may be advan- 
 tageously thrown backwards, so that the bottom of it 
 will be horizontal, while the shafts incline downwards. 
 
 8. In loading four-wheeled carriages, the greatest 
 weight should be laid upon the large wheels. 
 
 9. Dished wheels are better calculated than any other 
 to sustain the jolts and unavoidable inequalities of pres- 
 sure arising from the roughness of roads. 
 
 10. The extremities of the axles should be in the same 
 horizontal plane, and the wheels should be placed on 
 them at right angles. 
 
 11. Broad cylindrical wheels smooth and harden a 
 road, while narrow ones cut it into furrows, and conical 
 ones grind the hardest stones to powder. 
 
 CLOCK-WORK. 
 
 1. To ascertain the number of revolutions which a 
 pinion makes, for one of the wheels working in it, divide 
 the number of its leaves by the number of teeth of the 
 wheel, and the answer is obtained. 
 
 2. By increasing the number of teeth in the wheels ; 
 by diminishing the number of leaves in the pinions ; by 
 increasing the length of the cord that suspends the 
 weight ; and lastly, by adding to the number of wheels 
 and pinions, a clock may be made to go any length of 
 time, as a month, or a year, without winding up. 
 
 3. The inconvenience of taking up more room, imt 
 principally the increase of friction which would be in 
 Iroduced, are the causes of its being inexpedient to 
 make a clock go beyond eight days. 
 
 4. Clocks intended to keep exact time, are contrived 
 to go whilst winding up. 
 
 5. Clocks which have pendulums vibrating half se 
 conds, are frequently moved by a spring instead of a 
 weight. 
 
 6. A spring is strongest when it is first wound up, anJ 
 rjrad-ially decreases in strength till the movement stops
 
 ABSTRACT OF MECHANICS. 321 
 
 it is therefore contrived to draw the chain over a conical 
 barrel, so that the lever at which it pulls is lengthened 
 as it grows weaker, by which means its effects are 
 equalized. 
 
 7. The plates of clock-makers' engines may be quick- 
 ly divided into odd numbers, by subtracting from the odd 
 number so much as will leave an even number of easy 
 subdivision ; then calculating the number of degrees con- 
 tained in the parts subtracted, and setting them off on 
 the circumference of the circle from a sector. 
 
 8. The geometrical radius of wheels, when the teeth 
 are epicycloidal, is less than the acting diameter, by 
 about f ths of the breadth of a teeth or measure. 
 
 9. The relative size of a pinion must be less for a 
 small wheel than for a large one, and also smaller when 
 driven than when it is the driver. 
 
 PENDULUMS. 
 
 1. ALL vibrations of the same pendulum, whether 
 great or small, if cycloidal, are performed in equal times. 
 
 2. The longer a pendulum, the slower are its vibra- 
 tions. 
 
 3. A pendulum to vibrate seconds, must be shorter at 
 the equator than at the poles. 
 
 4. Heat lengthens and cold shortens pendulums. 
 
 5. The quicksilver pendulum, the gridiron pendulum, 
 and many others, have been contrived to obviate these 
 effects of the change of temperature. 
 
 6. The vibrations of pendulums are affected by differ- 
 ences in the density of the medium in which they are 
 performed. 
 
 7. The merit of the only contrivance to remedy this 
 defect is due to Rittenhouse. It consists in the use of 
 two pendulums, one of which is very light, and placed 
 in an inverted position, extending above the point of sus- 
 pension of the other. 
 
 8. This compound pendulum may be made to vibrate 
 quicker in so dense a medium as water than in the open 
 air 
 
 V
 
 SANBORN & GARTER'S PATENT MACHINE 
 
 BOOKS.
 
 GENERAL AND MOST USEFUL SELECTION 
 
 OF 
 
 RECEIPTS: 
 
 WHICH WILL PROVE OF THE GREATEST UTILITY 
 TO 
 
 THE ARTIST, THE MECHANIC, 
 THE FARMER, AND THE LABOURING MAN. 
 
 EMBRACING 
 
 THE WHOLE COURSE OF THE ARTS, 
 
 Selecting and reducing such parts as ere often wanted, when the employment 
 
 of tlw professors of such business would be too expensive arid enibar 
 
 rassing. The aid of which will enable also the experimenter 
 
 impelled by genius to perform and invent with greater 
 
 ease and success, in some cases; while in others 
 
 obstacles will be removed that otherwise 
 
 would be insurmountable. 

 
 MISCELLANEOUS RECEIPTS. 
 
 Method for making Black Writing-ink. 
 
 \\ six quarts of water, boil four ounces of logwood IB 
 chips, cut very thin across the grain. The boiling may 
 be continued for nearly an hour, adding, from time to 
 time, a little boiling water, to compensate the waste by 
 evaporation. Strain the liquor while hot, suffer it to 
 cool, and make up the quantity equal to five quarts, by 
 the further addition of cold water. To this decoction, put 
 
 1 Ib. avoirdupois of blue galls, coarsely bruised; or 
 20 oz. of the best galls, in sorts. 
 4 oz. of sulphate of iron, calcined to whiteness. 
 ^ oz. of acetate of copper, previously mixed with the 
 
 decoction till it forms a smooth paste. 
 3 oz. of coarse sugar, and 
 6 oz. of gum-Senegal or Arabic. 
 
 These several ingredients may be introduced one after 
 another, contrary to the advice of some, who recommend 
 the gum, &c. to be added when the ink is nearly made. 
 The composition produces the ink usually called Japan 
 Ink, from the high gloss which it exhibits when written 
 with ; and a small phial of it has been sold for 12 cents. 
 
 The above ink, though possessing the full proportion 
 of every ingredient known to contribute to the perfection 
 of ink, will not cost more, to those who prepare it for 
 themselves, than the commonest ink which can be bought 
 by retail. The receipt was given to the public by De- 
 sormeaux. It answers for copying letters, by transferring 
 from them an impression to a damp sheet of thin, unsized 
 paper, passing through a small rolling-press. 
 
 When gurn is very dear, or when no very high gloss 
 28 (**>
 
 3?6 MISCELLANEOUS RECEIPTS. 
 
 is required, four ounces will be sufficient, with one ounce 
 and a-half of sugar. 
 
 By using only 12 oz. of galls to 4 oz. of sulphate of iron, 
 uncalcined, omitting the logwood, and acetate of copper 
 and the sugar, and using only 3 oz. of gum, a good and 
 cheap common ink will be obtained. 
 
 Lamp-black has been added to ink, to prevent its col- 
 our from being destroyed by the action of the oxy mu- 
 ialic acid. It should be burnt in a closed crucible, to 
 ender it less oily. It causes the ink to write much 
 less freely, although it may be useful for particular oc 
 casions. 
 
 Red-Ink for Writing. 
 
 BOIL over a slow fire, 4 oz. of Brazil-wood, in small 
 raspings or chips, in a quart of water, till a third part of 
 the water is evaporated. Add during the boiling, two 
 drams of alum in powder. When the ink is cold, steam 
 it through a fine cloth. Vinegar or stale urine is often 
 used instead of water. In case of using water, I pre- 
 sume a very small quantity of sal-ammoniac would im- 
 prove this ink. 
 
 Blue-Ink. 
 
 TAKE Sulphate of Indigo, dilute it with water till It 
 produces the colour required. It is with sulphate very 
 largely diluted, that the faint blue lines of ledgers and 
 other account books are ruled. If the ink were used 
 strong, it would be necessary to add chalk to it, to neu- 
 tralize the acid. The sulphate of indigo may be had of 
 the woollen dyers. 
 
 Fire and Water-proof Cement. 
 
 To half a pint of milk, put an equal quantity of vine- 
 gar, in order to curdle it ; then separate the curd from 
 the whey, *nd mix the whey with four or five eggs, 
 beating the whole well together. When it is well mixed, 
 add a little quicklime through a sieve, until it has ac- 
 quired the consistence of a thick paste. With this
 
 MISCELLANEOUS RECEIPTS. 327 
 
 cement, broken vessels and cracks of all kinds may be 
 mended. It dries quickly, and resists the action of water 
 as well as of a considerable degree of fire. 
 
 A Cement for stopping the Fissures of Iron Vessels. 
 
 TAKE two ounces of muriate of ammonia, one ounc 
 'of flowers of sulphur, and sixteen ounces of cast-iron 
 filings or turnings; mix them well in a mortar, and keep 
 the powder dry. When the cement is wanted, take one 
 part of this and twenty parts of clean iron filings or 
 borings, grind them together in a mortar, mix them with 
 water to a proper consistence, and apply them between 
 the joints. 
 
 This answers for flanges of pipes, &c. about steam 
 engines. 
 
 Lutes. 
 
 LUTES are compositions which are employed to defend 
 glass and other vessels from the action of fire, or to fill 
 up the vacancies which occur, when separate tubes, foi 
 the necks of different vessels, are inserted into each other 
 during the process of distillation. Those lutes which 
 are exposed to the action of fire, are usually called fire 
 lutes. 
 
 For a very excellent fire-lute, which will enable glass 
 vessels to sustain an incredible degree of heat, take frag- 
 ments of porcelain, pulverize and sift them well, and add 
 an equal quantity of fine clay, previously softened with 
 as much of a saturated solution of muriate of soda, 
 as is requisite to give the whole a proper consistence. 
 Apply a thin and uniform coat of this composition to the 
 glass vessels, and allow it to dry slowly before they are 
 put into the fire. 
 
 Equal parts of coarse and refractory clay mixed with 
 a little hair, form a good lute. 
 
 Fat earth, beaten up with fresh horse-dung, Chaptal 
 recommends as an excellent fire-lute, which he generally 
 used, and the adhesion of which was such, that after the 
 retort had cracked, the distillation rm-.W ^ carried on 
 and regularly finished.
 
 328 MISCELLANEOUS RECEIPTS. 
 
 Lutes for the joining of such vessels "as retorts and re 
 ceivers, are varied according to the nnture of the vapours 
 which will act against them, in order not to employ a 
 more expensive and troublesome composition than the 
 case requires. For resisting watery vapours, slips of wet 
 bladder, or slips of wet paper or linen, -covered with still 
 flour paste, may be bound over the juncture. 
 
 A closer and neater lute for more penetrating vapours 
 B composed of whites of eggs made into a smooth paste 
 with quick-lime, and applied upon strips of linen. The 
 quick-lime should be previously slacked in the air, and 
 reduced to a fine powder. The cement should be ap- 
 plied the moment it is made ; it soon dries, becomes very 
 firm ; and is in chemical experiments one of the most 
 useful cements known. 
 
 Where saline, acrid vapours are to be resisted, a 
 lute should be composed of boiled linseed oil intimately 
 mixed with clay, which has been previously dried, finely 
 powdered, and sifted. This is called fat lute. It is ap- 
 plied to the junctures, as the undermost layers, and is 
 secured in its place by the white of egg-lute last mention- 
 ed, which is tied ou with pack-thread. 
 
 Blacking, to make. 
 
 PUT 1 gallon of vinegar into a stone jug, add 1 Ib. of 
 Jvory-black, well pulverized, ^ a Ib. of loaf sugar, ^ an 
 oz. of oil of vitriol, and 1 oz. of sweet oil ; incorporate the 
 whole by stirring. 
 
 This is a blacking of very great repute in different 
 countries, and on which great praise has been very de- 
 servedly bestowed. It has decidedly been ascertained, 
 from experience, to be less injurious to the leather, than 
 most public blackings; and it certainly produces a fine 
 jet polish, which is rarely equalled, and never jet sur
 
 1LISCELLANEOUS RECEIPTS. 329 
 
 TARNISHES. 
 
 To dissolve Copal in Mcohol. 
 
 COPAL, which is called gum copal, but which is not, 
 strictly, either a gum or a resin, is the hardest and least 
 changeable of all substances adapted to form varnishes, 
 by their dissolution in spirit, or essential, or fat oils. It, 
 therefore, forms the most valuable varnishes ; though we 
 shall give several receipts where it is not employed, 
 which form cheaper varnishes, sufficiently good for many 
 purposes, adding only the general rule, that no varnish 
 must be expected to be harder than the substance from 
 which it is made. 
 
 To dissolve copal in alcohol, dissolve half an ounce of 
 camphor in a pint of alcohol; put it into a circulating 
 glass, and add 4 oz. of copal in small pieces; set it in a 
 sand-heat, so regulated that the bubbles may be counted 
 as they rise from the bottom, and continue the same heat 
 till the solution is completed. 
 
 The process above-mentioned will dissolve more copal 
 than the menstruum will retain when cold. The most 
 economical method will therefore be, to set the vessel 
 which contains the solution by for a few days, and, when 
 it is perfectly settled, pour off the clear varnish, and leave 
 the residue for future operation. 
 
 The solution of copal thus obtained is very bright. It 
 is an excellent varnish for pictures, and would, doubtless, 
 be an improvement in japanning, where the stoves used 
 for drying the varnished articles would drive off the 
 camphor, and leave the copal clear and colourless in the 
 work. 
 
 To dissolve Copal in Spirits of Turpentine. 
 
 REDUCE 2 oz. of copal to small pieces, and put them 
 
 into a proper vessel. Mix a pint of the best spirits of 
 
 turpentine with one eighth of spirits of sal ammoniac; 
 
 shake them well together, put them to the copal, cork 
 
 28*
 
 330 MISCELLANEOUS RECEIPTS. 
 
 the glass, and tie it over with a string or wire, making a 
 small hole through the cork. Set the glass in a sand- 
 beat so regulated as to make the contents hoil as quickly 
 o.s possible, but so gently that the bubbles may be counted 
 as they rise from the bottom. The same heat must be 
 kept up exactly till the solution is complete. 
 
 It requires the most accurate attention to succeed in 
 this operation. After the spirits are mixed, they should 
 be put to the copal, and the necessary degree of heat b 
 given as soon as possible, and maintained with the utmos 
 regularity. If the heat abates, or the spirits boil quicker 
 than is directed, the solution will immediately stop, and 
 rt will afterwards be in vain to proceed with the same 
 materials; but if properly managed the spirit of sal 
 ammoniac will be seen gradually to descend from the 
 mixture, and attack the copal, which swells and dissolves, 
 excepting a very small quantity which remains undis- 
 solved. 
 
 It is of much consequence that the vessel should not 
 be opened till some time after it has been perfectly cold ; 
 for if it contain the least warmth when opened, the whole 
 contents will be blown out of the vessel. 
 
 Whatever quantity is to be dissolved, should be put 
 into a glass vessel capable at least of containing four 
 times as much, and it should be high in proportion to the 
 width. 
 
 This varnish is of a deep rich colour, when viewed in 
 the bottle, but seems to give no colour to the pictures 
 upon which it is laid. If it be left in the damp, it re- 
 mains racky, as it is called, a long time ; but if kept in 
 a warm room, or placed in the sun, it dries as well as 
 any other turpentine varnish, and when dry it appears 
 to be as durable as any other solution of copal. 
 
 Copal may also be dissolved in spirits of turpentine by 
 the assistance of camphor. 
 
 Turpentine varnishes dry more slowly than those made 
 with alcohol, and are less hard ; but they are not so lia- 
 ble to crack.
 
 MISCELLANEOUS RECEIPTS. 331 
 
 To dissolve Copal in fixed-Oil. 
 
 MELT, in a perfectly clean vessel, by a very slow heat^ 
 one pound of clear copal ; to this, add from one to two 
 quarts of drying linseed oil. When these ingredients are 
 thoroughly mixed, remove the vessel from the fire, and 
 keep constantly stirring it, till nearly cold ; then add a 
 pound of spirits of turpentine. Strain the varnish through 
 a piece of cloth, and keep it for use. The older it is, the 
 more drying it becomes. 
 
 This varnish is very proper for wood-work, house and 
 carriage painting. 
 
 Seed-lac Varnish. 
 
 TAKE three ounces of seed-lac, and put it, with a pint 
 of spirits of wine, into a bottle, of which it will not till 
 more than two-thirds. Shake the mixture well together, 
 and place it in a gentle heat, till the seed-lac appears 
 to be dissolved : the solution will be hastened by shaking 
 the bottle occasionally. After it has stood some time, pour 
 olF the clear part, and keep it for use in a well-stopped 
 bottle. The seed-lac should be purified before it is used, 
 by washing it in cold water, and it should be in coarse 
 powder, when added to the spirit. 
 
 This varnish is next to that of copal in hardness, and 
 has a reddish-yellow colour : it is, therefore, only to be 
 used where a tinge of that kind is not injurious. 
 
 Shell-lac Varnish. 
 
 TAKE five oz. of the best shell-lac, reduce it to a gross 
 powder, and put it into a bottle in a gentle heat, or a 
 warm, close apartment, where it must continue two or 
 three days, but should be frequently well shaken. The 
 lac will then be dissolved, and the solution should then 
 be filtered through a flannel bag; and, when the portion 
 that will pass through freely is come off it should be kept 
 for use in well-stopped bottles. 
 
 The portion which can only be made to pass through 
 the bag by pressure, may be reserved for coarse purposes.
 
 332 MISCELLANEOUS RECEIPTS. 
 
 Shell-lac varnish is rather softer than seed-lac varnish, 
 but it is the best of varnishes for mixing with colours to 
 paint with, instead of oil, from its working and spreading 
 better in the pencil 
 
 Varnish for Toys, Silvered Clock-faces, and Furniture, 
 not exposed to hardship. 
 
 DISSOLVE two ounces of gum-mastic, and eight ounces 
 of gum-sandrach, in a quart of alcohol ; then add four 
 ounces of Venice turpentine. The addition of a little of 
 the whitest part of gum-benjamin will render the varnish 
 less liable to crack. 
 
 Amber Varnish. 
 
 AMBER forms a very excellent varnish : its solution 
 may be effected by boiling it in drying linseed oil. 
 
 Oil-varnishes, which have become thick by keeping, 
 are made thinner with spirits of turpentine. 
 
 A Varnish for Copper-plate Prints. 
 PRETARE water by dissolving in it some isinglass ; lay 
 on, with a soft brush, a coat of this. Let dry. Put on 
 another, if necessary. Let dry. Then lay on another, 
 of the following varnish. True French spirit of wine, 
 half a pound; gum-elemi, two drachms, and sandarach, 
 three. 
 
 A curious and easy Varnish to engrave wtth aquafortis. 
 
 Lay on a copper-plate as smooth and equal a coat as 
 possible, of linseed oil. Set the plate on a gentle heat, 
 that the oil may congeal, and dry itself in. When you 
 find it has acquired the consistence of a varnish, then 
 you may draw with a steel point, in order to etch your 
 copper, and put on the aquafortis afterwards. 
 
 A Varnish to gild ivith, without Gold. 
 
 TAKE half a pint of spirits of wine, in which you dis 
 olve one drachm of saffron, and half a drachm of dra
 
 MISCELLANEOUS RECEIPTS. 333 
 
 gon's blood, both previously well pulverized together. 
 Add this to a certain quantity of shell-lac varnish, and set 
 it on the fire with two drachms of soccotrjne aloes. 
 
 Japan ning. 
 
 JAPANJTIXG is the art of varnishing in colours, and u 
 frequently combined with painting. 
 
 The substances proper for japanning, are wood, metal, 
 with all others which retain a determinate form, and are 
 capable of sustaining the operation of drying the var- 
 nish. Paper and leather, therefore, when wrought into 
 forms in which they remain stretched, stiff, and inflexible 
 are very common subjects for japanning. 
 
 The article to be japanned is first rendered smooth 
 and perfectly clean, it is then brushed over with two or 
 three coats of seed-lac varnish, (see under the head of 
 varnishes) except that the coarsest varnish will answer 
 the purpose. The varnish thus laid on is called the 
 priming. The next operation is to varnish the article 
 again with the best varnish previously mixed with a pig- 
 ment of the tint desired. This is called the grounding ; 
 if the subject is to exhibit any painting, the objects are 
 painted upon it, in colours mixed up with varnish, and 
 used in the same manner as for oil-painting. The whole 
 is then covered with additional coats of transparent 
 varnish, and all that remains to be done, is to dry and 
 polish it. 
 
 Japanning should always be executed in warm apart 
 men ts, as cold and moisture are alike injurious; and all 
 the articles should be warmed before any varnish is ap- 
 plied to them. One coat of varnish, also, must be dry 
 before another is laid on. Ovens are employed to hasten 
 the perfect drying of the work. 
 
 All the coloured pigments employed in oil or water, 
 answer perfectly well in varnish, combined with which 
 vehicle, many of those which fly in oil are perfectly 
 unchangeable. The manner in which the colours are 
 mixed with the varnish is extremely simple and easy ; 
 they are first reduced, by the usual means of washing
 
 334 MISCELLANEOUS RECEIPTS. 
 
 and levigation, to the finest state possible ; and the var 
 nish being contained in a bottle, they are added to it, till 
 the requisite body of colour is obtained, the mixture 
 being rendered complete by stirring or shaking the bottle. 
 When a single colour is intended, the varnish employed 
 is of no consequence, if it be hard enough for the work ; 
 and not possessed of any colour inconsistent with the tint 
 required ; but for painting with, shell-lac varnish is the 
 best, and easiest to work : it is, therefore, employed in 
 all cases where its colour permits, and for the lightest 
 colours, mastic varnish is employed, unless the fineness 
 of the work admits the use of copal dissolved in spirits 
 of wine. 
 
 To spare varnish, the priming may be composed of 
 size mixed with whiting, to give it a body, as some sub- 
 stances require much varnish to saturate them ; but 
 work primed with size is never durable ; it is liable to 
 crack and fly off- with the least violence, which never 
 happens to work into which the varnish can sink. Var- 
 nish cannot sink into metals, and this is the reason that 
 japanned metal, for exampte a japanned tin-plate tray, is 
 of less value than a paper one. The battering which 
 this piece of furniture sustains in its use, soon separates 
 the japan from it in flakes, or scales; which never hap- 
 pens to the paper, because the japan forms a part of its 
 substance. 
 
 It may be observed, that only wood, paper, leather, 
 and similar substances, require priming ; metals require 
 none, because they admit no varnish into them, and 
 therefore the ground is applied to them immediately. 
 
 The priming and grounds are all laid on with brushes 
 made of bristles : the painting will of course often re- 
 quire a camels'-hair pencil. 
 
 Of Japan Grounds. 
 
 Red. Vermilion makes a fine scarlet, but its appear- 
 ance in japanned work is much improved by glazing it 
 with a thin coat of lake, or even rose pink. 
 
 Indian lake, when good, is perfectly soluble in spirits
 
 MISCELLANEOUS RECEIPTS. 335 
 
 of wine, and produces a fine crimson, but is not often to 
 be obtained. 
 
 Yellow. King's yellow, turbith mineral, and Dutch 
 pink, all form very bright yellows, and the latter is very 
 cheap. Seed-lac varnish assimilates with yellow very 
 well ; and when they are required very bright, an im- 
 provement may be effected by infusing turmeric in the 
 varnish which covers the ground. 
 
 Green. Distilled verdigris laid on a ground of leaf 
 gold, produces the brightest of all greens; other greens 
 may be formed by mixing king's yellow and bright prus- 
 sian blue, or turbith mineral and prussian blue, or Dutch 
 pink and verdigris. 
 
 Blue. Prussian blue, orverditer glazed with Prussian 
 blue or smalt 
 
 White. White grounds are obtained with greater dif- 
 ficulty than any other. One of the best is prepared by 
 grinding up flock-white, or zinc-white, with one sixth of 
 its weight of starch, and drying it ; it is then tempered, 
 like the other colours, using the mastic varnish for com- 
 mon uses; and that of the best copal for the finest. Par- 
 ticular care should be taken, that the copal for this use 
 be made of the clearest and whitest pieces. Seed-lac 
 may be used as the uppermost coat, where a very deli- 
 cate white is not required, taking care to use such as is 
 least coloured. 
 
 Black. Ivory-black or lamp-black ; but if the lamp- 
 black be used, it should be previously calcined in a closed 
 crucible. 
 
 Black grounds may be formed on metal, by drying 
 Unseed oil only, when mixed with a little lamp-black. 
 
 The work is then exposed in a stove to a heat which 
 will lender the oil black. The heat should be low at 
 first, and increased very gradually, or it will blister. This 
 kind of japan requires no polishing. It is extensively 
 used for defending articles of iron-mongery from rust. 
 
 Tortoise-shell ground for metal. Cover the plates 
 intended to represent the transparent parts of the tor- 
 toise-shell, with a thin coat of vermilion in seed-lac
 
 336 MISCELLANEOUS RECEIPTS. 
 
 varnish. Then brush over the whole with a varnish 
 composed of linseed oil boiled with umber until it is 
 almost a black. The varnish may be thinned with oil 
 of turpentine before it is used. When the work is done, 
 it may be set in an oven, with the same precautions a* 
 the black varnish last named. 
 
 Polishing of varnished and japanned work. 
 
 PICTURES and other subjects, to which only a single 
 coat or two of thin varnish is given, are generally left to 
 the polish which the varnish naturally possesses, or 
 brightened only by rubbing it with a woollen cloth, after 
 it is dry; but wherever several coats of varnish or 
 japan are laid on, a glossy surface is produced by the 
 moans used to polish metals ; the surface having been 
 suffered to become completely dry and hard. 
 
 When the coat of varnish is very thick, the surface 
 may be rubbed with pumice-stone and oil, until it be- 
 comes uniformly smooth ; the pumice should first be 
 educed to a smooth flat face by rubbing it on a piece of 
 freestone, or something to answer the same purpose. 
 The japanned or varnished surface may afterwards be 
 rubbed with pumice reduced to an impalpable powder. 
 The finishing may be given bv oil and woollen rag only. 
 
 When the varnish is thinner, and of a more delicate 
 nature, it may be rubbed with tripoli or rotten-stone, in 
 fine powder, finishing with oil as before. When the 
 ground is white, putty or Spanish white, finely washed, 
 may be used instead of rotten-stone, of which the colour 
 might have some tendency to injure the ground. 
 
 Preparation of Drying Linseed Oil. 
 
 FREQUEVT reference has been made to the use of drying 
 linseed oil : it may be necessary to observe, that to render 
 linseed oil drying consists simply in mixing it with litharge, , 
 or any oxide of lead, boiling it slowly for some time, and 
 straining it from the sediments after it has stood to clarify. 
 The oil thus treated, beomes thicker as it imbibes oxygen 
 from the oxide, and acquires the property of drying much
 
 MISCELLANEOUS RECEIPTS. 337 
 
 sooner than before. An ounce of litharge may be used 
 MI every pound of oil. 
 
 To render Boots and Shoes water-proof. 
 TAKC one pint of drying oil, two ounces of yellow wax, 
 two ounces spirits of turpentine, and half an ounce of 
 Burgundy pitch, melt them over a slow fire, and thorough- 
 iy incorporate them by stirring. Lay this mixture on 
 new shoes and boots, either in the sun or at some dis 
 tance from the fire, with a sponge or brush, and repeat 
 Ihe operation as often as they become dry, until they are 
 fully saturated. The shoes and boots thus prepared, 
 ought not to be worn until the leather has become per- 
 fectly dry and elastic. They will then be found imper 
 vious to moisture, and their durability will be increased. 
 
 Method of preparing a cheap Substitute for Oil Paint. 
 
 IT often happens that people do not choose, or cannot 
 employ oil-painting in the country, either because it does 
 not dry soon enough, ana has a disagreeable smell, or 
 because it is too costly. Ludicke employed with the 
 greatest success the following composition for painting 
 ceilings, gates, doors, and even furniture. 
 
 Take fresh curds, and bruise the lumps on a grinding- 
 stone, or in an earthen pan or mortar, with a spatula. 
 After this operation, put them in a pot with an equal 
 quantity of lime, well quenched, and become thick 
 :nough to be kneaded : stir the mixture well, without 
 adding water, and a whitish semi-fluid mass will be ob- 
 tained, which may be applied with great facility like 
 paint, and which dries very rapidly. It must be employed 
 the day it is prepared, as it will become too thick the 
 following day. Ochre, armenian bole, and all colours 
 which hold with lime, may be mixed with it, according 
 to the colour desired ; but care must be taken, that the 
 addition of colour made to the first mixture of curds and 
 Jime, contain very nttle water, or it will diminish the 
 durability of the painting. 
 
 When two coats of this painting have been laid on it 
 29 W
 
 338 MISCELLANEOUS RECEIPTS. 
 
 may be polished with a piece of woollen cloth, or other 
 proper substance, and it will become as bright as varnish. 
 This kind of painting, besides its cheapness, possesses the 
 advantage of admitting the coats to be laid on and pol- 
 ished in one 3ay ; as it dries speedily, and has no smell 
 
 A Cemeit which answers for cast iron Pipes, or 
 wooden Logs. 
 
 TAKE 12 or 14 Ibs. of fine cast iron borings, put them 
 in a vessel with as much water as will just wet them 
 through; mix with them ^ Ib. of pounded sal ammo- 
 niac, and 2 oz. of flour of sulphur; mix all well together, 
 and let stand three or four hours : they are then ready 
 for use. If not used immediately, cover them with water 
 till used* 
 
 Bronzing. 
 
 BRONZE of a good quality acquires, by oxidation, a fine 
 green tint, called patina antiqua. Corinthian brass re- 
 ceives, in this way, a beautiful clear green colour. This 
 appearance is imitated by an artificial process, called 
 bronzing. A solution of sal ammoniac and salt of sorel 
 in vinegar is used for bronzing metals. Any number of 
 layers may be applied, and the shade becomes deeper in 
 proportion to the number applied. For bronzing sculp- 
 tures of wood, plaster-figures, &c., a composition of yel- 
 low ochre, Prussian blue, and lamp-black, dissolved in 
 glue-water, is employed. 
 
 Caoutchouc, or India Rubber, how dissolved, uses, fyc. 
 
 CAOUTCHOUC is brought principally from South Ameri- 
 ca : the juice, obtained from incisions, is applied in suc- 
 cessive layers, over a mould of clay, and dried by exposure 
 to the sun, and to the smoke from burning fuel. When 
 perfectly dry, the mould is broken, leaving the caout 
 chouc in the form of a hollow ball. It is insoluble in 
 alcohol and in water. Sulphuric ettier, when purified by 
 washing in water, dissolves it , and, by evaporation, the 
 may be discovered unchanged.
 
 MISCELLANEOUS RECEIPTS. 339 
 
 Oil of turpentine softens it, and forms with it a sort of 
 paste that may be spread as a varnish ; but it is very 
 long in drying. The fluid now commonly used to dissolve 
 it is the purified naphtha from coal tar, which is, at the 
 same time, a cheap and effectual solvent, and which 
 does not change its properties. This solution is employed 
 to give a thin covering of caoutchouc to cloth, which is 
 thus rendered impervious to moisture. Caoutchouc is 
 also readily soluble in cajeput oil. 
 
 Caoutchouc, from its softness, elasticity, and impene- 
 trability to water, is applied to the formation of cathe- 
 ters, bougies, and tubes for conveying gases. These 
 are formed by twisting a slip of it round a rod, and 
 causing the edges to adhere by pressure, when softened 
 by maceration in warm water. It is also used very ex- 
 tensively in this country for over-shoes ; and its solution 
 in oils forms a flexible varnish. 
 
 The following Composition will render Boots or Shoes 
 impervious to Water. 
 
 TAKE neat's-foot oil, and dissolve in it caoutchouc, a 
 sufficient quantity to form a kind of varnish ; rub this on 
 the boots. This is sufficient. 
 
 N. B. The oil must be placed where it is warm, the 
 caoutchouc put into it in parings. It will take several 
 days to dissolve it. 
 
 Jin excellent Salve for Cuts, Bruises, Sores, fyc. 
 
 TAKE l oz. of olive oil, 2 oz. of white diacula, and 2 
 oz. of bees'-wax ; let these ingredients be dissolved toge- 
 ther, and the salve is formed. This salve I have tried 
 to my satisfaction, and found it answer exceedingly well 
 
 Various Cements. 
 
 THE joints of iron pipes, and the flanges of steam en- 
 gines, are cemented with a mixture composed of sulphur 
 and muriate of ammonia, together with a large quantity 
 of iron chippings. 
 
 The putty of glaziers is a mixture of linseed oil and
 
 340 MISCELLANEOUS RECEIPTS. 
 
 powdered chalk. Plaster of Paris, dried by heal, and 
 mixed with water, or with rosin and wax, is used for 
 uniting pieces of marble. A cement composed of brick- 
 dust and rosin, or pitch, is employed by turners, and 
 some other mechanics, to confine the material on which 
 they are working. Common paint, made of white lead 
 and oil. is used to cement china-ware. So also are resi- 
 nous substances, such as mastic and shell-lac, or isinglass 
 dissolved in proof-spirit or water. The paste of book 
 binders, and paper-hangers, is made by boiling flour 
 [lice-glue is made by boiling ground rice to the consist- 
 ence of a thin jelly. Wafers are made of flour, isinglass, 
 yeast, and white of eggs, dried in thin layers upon tin 
 plates, and cut by a circular instrument. They are 
 coloured by red lead &c. Sealing-wax is composed of 
 shell-lac and rosin, and is commonly coloured with ver- 
 milion. Common glue is most usually employed for uniting 
 wood and similar porous substances. It does not answer 
 for surfaces impervious to water, such as metals, glass. 
 &c. The cements mostly used in building are composed 
 of lime and sand. The lime adheres to and unites the 
 particles of sand. Cements thus made increase in strength 
 for an indefinite period. Fresh sand wholly silicious and 
 sharp, is the best. That taken from the sea shore is 
 unfit for making mortar, as the salt is apt to deliquesce 
 and weaken the mortar. The amount of sand is always 
 greater than that of lime. From two to four parts of 
 sand are used, according to the quality of the lime and 
 the labour bestowed on it. 
 
 Jin excellent Cement for Paper, Cloth, fyc. or for the 
 use of Block-Cutters 
 
 [K fastening the hatting into the figures, is made by- 
 stirring a quantity of raw flour into a rather thin solution 
 of gum-senegal water. 
 
 Gilding. 
 
 THE art of gilding at the present day, is performed 
 either upon metals, or upon wood, leather, parchment,
 
 MISCELLANEOUS RECEIPTS. 34 1 
 
 or paper; and there are three distinct methods in 
 general practice, viz. wash, or water-gilding, in which 
 the gold is spread, whilst reduced to a fluid state, 
 by solution in mercury ; leaf-gilding, either burnished 
 or in oil, performed by cementing their leaves of gold 
 upon the work, either by size or by oil ; japanncr's- 
 gilding, in which gold dust or powder is used instead of 
 feaves. Gilding on copper is performed with an amalgam 
 of gold and mercury. The surface of the copper, being 
 freed from oxide, is covered with the amalgam, and 
 afterwards exposed to heat till the mercury is driven otF, 
 leaving a thin coat of gold. It is, also, performed by 
 dipping a linen rag in a saturated solution of gold, and 
 burning it to tinder. The black powder thus obtained 
 is rubbed on the metal to be gilded, with a cork dipped 
 in salt water, till the gilding appears. Iron or steel is 
 gilded by applying gold leaf to the metal after the sur- 
 face has been well cleaned, and heated until it has 
 acquired the blue colour, which at a certain temperature 
 it assumes. The surface is previously burnished, and the 
 process is repeated when the gilding is required to be 
 more durable. It is, also, performed by diluting a solu- 
 tion of gold in nitro-muriatic acid, with alcohol, and 
 applying to the clean surface. A saturated solution of 
 gold in nitro-muriatic acid, and mixed with three times 
 its weight of sulphuric ether, dissolves the muriate of 
 gold, and the solution is separated from the acid beneath. 
 To gild the steel, it is merely necessary to dip it, the sur- 
 face being previously well polished and cleaned, in the 
 ethereal solution, for an instant, and on withdrawing it, 
 to wash it instantly by agitation in water. By this method 
 steel instruments are very commonly gilt. 
 
 Method of Preparing and Using Glue. 
 
 SET a quart of water on the fire, then put in about 
 half a pound of good glue, and boil them gently together 
 till the glue be entirely dissolved, and of a due consistence 
 
 When glue is to be used, it must be made thoroughly 
 hot, after which with a brush dipped in it besmear the 
 29 *
 
 342 MISCELLANEOUS RECEIPTS. 
 
 faces of the joints as thick as possible ; then, c.apping 
 them together, glide or run them lengthwise one upon 
 another two or three times, to settle them close, so let 
 them stand till they are dry and firm. Parchment-glue 
 is made by boiling gently shreds of parchment in water, 
 in proportion of one pound of the former to six of the 
 latter, till it be reduced to one quart ; the fluid is then 
 strained from the dregs, and afterwards boiled to the 
 consistence of glue. Isinglass-glue is made in the same 
 way ; but this is improved by dissolving the isinglass in 
 alcohol, by means of a gentle heat. 
 
 China or Indian Ink. 
 
 DR. Lewis, on examining this substance, found that the 
 ink consisted of a black sediment, totally insoluble in 
 water, which appeared to be of the nature of the purest 
 lamp-black, and of another substance soluble in water, 
 and which putrefied by keeping, and when evaporated, 
 left a tenacious jelly, exactly like glue, or isinglass. It 
 appears probable, therefore, that it consists of nothing 
 more than these two ingredients, and probably may be 
 imitated with perfect accuracy by using a very fine jelly, 
 like isinglass, or size, and the finest lamp-black, and in- 
 corporating them thoroughly. The finest lamp-black 
 known is made from ivory shavings, and thence called 
 ivory black. 
 
 Ivory Dyeing. 
 
 THIS substance may be dyed or stained black, by a 
 solution of brass and a decoction of logwood ; a green, by 
 a solution of verdigris ; a red, by being boiled with Bra- 
 zil-wood in lime-water. 
 
 To prevent the smoking of lamp oil. 
 
 STEEP your wick in vinegar, and dry it well before 
 fou use it 
 
 Portable balls for removing spots from clothes in 
 
 general. 
 
 TAKE fuller's earth perfectly dried, so that it crumbles 
 to powder, moisten it with the clear juice of lerrons
 
 MISCELLANEOUS RECEIPTS. 343 
 
 and add a small quantity of pure pearlash ; then work 
 and knead the whole carefully together, till it acquires 
 the consistency of a thick elastic paste : form it into con- 
 venient small balls, and expose them to the heat of the 
 sur., in which they ought to be carefully dried. In this 
 state they are fit for use in the manner following: first 
 moisten the spot on the clothes with water, then rub it 
 with the ball just dissolved, and suffer it again to dry in 
 the sun: after having washed the spot with pure water 
 it will disappear. 
 
 Easy and safe method of discharging grease spots from 
 woollen. 
 
 FULLER'S earth, or tobacco-pipe clay, being first wet on 
 an oil spot, absorbs the oil as the water evaporates, and 
 leaves the vegetable or animal fibres of cloth clean, on 
 being beaten or brushed well. When the spot is occa- 
 sioned by tallow or wax, it is necessary to treat the part 
 cautiously by an iron on the fire, while the cloth is dry- 
 ing. In some kind of goods, bran or raw starch may be 
 used with advantage. 
 
 . To take spots out of Silk. 
 
 RUB the spots with spirits of turpentine : this spirit 
 exhaling, carries off with it the oil that causes the spot. 
 
 To take spots out of Cloths, Stuff's, Silks, Cotton and 
 
 Linen. 
 
 TAKE one quart of spring-water, put in it a little fine 
 white powder about the size of a walnut, and a lemon 
 cut in slices, mix these well together, and let it stand 
 twenty-four hours in the sun. This liquid takes out all 
 spots, whether pitch, grease, or oil, as well in hats, as 
 cloths and stuffs, silk or cotton, and linen. As soon as 
 the spot is taken out, wash the place with clean water, 
 for cloths of deep colour, add to a spoonful of the mix- 
 ture, a quantity of water to dilute it. 
 
 To render Cloth, wind and rain proof. 
 BOIL together 2 Ibs. of turpentine, and 1 Ib. of lith- 
 nr^e in powder, and 2 or 3 pints of linseed oil. The
 
 344 MISCELLANEOUS RECEIPTS. 
 
 article is then to be brushed over with this varnish, and 
 dried in the sun. 
 
 A Cement for broken Earthenware. 
 
 TAKE 1 oz. of dry cream cheese grated fine, and an 
 equal quantity of quick-lime mixed well together, with 
 9 oz. of skimmed milk, to form a good cement, when 
 he rendering of the joint visible is of no consequence 
 f mixed without the milk, it perhaps might be strongci 
 till. 
 
 To take Mildew out of Linen. 
 
 TAKE soap and rub it well ; then scrape some fine 
 chalk, and rub that also in the linen; lay it on the 
 grass ; as it dries wet it a little, and it will come out at 
 twice. 
 
 Soda Water, to make. 
 
 TAKE 20 grains tartaric acid, 25 grains super-carbonate 
 of soda: dissolve a lump of sugar, on which you have 
 poured a drop of oil of lemon in two wine-glass-fulls of 
 water: add the tartaric acid : stir it till dissolved. Then 
 dissolve the carbonate of soda in the like quantity of 
 water, and pour the two solutions quickly together, and 
 drink them off as rapidly as possible. 
 
 To cure six Hams. 
 
 TAKE 6 ozs. of salt-petre, 2 Ibs. 10 ozs. of fine salt, 
 4i Ibs. of brown sugar or 1 gallon of molasses. Rub 
 them with this mixture for one week every day ; then 
 put them into a strong pickle (salt and water) for one 
 month ; then smoke them, if to keep. Your pickle will, 
 fter the hams are taken out, be excellent for beef. 
 
 Elastic Cement for Bells. 
 
 Disso ,VE in good brandy, a sufficient quantity of isin- 
 glass, so as to be as thick as molasses. This composition 
 I am credibly informed answers the purpose remarkably 
 
 matt,
 
 MISCELLANEOUS RECEIPTS. 345 
 
 To soften Horn. 
 
 Take 1 Ib. of wood-ashes, add 2 Ibs. of quick-lime, put 
 them into a quart of water, let the whole boil until re- 
 duced to one-third, then dip a feather into it, if the 
 plume comes off on drawing it out, then it is boiled 
 enough ; when it is settled filter it off, and in the liquor 
 then strained add shavings of horn, Jet them soak for 
 three days, then rubbing oil on your hands work the horn 
 into a mass, and print or mould it into whatever shape 
 you want 
 
 Varnish for Harness. 
 
 Take | Ib. of Indian rubber, 1 gallon of spirits of tur 
 pentine, dissolve enough to make it into a jelly by keepini 
 almost new milk warm : then take equal quantities o 
 good linseed oil (in a hot state) and the above mixture 
 incorporate them well on a slow fire, and it is fit for use 
 
 4 Varnish for fastening the leather on top rollers in 
 Factories. 
 
 DISSOLVE 2f ozs. of gum-arabic in water, and add sc 
 much isinglass dissolved in brandy and it is fit for use. 
 
 The manner of soldering Ferrules for Tool-handles, fyc. 
 
 TAKE your ferrule, lap round the joining a small piece 
 of brass-wire, then just wet the ferrule, scatter on the 
 joining-ground, borax, put it on the end of a wire, hold it 
 in the fire till the brass fuses. It will fill up the joining, 
 and form a perfect solder. Ij rnay afterwards be turned 
 in the lathe. 
 
 To make White-wash that will not rub off. 
 
 Mix up half a pail full of lime and water, ready to put 
 on the wall ; then take ^ pint of flour, mix it up with 
 water, then pour on it boiling water, a sufficient quantity 
 to thicken it ; then pour it, while hot, into the white- 
 wash ; str all well together, and it is ready.
 
 3 *6 MISCELLANEOUS RECEIPTS. 
 
 An improved method of tempering Gravers, when 
 too hard. 
 
 HAVINCS heated a poker red-hot, hold the graver upon 
 it, within an inch of the point, waving it to and fro, till 
 the steel changes to a light straw colour; then, having 
 a piece of steel prepared for the purpose, with two nicks 
 filfd in it, one the shape of a lozenge, the other a square 
 graver edge ; when heated to a straw colour, put the 
 belly of the graver in one or other of the nicks, as the 
 shape may be, and instead of plunging it into water, tal- 
 low, or oil, hammer it on the back-side carefully, till 
 cold, and you will have a far superior tool, if rightly 
 managed, than by tempering the common way. This 
 method closes up the pores of the steel when heated, 
 and renders it more compact ; consequently, does not 
 break. It would be well for dentists to manage tools on 
 this principle, for good service and utility. 
 
 Easy way of cleaning 'the Hands, for Dyers, Col- 
 ourers, fyc. 
 
 TAKE a small quantity of pot-ash or pearl-ash in your 
 hand, pour into it a small quantity of water, rub it well 
 all over your hands with a little sand, then wash it off, 
 take in your hand a small quantity of chemic (chloride 
 of lime,) pour a little water into it, and rub it well on 
 the hands in a semi-liquid state ; wash the hands well in 
 water, and they will be clean. If not perfectly clean, 
 epcat the operation. , 
 
 Method of keeping the Hands soft and pliable in 
 all situations. 
 
 RUB the hands well in soap till a lather is produced ; 
 then rub on a sufficient quantity of sand to let the soap 
 and water predominate; after well rubbing, wash well 
 in warm water. Repeat this two or three times a day, 
 as circumstances may require, and the hands will be kept 
 perfectly soft
 
 Mi* ELLANEOUS RECEIPTS. 347 
 
 Ink-Powder. 
 
 INFUSE a 1 Ib. o galls powdered, and H ozs. of pome- 
 granate peels, in a , gallon of soft water for a week, in 
 a gentle heat, ami then strain off the fluid through a 
 cloth. After which add to it 4 oz. of vitriol dissolved in 
 a pint of water, ant let them remain for a day or two, 
 preparing in the n\ ,n time a decoction of logwood, by 
 boiling a half poun' 1 of the chips in a half gallon of 
 water, till one thin 1 oe evaporated, and then straining 
 the remaining fluid \\hile it is hot. Mix the decoction 
 and the solution of galls and vitriol together, and add 
 2) 7 ozs. of gum-arabic or the whitest of gum-senegal, 
 and then evaporate the mixture over a common fire to 
 1 quart, when the remainder must be put into a proper 
 vessel, and reduced to dryness, by placing it in a suf- 
 ficiently warm place, or letting it hang in boiling water. 
 After the whole of the liquid is evaporated, the residue 
 mu.-,t be well powdered. When wanted for use, all thai 
 is needed, is to dissolve the powder in water. 
 
 To give iron a temper to cut porphyry. 
 MAKE your iron red-hot, and plunge it into distilled 
 water from nettles, acanthus, and pilosella ; or in the 
 very juice pounded out from these plants. 
 
 To prevent irofl from rusting. 
 
 WARM your iron till you cannot bear your hand on it 
 without burning yourself. Then rub it with new and 
 clean white wax. Put it again to the fire till it has 
 oaked in the wax. When done, rub it over with a piece 
 of serge. This prevents the iron from rusting after- 
 wards. 
 
 To dye in Gold, Silver Medals, or laminas, through and 
 
 through. 
 
 TAKE Glauber salt, dissolve it in warm water, so as to 
 form a saturated solution. In this solution put a small 
 proportionate quantity of calx, or magister of gold. Then
 
 348 MISCELLANEOUS RECEIPTS* 
 
 put and digest in it, silver laminas cut small and thin, 
 and let them lay 24 hours over a gentle fire. At the end 
 of this term, you will find them thoroughly dyed gold 
 colour, inside and out. 
 
 An oH, one ounce of which will last longer than one 
 pound of any other. 
 
 TAKE fresh butter, quick-lime, crude tartar, and com- 
 mon salt, of each equal parts, which you pound and mix 
 well together. Saturate it with good brandy, and distil 
 it in a retort over a gradual fire, after having adapted 
 the receiver, and luted well the joints. 
 
 To make Corks for bottles. 
 
 TAKE wax, hog's lard, and turpentine equal quantities 
 or thereabouts. Melt altogether and stop your bottles 
 with it 
 
 jfn oil to prevent pictures from blackening. It may 
 serve, also, to make cloth to carry in the pocket against 
 wet weather. 
 
 PUT nut or linseed oil into a phial, and set it in the 
 sun to purify it. When it has deposited its dregs at the 
 bottom, decant it gently into another clean phial, and set 
 it again in the sun as before. Continue so doing till it 
 drops no more faeces at all. And with that oil, you make 
 the above described compositions. 
 
 To gild on Calf and Sheep Skin. 
 
 WET the leather with the white of eggs ; when dry, 
 rub it with your hand and a little olive oil, then put the 
 gold leaf and apply the hot iron to it. Whatever the 
 hot iron shall not have touched will go off by brushing. 
 
 To dye Wood Red. 
 
 TAKE chopped brazil wood, and boil it well in water 
 strain it through a cloth. Then give your wood two or 
 three coats, till it is the shade wanted. If wanted a 
 deep red, boil the wood in water impregnated with alum
 
 MISCELLANEOUS RECEIPTS. 349 
 
 and quick-lime. When the last coat is dry, burnish it 
 with the burnisher, and then varnish. 
 
 Another method to dye Wood Red. 
 
 TAKE vermilion and Spanish brown ; make them thiu 
 with linseed oil and turpentine. Rub it on with a cloth 
 in such a manner as to show the grain of the wood ; when 
 dry varnish. The proportion of vermilion and Spanish 
 brown, must be in proportion to the fineness of the shade 
 wanted. 
 
 To imitate Ebony. 
 
 INFUSE gall-nuts in vinegar, wherein you have soaked 
 rusty nails ; then rub your wood with this ; let it dry, 
 polish and burnish. 
 
 To produce various undulations on Wood. 
 
 SLACK some lime in chamber ley. Then with a brush 
 dipped in it, form your undulations on the wood accord- 
 ing to your fancy. And, when dry, rub it well with a 
 rind of pork. 
 
 To soften Ivory. 
 
 Iff three ounces of spirits of nitre, and fifteen of spring- 
 water, mixed together, put your ivory a soaking. And 
 in 3 or 4 days, it will be soft so as to obey your fingers. 
 
 To dye Ivory thus softened. 
 
 1. DISSOLVE, in spirits of wine, such colours as you want 
 to dye your ivory with. And when the spirit of wine 
 shall be sufficiently tinged with the colour you have put 
 in, plunge your ivory in it, and leave it there till it is 
 sufficiently penetrated with it, and dyed inwardly. Then 
 give that ivory what form you please. 
 
 2. To harden it afterwards, wrap it up in a sheet of 
 white paper, and cover it with decrepitated common salt, 
 and the driest you can make it to be ; in which situation 
 yon shall leave it only 24 hours. 
 
 30
 
 350 MISCELLANEOUS RECEIPTS. 
 
 To whiten ivory, even that which has turned a brr-wn 
 
 yellow. 
 
 1. SLACK some lime in water, put your ivory in thai 
 water, after decanted from the ground, and boil it till it 
 looks quite white. 
 
 2. To polish it afterwards, set it in the turner's wheel, 
 and after having worked it, take rushes and pumice- 
 stones, subtile powder with water, and rub it all till it 
 looks perfectly smooth, Next to that, heat it by turning 
 H against a piece of linen, or sheep-skin leather, and 
 when hot, rub it over with a little whitening diluted in 
 oil of olive ; then with a little dry whitening alone, and 
 finally with a piece of soft white rag. When all this ia 
 performed as directed, the ivory will look remarkably 
 white. 
 
 To whiten Bones. 
 
 PUT a handful of bran and quick-lime together, in a 
 new pipkin, with a sufficient quantity of water, and boil 
 t. In this put the bones, and boil them also till perfect- 
 ly freed from greasy particles. 
 
 To petrify Wood, $c. 
 
 TAKE equal quantities of gem-salt, rock-alum, white 
 vinegar, chalk, and pebbles powder. Mix all these in- 
 gredients together: there will happen an ebullition. If, 
 after it is over, you throw in this liquor any porous mat 
 ter, and leave it there a soaking four or five days, they 
 will positively turn into petrifactions. 
 
 A preparation for Tortoise-shell. 
 
 TAKE orpine, quick-lime, pearl-ashes, and aquafortis. 
 Mix well altogether, and put your horn or tortoise-shell 
 "n it to soak. 
 
 To dye Bones any colour. 
 
 UOIL the bones first for a good while ; then in a ley of 
 <juick-lime mixed with chamber ley, put either verdigris, 
 or red ar blue chalk or anv other ingredient fit to pro-
 
 MISCELLANEOUS RECEIPTS. 351 
 
 cure the colour you want to give to the bones. Lay the 
 bones in the liquor, and boil them, they will be perfectly 
 dyed. 
 
 To write on Silver with a black wliich will never go off 
 
 TAKE burnt lead, and pulverize it. Incorporate it next 
 with sulphur and vinegar, to the consistency of a paint 
 ing colour, and write with it on any silver plate. Let it 
 dry, then present it to the fire so as to heat the work a 
 little, and it is finished. 
 
 To restore Wine that is turned sour or sharp. 
 FILL a bag with leek-seed, or of leaves or twisters of 
 vine, and put either of them to infuse in the cask. 
 
 To correct a bad taste and sourness in Wine. 
 
 PUT in a bag the root of wild horse-radish cut in bits. 
 Let it down in the wine, and leave it there two days : 
 take this out, and put another, repeating the same till 
 the wine is perfectly restored. Or fill a bag with wheat : 
 it will have the same effect. 
 
 To cure those who are too much addicted to drinking 
 Wine. 
 
 Put in a sufficient quantity of wine, three or four 
 large eels, which leave there till quite dead. Give that 
 wine to the person you want to reform, and he or she 
 will be so much disgusted with wine, that though they 
 formerly made use of it, they will now have an aversion, 
 to it. 
 
 To increase the sharpness and strength of Vinegar. 
 
 BOIL two quarts of good vinegar, till reduced to one ; 
 then put it in a vessel and set it in the sun for a week. 
 Now mix the vinegar with six times its quantity of bad 
 yinegar in a small cask : it will not only mend it, but 
 aiake it strong and agreeable. 
 
 To make Vinegar with water. 
 
 PUT 30 or 40 Ibs. of wild pears in a large tub, where 
 you leave them three days to ferment. Then pour some
 
 352 MISCELLANEOUS RECEIPTS. 
 
 water over them, and repeat this every day for a montb 
 at the end of which it will make very good vinegar ; 
 the goodness of which may be increased by the abov* 
 method. 
 
 A dry portable Vinegar. 
 
 WAsh well half a pound of white tartar with xvarm 
 water, then dry it, and pulverize as fine as possible. 
 Soak that powder with good sharp vinegar, and dry i 
 before the tire or in the sun. Re-soak it as before wit 
 vinegar, and dry it as above, repeating this operation a 
 dozen of limes. By these means you will have a very 
 good and sharp powder, which turns water instantly into 
 vinegar. It is very convenient to carry in the pocket, 
 especially when travelling. 
 
 How to extract the essential oil from any flower. 
 
 TAKE any flowers you like, which stratify with com- 
 mon sea-salt in a clean earthen glazed pot. When thus 
 filled to the top, cover it well, and carry it to the cellar 
 Forty days afterwards put a crape over a pan, and empty 
 the whole to strain the essence from the flowers by pres- 
 sure. Bottle that essence and expose it 4 or 5 weeks in 
 the sun, and dew of the evening to purify. One single 
 drop of that essence is enough to scent a whole quart of 
 water. 
 
 To make Mutton Suet Candles, in imitation of Wax. 
 
 1. THROW quick-lime in melted mutton suet ; the lime 
 will fall to the bottom, and carry along with it all the 
 dirt of the suet, so as to leave it as pure and as fine as 
 wax itself. 
 
 2. Now if to one part of the suet, you mix three of 
 real wax, you will have a very fine, and to appearance 
 a real wax candle, at least the mixture could never be 
 discovered, nor even in the moulding way for ornaments.
 
 RECEIPTS ON DYEING. 
 
 RECEIPTS ON DYEING. 
 
 353 
 
 General remarks on Dyeing. 
 
 CLEANLINESS in dyeing is very essential. The vessel, 
 and the articles to be dyed, must be ridded of grease and 
 dirt ; as grease resists the colouring particles, and dirt 
 leaves a stain. 
 
 Soft water should always be used for dyeing. Vessels 
 used for dyeing small articles, should generally be wash 
 hand basons, small copper and tinned pans, and suf- 
 ficiently large that the dyeing liquor be not spilt by dip- 
 ping the article in and out when dyeing. 
 
 The quantity of liquor generally necessary for dyeing 
 a dress of muslin, crape, sarsnet, cambric, &c. is about 
 three quarts ; for a larger dress a proportionable quantity. 
 
 The dyeing utensils are simple, being composed of 
 tubs, kettles, horse, or a couple of lathed benches, for 
 the purpose of placing the goods upon, when they come 
 from the dye. The horse may be in form of a carpen 
 ters' stool. A doll which is used for beating blankets, 
 counterpanes, &c. in the tub in order to clean them. For 
 this doll some use an article similar to a pavior's mall, but 
 of smaller dimensions: others have a circular piece of 
 wood 2 inches thick, in which 4 legs are fastened, on the 
 under side, and in the centre a pretty long handle, with 
 a cross piece put through it to work it with. Against 
 the wall or a post, fasten a hook or pin to put on your 
 skeins, and with a small stick wring them out. In fancy 
 dyeing the various shades of cambric, a winch is in fre- 
 quent use. 
 
 The liquors should always be stirred with a spoon, rod, 
 01 any thing that is clean, previous to the article being 
 dipped in it, to cause the colouring particles to be equally 
 diffused, so that the article to be dyed receives its colour 
 uniformly, and it is also necessary that the article be 
 moved in and out quick, and opened to receive *ho 
 colour more evenlv. 
 
 30* X
 
 351 RECEIPTS ON DYEING. 
 
 Colours generally look much darker when wet, there- 
 fore, allowance should generally be made for drying, 
 which should always be done in a warm room, pinned of 
 tretched to a line. 
 
 (1.) Muming 
 
 Is a preparation necessary for some colours in order to 
 receive the colouring particles, such as crimson, scarlet, 
 purple, and some other colours. If any article is direct- 
 ed to be alumed, be careful to rid it well of the soap 
 suds, as alum turns soap to grease. When the article is 
 put in the alum liquor, it is to be well dipped in and out, 
 and opened, to receive this preparation more equally, 
 for an hour, or all night if circumstances admit, and when 
 alumed, it must be well wrung out, and rinsed in two 
 waters, and then dyed, the sooner the better, before get- 
 ting dry. NOTE. The aluming of silks ought to be done 
 cold, or it will be deprived of its lustre. 
 
 (2.) Preparing of the dye-liquors, or scalding the woods. 
 HAVING something like the end of a tub, about one 
 foot deep, with a copper bottom, bored full of holes 
 about a quarter of an inch in diameter ; lay a piece of 
 rather coarse sheeting on this, lay it altogether on another 
 tub; fill it with the wood to be scalded; then having 
 a copper-boiler full of boiling water, fill the tub which 
 contains the wood with boiling water, stir it during the 
 time it is going through ; fill it up again, and so repeat 
 the operation till you have got all the strength from the 
 wood. The criterion by which to know when the 
 strength is gone from the wood, is the paleness of the 
 liquor as it runs through. This operation is considered 
 superior to boiling the wood in a copper-boiler, especially 
 for the ground- woods ; but either way will answer. The 
 method of rendering the liquor stronger, of course, is by 
 evaporation, in a copper-vessel, with a constant fire un- 
 der it The chips of dye-woods are generally superior 
 to the ground-woods 1 as they are not so likely to be adul- 
 terated.
 
 RECEIPTS ON DYEING. 355 
 
 (3.) Pink on Silk. 
 
 AFTER aluming, (see receipt No. 1.) handle the goods 
 .o be dyed in peach-wood liquor, till the colour desired; 
 Ihen take out and put in a little alum liquor, handle the 
 poods a little longer, take out, rinse in water, and finish. 
 NOTC. In most cases, where the shade is not dark 
 enough, the operation must be repeated. 
 
 (4.) Brown on Silk. 
 
 ALUM your silk . (see No. 1.) Then take one part of 
 fustic liquor, and three parts of peachwood liquor; han- 
 dle in these till it becomes a good brown ; (a little log- 
 wood liquor will darken your shade, if required,) hedge 
 out, and put in a little alum-water; again put in your 
 goods, handle a little longer, then take out, drain, rinse 
 well, and finish. NOTE. By varying the peachwood and 
 fustic, various shades may be obtained. 
 
 (5.) Green on Silk. 
 
 TAKE green ebony, boil it in water, let it settle ; take 
 the clean liquor as hot as you can bear your hands in it, 
 handle in it your goods till of a bright yellow; then lake 
 water, and put in a little sulphate of indigo; handle your 
 goods in this till of the shade wanted. NOTE. The 
 ebony may previously be boiled in a bag, to prevent it 
 from sticking to the silk. 
 
 (G.) Sulphate of Indigo. 
 
 TAKE 3 Ibs of vitriol, 1 Ib. of ground indigo; put in a 
 little at a time, and keep stirring" till all dissolved. Let 
 tand 24 hours, and ready. 
 
 (7.) Blue on Silk. 
 
 IVDIGO, same as No. 5, green ; you will have a blue. 
 \OTE. The silk ought to be boiled in white soap and 
 water, and made quite white, and then rinsed in luke- 
 warm water
 
 356 RECEIPTS ON DYEING. 
 
 (8.) Black on Silk. 
 
 TAKE 1 oz. of bluestone of vitriol, 2 oz. of copperas, \ 
 oz. of nitrate of iron ; mix all together with as much 
 water as will do one piece; have the water a little 
 warm ; hedge in this six times, backward and forward, 
 take out, rinse in water; take another tub, put in it as 
 much logwood liquor, that has in it 1 Ib. of logwood, 1 
 oz. of fustic liquor ; hedge in this liquor with a sufficient 
 quantity of water, till black ; wash out, and finished. 
 NOTE. In both processes, let them have a chance to air 
 in drying. 
 
 (9.) Blue Black on Silk. 
 
 FIRST run through a mordant of nitrate of iron and 
 water, then run through pearl-ash water, then through 
 nitrate of iron again ; then put them through logwood 
 liquor, with a little bluestone of vitriol dissolved in it. If 
 not dark enough, repeat the operation. 
 
 (10.) Maroon on Silk. 
 
 To 3 Ibs. of silk, take \ Ib. of Cudbear, put it in wa- 
 ter, let it boil, then put in your silk, let it boil a few 
 minutes, keep your silk well handled, take out, and you 
 will have a good handsome colour. To change the 
 shade, put in 2 Ibs. of common salt : operate as before: 
 this will vary the shade. To vary it still further, take 
 the silk, after boiling it the first time without the salt, 
 handle it in pearl-ash water, or in cream of tartar, and 
 you will have a handsome blue. 
 
 (11.) Orange on Silk or Cotton. 
 
 TAKE 1 Ib.'of silk, 1 oz. of arnotta, 2 oz. of pearl-ash, 
 
 boil them well together, turn in your goods ; when boiled 
 
 10 minutes, take out, wash, and finished. 
 
 If this orange is dark, handle the goods at hand-heat 
 
 NOTE. These goods must be well washed out in soap 
 
 *nd in aluming them, you may use a little sugar of lead
 
 RECEIPTS ON DYEING. 357 
 
 (12.) Grey on Silk. 
 
 For a silk dress. Take 4 or 6 oz. of fine powdered 
 galls, pour on them boiling water, handle your silk in 
 this for 20 or 30 minutes; in another form, dissolve a 
 piece of green copperas, about the size of a nut ; handle 
 your silk through this, and it will be a grey, more or less 
 dark according to the quantity of drugs. 
 
 (13.) Slate on Silk. 
 
 To make a slate, take another pan of warm water 
 and about a tea-cup full of logwood liquor, pretty strong, 
 and a piece of pearl-ash, of the size of a nut ; take the 
 above grey-coloured goods, and handle a little in this 
 liquor, and it is finished. NOTE. If too much logwood 
 is used, the colour will be too dark. 
 
 (14.) Olive on Silk. 
 
 BY adding a little fustic liquor to the above slate, it will 
 form an olive : it may be necessary to run them through 
 a weak pearl-ash water to sadden -them. Wash in two 
 waters for the above three colours. They will keep 
 their colour very well. 
 
 (15.) Stone colour on Silk. 
 
 TAKE the coloured grey (see receipt No. 12.) Add a 
 sufficient quantity of purple archil to the grey liquor. 
 To give them a red sandy cast, add a little red archil : 
 simmer the silk in this a few minutes. Rinse in one or 
 two cold waters. Dry in the air. The red archil is 
 made from purple archil, by adding a small quantity of 
 vitriol*and water, which will redden it. 
 
 (16.) To dye a Silk Dress Brown. 
 TAKE 8 oz. of sumach ; 4 oz. of logwood ; 8 oz. of 
 camwood or madder; boil these drugs in water, then 
 cool down your liquor ; wet out your silks ; then enter 
 them ; handle well ; wash out as usual. For a mulber- 
 ry cast, add as much purple archil as may be necessary
 
 358 RECEIPTS ON DYEING. 
 
 (17) Drab on Silk, 
 
 FOR a silk dress. Take 4 oz. of archil, one oz M 
 madder; enter and handle the goods; this may be sad- 
 dened, by taking out your goods and dissolving in the 
 liquor a piece of green copperas, the size of a nut 
 again handle in this liquor ; or, what is still better, in- 
 stead of copperas, use a little pearl-ash to sadden with. ' 
 
 (18.) Dove on Silk. 
 
 TAKE Brazil logwood and sumach ; vary the quantities 
 as you want your shade; boil them in water, then enter 
 vour goods, handle well, and sadden with green copperas. 
 
 (19.) Yellow on Silk. 
 
 BOIL quercitron barks in a copper pan for 20 minutes, 
 any quantity you please. Dip out a sufficient quantity 
 to cover your silk, in another copper pan, or tinned ves- 
 sel, into which add a small quantity of muriate of tin ; 
 pass your silks first through warm water, and wring them 
 out ; then put them into this pan of dye-water, and han- 
 dle them with a clean stick, till cold ; when cold, take 
 out, throw out your liquor, take from the first pan as 
 much liquor as before, handle in this 10 minutes, then 
 add muriate of tin according to shade wanted. Rinse 
 out in its own liquor and dry in a warm room. Annetto 
 affords an orange yellow with equal quantities of pearl- 
 ash, and gives out its colour to silk in warm water. 
 Turmeric gives out its colour in a similar manner. The 
 roots of Barbary afford a yellow of themselves, when 
 boiled in water. 
 
 (20.) Crimson on Silk. * 
 
 TAKE Cudbear, boil it in water; then just rinse or 
 ..andle your silks in it for a few minutes, you have the 
 shade wanted. Chamber ley or any alkaline solution 
 will change the colour. 
 
 (21.) Flesh Colour on Silk. 
 
 HAVING first thoroughly cleaned your silk in the usual 
 . rinse in warm water: (lion handle thorn in a
 
 RECEIPTS ON DYEING. 359 
 
 very slight water 6*f alum and tartar, so slight that you 
 could hardly taste it. Then if you have been dyeing 
 Pinks, No. 3, receipt, take some of the old liquor, handle 
 in it till of the shade wanted. The liquor must not be 
 too strong, or the shade will be too heavy. 
 
 (22.) Brown on Woollen Cloth, or Clothes of any 
 description. 
 
 THE quantity of woods to be regulated according to 
 die quantity of goods to be dyed. For instance, a pair 
 of men's pantaloons, being first well cleaned from all 
 grease: take 1 Ib. of red-wood, hypernick, or peach- 
 wood ; 1 Ib. of fustic, put them in a copper kettle, boil 
 them, then cool down so as to bear in it your hand ; then 
 put in a small quantity of cream of tartar, agitate the 
 water; then enter your goods, handle them till they come 
 to a boil, let it boil 5 or 10 minutes; take out the goods, 
 put in a strong solution made of 4 oz. of copperas, again 
 cool down, re-enter the goods, again bring them to a 
 boil ; take out, rinse well in water, finished. 
 
 This process makes a good substantial brown, and 
 might be varied in the shade by varying the quantities 
 of woods in their proportion, also, by adding a little 
 alum in the saddening. This is somewhat of an olive 
 cast. 
 
 (23.) A Brown on the Red cast* 
 
 TAKE 2 of red-wood, 1 of fustic, proceed in everpre- 
 spect as in No. 22, receipt, the desired shade will be 
 required. The quantity of dye-woods may be regulated 
 according to the quantity of goods to be dyed, in No. 22 
 also, the copperas and tartar. On woollen of course. 
 
 (24.) Olive Brown. 
 
 FOR a pair of pantaloons, providing they weigh 3 Ibs 
 take 1 Ib. of fustic. 1 oz. of logwood, 4 oz. of common 
 Madder, 2 oz. of peachwood ; boil them up, then cool 
 down your liquor, enter your pantaloons, bring the liquor 
 to a boil, let it boil half an hour, occasionally turning
 
 
 
 360 RECEIPTS ON DYEING. 
 
 over; take out, cool down your liquBr, put in 2 oz. of 
 dissolved copperas, handle until deep enough. For wool 
 Any quantity of yarn may be dyed on the same prin 
 ciple. 
 
 (25.) A Brown inclining to Snuff. 
 
 TAKE any quantity of woollen goods, use for every 
 b. 1 or 2 Ibs. of logwood ; first put your logwood into 
 the copper vessel, bring it to a boil ; cool down, then 
 enter your goods, bring them to boil, half an hour or 
 longer, if a large quantity ; take out, wash and finished. 
 Put, however, a little sumach, about 2 oz. to the Ib. of 
 logwood. This will be a good shade of brown. To alter 
 this shade, put into your liquor a proportionally small 
 quantity of alum liquor, again enter the goods, you will 
 have a good handsome shade on silk, as well as woollen. 
 
 (26.) A Black inclining to Purple on Wool and Silk. 
 
 TAKE 4 Ibs. of logwood, 1 Ib. of sumach, boil them in 
 a sufficient quantity of water ; cool down with water 
 enough to dye 4 or 5 Ibs. of silk or wool ; enter the goods, 
 bring them to boil, for ten minutes ; take out, partly cool 
 down, put jn about 1 Ib. of copperas ; again enter your 
 goods, bring them to a boil, take out, wash and finish. 
 Chiefly intended for wool. 
 
 N. B. A pair of pantaloons or any other article which 
 is old, would not need to be so particular in quantity of 
 dyejStufls, nor length of time. It will also answer for 
 cotton, and that without sumach, if the sumach is not 
 at hand. This is intended chiefly for woollen. 
 
 (27.) A Black inclining to Brown on Silk and Woollen, 
 TAKE one part of sumach, one of logwood, one of hy 
 pernick or peachwood ; boil the dye-stufls, cool down 
 put in the silk or woollen according to the quantity of 
 your dye-woods, bring them to a boil, for ten minutes 
 take out the goods, cool down ; having put in a sufficient 
 quantity of dissolved copperas, again enter the goods 
 bring to a boil, take out, wash well and finish.
 
 RECEIPTS ON DYEING. 3o 1 
 
 To mix the copperas wit|j alum would materially alter 
 the shade, if a variety was wanted. This is chiefly in 
 tended for wool. 
 
 (28.) A Jet Black on Woollen or Woollen Cloth. 
 
 FOR 7 Ibs. of wool or woollen cloth, take 3 Ibs. cf log- 
 wood, fib. of sumach, f- Ib. of fustic; boil these drugs 
 in a sufficient quantity of water for 20 minutes, coo 
 down, put in your goods, bring to a boil half an hour 
 then take out, cool down your liquor; add copperas dis- 
 solved in water 1|- Ibs., blue stone of vitriol 2 oz. ; again 
 enter your goods, bring to a boil 15 minutes, take out, 
 wash well in cold water, and finish. 
 
 (29.) Blue Prussian on Woollen. 
 
 TAKE any quantity of calcined copperas, dissolve it in 
 warm water, strong, put in your goods, keep them well 
 handled till the water comes nearly to a boil, still hundle 
 15 minutes; then rinse the goods in cold water; get up 
 another kettle of 1 of urine to 3 of water, bring the 
 water to hand heat ; put in your goods, handle half an 
 hour ; again rinse in cold water ; get up another kettle 
 of water, hand heat, and for each Ib. of goods 3 oz. of 
 prussiate of potash, put some oil of vitriol in the kettle, 
 handle the goods half an hour, if the colour looks green, 
 add a little more vitriol, handle half an hour longer, take 
 out, wash in cold water, and finish. 
 
 (30.) Green on Wool. 
 
 For 6 Ibs. of yarn, worsted, or cloth, take 3 Ibs. of fus- 
 tic, f of alum; boil them in a kettle 10 minutes, partly 
 cool down ; then put in a small tea-cup full of sulphate 
 of indigo, rake it well up, enter yorir goods, bring up to 
 a boil, keeping the goods well handled, let boil 20 min- 
 utes, (if a larger quantity, boil longer in proportion,) take 
 out, and if not blue enough, add a little more sulphate 
 of indigo ; handle until deep enough. Rinse in cold wa 
 ter, a id finish. 
 31
 
 362 RECEIPTS ON DYEING. 
 
 This shade may be altered in a variety of ways, bj 
 adding a little camwood, or logwood, in the first boiling. 
 
 (31.) Lilac on Wool. 
 
 BOIL up any quantity of archil, according to the quan- 
 tity of goods you want to dye ; cool the liquor a little, 
 enter the goods, handle carefully, until the shade is deep 
 enough, without boiling the liquor, take out, wash, arid 
 finish. 1 Ib. of archil will dye 4^ Ibs of goods. Silk may 
 be dyed in the same way. The shades may be altered 
 by soda, pearl-ash, wine, or common salt, adding a little, 
 and re-entering the goods before washing, and handling 
 a little while longer. 
 
 (32.) Drab nn Woollen. 
 
 FOR about 15 Ibs of woollen goods, take f Ibs of weld, 
 9 oz. of madder, 4 oz. of logwood, 3 oz. of archil; put them 
 in water, bring them to a boil for 10 or 15 minutes, cool 
 down, enter the goods, boil 15 minutes, wind up; put in 
 1 ox. of alum, 1^ oz. of copperas, ground; boil a few 
 minutes longer, during which time, handle well ; take 
 out, wash, and finish. The above receipt may serve as 
 a standard of procedure for all the drab shades, which 
 may be altered at pleasure, that can be produced; only 
 varying the quantities of drugs, in some cases adding ar- 
 chil, and in others, a little sulphate of indigo. Red tartar 
 and camwood may also be used. The copperas and 
 alum may be varied in quantity, or increased, 01 the 
 alum left out; thus varying the whole round. 
 
 (33.) Red on Woollen. 
 
 FOR 10 Ibs. of woollen goods. Take 2 Ibs. of alum, 
 Ji Ib. of red tartar; boil the goods in this 1 hour; (if a 
 larger quantity of goods boil 'longer time) then boil up 
 4 \ Ibs. of peachwood in clean water, cool down to a 
 srald, put in 2 oz. of No. 1, tin liquor, enter the goods, 
 handle until dark enough, and finish. The goods must 
 u^t be washed oetween the 1st and 2d operation.
 
 RECEIPTS ON DYEING. 363 
 
 (34.) Slate on Woollen. 
 
 FOR 10 Ibs. of woollen goods. Take 10 Ibs. of sumach, 
 boil it up 10 minutes, cool down, put in your goods, bring 
 them to a boil a few minutes, take out, put in 4 Ibs. of 
 copperas, dissolve, cool down ; re-enter the goods, bring 
 them to a boil, take out, wash and finish. A quantity 
 of iron liquor, such as the calico-printers use, would be 
 preferable to copperas. This slate may be varied by 
 varying the proportion of copperas and sumarh ; also, by 
 adding a little peachwood, or any other red-wood ; in thu 
 case, less copperas might be used. 
 
 (35.) Yellow on Wool 
 
 FOR 10 Ibs. of wool. Bring a kettle of water to a 
 scald or 180 degrees of heat, put in 4 Ibs. of quercitron 
 bark, (do not allow it to boil, as that would fetch out the 
 tanning and dull the yellow) 1 Ib. of alum, 6 oz. of 
 cream of tartar, nearly a half pint of No. 1, tin liquor; 
 stir up the liquor well, allow it to settle 15 minutes; 
 enter the goods, keep in until dark enough. 
 
 (36.) Orange on Wool. 
 
 FIRST dye the pattern to a full yellow. Then take a 
 clean kettle of water, when a little warm, put in for the 
 above goods 2 Ib. of madder, peachwood, mongeat, or 
 hypernick ; mongeat does very well : put in your goods, 
 keep them well handled, bring the goods to a boil, let 
 boil till dark enough, wash and finished. 
 
 \ARIOUS SHADES OF FANCY DYEING ON 
 COTTON. 
 
 (37.) For any quantity of Thread in Black. 
 
 FIRST take the thread, boil it in sumach and water; 
 then let it be immersed in lime-water, cold ; then in 
 weak copperas water, cold; then in lime-water again, 
 cold; then in logwood liquor, warm; take out, put some 
 copperas liquor into your logwood liquor, again put in 
 your goods, handle and finish. This makes a first-rate 
 black.
 
 364 RECEIPTS ON DYEING. 
 
 (38.) Turmeric yellow. 
 
 TAKE about 3 Ibs. of turmeric, put it in a small tu* 
 for the purpose, pour on it a tumbler of oil of vitriol, stir 
 it well up, then pour on it hot water, about two gallons, 
 stir this well up; then having half a tub-full of water, 
 boiling hot from the boiler, pour on it the contents of the 
 small tub ; enter three pieces, 30 yards each, give them 
 6 or 8 ends, as the workmen term it, fold up ; the next 
 process, have another tub of water, put in it half a pale 
 full of alum liquor, give the pieces 3 or 4 ends in this, 
 take out and finish. Renew with the same quantity for 
 the next 3 pieces, and so proceed. NOTE. By the ends 
 is meant rinsing the pieces backward and forward over 
 the wince in the tub. A half a hogshead will answer 
 the purpose. 
 
 It will be understood that these cotton colours are in- 
 tended for linings or cambrics. It will also be understood 
 that the liquors must be prepared as in receipt, No. 2, 
 or by boiling in a copper-cistern; the former is most 
 generally adopted for this kind of dyeing. It will be 
 necessary to have a number of tubs for the different li- 
 quors; an'd in dyeing various shades, to have the liquors 
 prepared in readiness. 
 
 (39.) Green on Cotton. 
 
 TAKE as much hot fustic liquor as will cover 3 pieces, 
 in which is put a very litt'e lime liquor, put it in a tub, 
 enter your goods, give them a ends, hedge them out; 
 take another tub, half full of water (cold), put into it a 
 sufficient quantity of blue-stone of vitriol liquor, to set 
 the tub, about two quarts, enter your goods in this, give 
 them five ends, hedge out, then take a couple of pail- 
 fulls of the fustic liquor, renew the first tub, enter 3 
 pieces more, and so proceed as at first ; then renew your 
 blue vitriol tub with half the quantity of liquor, not 
 taking any out, and proceed as at first. In this way do 
 as many the first and second time, as you can finish that 
 iiy; then commence to finish them. Take half a tub
 
 RECEIPTS ON DYEING. 365 
 
 full of old fustic liquor that has been used once, and put 
 to it H pail-fulls of logwood liquor ; enter your pieces 
 3 at a time, give them five ends, and finish. Renew with 
 a little more logwood liquor, enough to make them dark 
 enough, having first thrown away a couple of pail-fulls 
 from the tub, and rene^f with the same from the old tub, 
 and so proceeed in finishing. 
 
 (40.) Buff on Cotton. 
 
 TAKE as much hot fustic liquor and water, as will half 
 fill a tub, enter 3 pieces, give them 5 ends, hedge out ; 
 take another tub of lime-water cold, enter the same 
 pieces, and give them 5 ends in this, take out, and in a 
 short time they will be buff Renew your first and 
 second tub, and proceed as at first. This is all required 
 for buff 
 
 (41.) Jlnnetto Orange on Cotton. 
 
 HAVING prepared your annetto liquor by boiling it in 
 a copper vessel for 20 minutes ; take out your liquor, put 
 it in a tub ; partly fill your boiler with water, bring it to 
 a boil, having kept in the boiler the sediment of the 
 annetto, make it strong enough with annetto liquor, to 
 the shade you want to dye; enter 3 pieces when boiling, 
 give them 3 ends, take out ; enter them into cold alum 
 water, give them 4 ends, take out and finish. Renew 
 your annetto boiler with a sufficient quantity of annetto 
 liquor, and proceed as before ; then renew your alum 
 tub, proceed as before in the 2d process. This finishes 
 them. 
 
 The liquor that is left in the boiler at night, will do to 
 boil the annetto in the next day, so that nothing is lost. 
 
 (42.) Red on Cotton. 
 
 TAKE 3 pieces, enter them into a tub with hot red- 
 wood, or peach-wood liquor, give them 5 ends, then run 
 them into your wince ; have another tub called the spirit 
 tub close by, half full of cold water, put into it about y 
 tumblers full of spirits; then run the pieces from the 
 81*
 
 366 RECEIPTS ON DYEING. 
 
 other wince over the wince of the spirit tub, give them 
 5 ends in the spirit tub, then wind them on the wince of 
 the spirit tub, then back again to the red tub; give them 
 5 ends without having renewed the tub, they are finished 
 Throw away the red tub liquor, put in fresh liquor 
 and proceed as before; but the* spirit tub must be re- 
 newed always; even at night it may be left in a tub, and 
 renewed the next day. 
 
 (43.) Brown on Cotton. 
 
 THE first process is to give them 5 ends in hot sumach 
 liquor, or let them lay all night in the large tub, same as 
 for blacks; then give them 5 ends in copperas, hedge* 
 out, give them 5 ends in lime tub ; then hedge out, lay 
 them one side till you get enough to finish that day. You 
 next renew your tubs and repeat the operation as before. 
 Then comes the finishing part Make up a tub of hot 
 red-wood liquor j enter 3 pieces, give them 5 ends, put 
 the pieces one side the tub, put in some alum liquor, stir 
 up, give them 5 ends more, hedge out and finished. 
 
 (44.) Drab on Cotton. 
 
 TAKE half a tub of hot sumach, and fustic liquor ; 
 more fustic than sumach, according to shade wanted ; 
 enter 3 pieces, give them 5 ends, hedge out ; give them 
 5 ends in the copperas tub, and finished. Renew your 
 tubs, and proceed as before. The copperas tub is a half 
 a tub of water, with a couple of pail-fulls of copperas 
 liquor to set it in the first place ; renewed each time. 
 
 (45.) Slate on Cotton. 
 
 MAKE up a tub of about 2 of logwood to one of fustic 
 liquor, both hot ; enter 3 pieces, give them 5 ends, hedge 
 out; give them 5 'ends in copperas liquor; have it 
 stronger or weaker according to shade wanted. This 
 finishes them. Renew your tubs, and proceed as before. 
 
 (46.) Purple on Cotton. 
 
 GET up a tub of hot logwood liquor, enter 3 pieces 
 give them 5 ends, hsdge out ; enter them into a clean alum
 
 RECEIPTS ON DYEING. 3G7 
 
 ub, give them 5 ends, hedge out ; get up another tub of 
 iogvvood liquor, enter, give them 5 ends, hedjje out ; re 
 uevv your alum tub, give them 5 ends in that, and finish 
 
 (47.) Black on Cotton. 
 
 FIRST take your pieces and boil them in sumach liquor 
 in a large copper vessel, if you have it, that will hold fiO 
 or 70 pieces, in which you put about a bushel and a 
 haif of sumach ; let them stay all night if it is conve 
 nieni ; take out, and enter them into the lime-tub, 3 a 
 a time, give them 4 ends, hedge out; enter them into the 
 copperas tub, give them 5 ends, hedge out ; enter them 
 into the. lime again, give them 4 ends, hedge out ; enter 
 them h.to another tub with tolerably strong logwood 
 liquor, give them 5 ends ; put them to one side of the 
 tub, put in enough of copperas liquor to blacken them, 
 (about a couple of quarts,) then give them a few more 
 ends, and tney are finished. With this process, it is the 
 same as with the greens. After sumaching, liming, cop- 
 perassing, and second lining is repeated, till you get as 
 many as will answer you to finish that day, the tubs 
 being renewed after each 3 pieces : then comes the fin- 
 ishing ; after each 3 pieces, the logwood and copperas- 
 liquor is thrown awav, because the copperas kills the log- 
 wood, and so rendeis it unfit for the next pieces. I f is 
 frequently the case, that instead of the first process of 
 sumach boiling, they collect the old sumach, and fustic, 
 and logwood liquor, that has no copperas or lime in it, 
 into a large tub, and all the pieces that are spoiled in the 
 other colours, they th 4 ow them into this tub, let them lay 
 a few days till they are ready to dye blacks, and this 
 answers instead of the sumaching. 
 
 For the foregoing cotton shades, the pieces are first 
 taken and boiled in a wood or copper cistern, as circum- 
 stances may be, in order to take out the sizing, and pre- 
 pare them to receive the dye. 
 
 (48.) To put a fine gloss on Silk. 
 TAKE a fair white potato, cut it in very thin slices 
 pour oil it boiling water, let stand till rather cool, take
 
 3(58 RECEIPTS ON DYEING. 
 
 out the slices of potato, run your silk through this water 
 squeeze out, smooth while damp, and you will have a 
 very superior gloss. I tried this on black silk, and found 
 it to answer well. If it should not answer on lighter 
 colours, try the following one. If a quantity of silk, of 
 course proportion your potatos. 
 
 (49.) Another way 
 
 INSTEAD of a potato, use a small quantity of isinglass, 
 dissolved in water. Use it the same PS the above in 
 every particular, one oz. of isinglass will answer 1 Ib. of 
 silk. 
 
 (50.) Names of the principal Dyeing Materials. 
 
 ALUM, argal, or tartar, green copperas, verdigris, blue 
 vitriol, quercitron, and oak bark, mahogany-sawdust, 
 with acetate of alumine, mordant forms a good orange 
 inclining to flesh colour ; fenugreek, logwood, fustic, IJra- 
 zil wood, braziletto, camwood, barwood, and all other 
 redwoods, peachwood, sumach, galls, weld, madder of 
 various kinds, safflower, savory, green ebony, annalto, 
 turmeric, archil, cudbear, cochineal, lac-dye, indigo, and 
 tarzabonica or catecheu. This last drug, is now usea 
 extensively in colour-making and dyeing, treated \vith 
 sal ammoniac, pearlash, bicromate of potash, &c, 
 
 (1.) Pearlash mordant, with walnut husks, produces 
 a nankeen. 
 
 (52.) JVb. 1, Tin Liquor. 
 
 TAKE 2 quarts muriatic acid ; killed with 24 oz. o( 
 granulated tin. This will answer for woollen, or cotton 
 
 (53.) JVb. 2, Tin Liquor for Yellows on Woollen. 
 
 ABOUT 4 parts of muriatic to one of sulphuric, killed 
 with granulated tin. This will answer for vellow on 
 cotton also. 
 
 (54.) Tin Liquor for Pinks, Scarlets, Crimson, fyc. 
 I OF muriatic, 1 of nitric acids, killed with tin
 
 RECEIPTS ON DYEING. 369 
 
 (54.) Tin Liquor, for Scarlet, Crimson, fyc. on Silk. 
 
 TAKE 1 Ib. of nitric, and 1 Ib. of muriatic acids; about 
 1 1 oz. of sal ammoniac ; kill with granulated tin. 
 
 . (55.) The manner in which the French Madder ii 
 marked according to quality. 
 
 FIRST quality marked E. K. F. 2d Quality E. S. F. F. 
 3d Quality S. F. F. 4th Quality S. F. 
 
 (56.) To set an Indigo Vat for Cotton. 
 
 HAVING a sufficiently large vat, nearly fill it with water, 
 put in 30 Ibs. of ground indigo, 50 Ibs. of copperas, 50 
 Ibs. of slacked lime ; occasionally stir it up for two days. 
 When perfectly settled, it is ready for use. When the 
 vat is exhausted, renew with 4 Ibs. of pearlash, 4 Ibs. of 
 lime, and 12 Ibs. of copperas. 
 
 (57.) A Blue Vat for Silk and Woollen. 
 
 TAKE 8 Ibs. of indigo, about 2 gallons of vinegar, work 
 it in the mill till fine; if this is not convenient, put them 
 on a slow fire for 24 hours, till dissolved ; put in 1 Ib. of 
 madder, mix these well, and put them into a vat con- 
 taining 100 gallons of urine, stir well twice a day, for 
 1 week. It may then be worked, always previously 
 stirring it. This vat continues to be good till exhausted. 
 Nazarine blues, and deep purples, may be managed with 
 this vat and archil dye, taking care to rinse it well from 
 one to the other. Archil forms a dye of itself without 
 mordant, on silk and woollen, when boiled in water. 
 
 (58.) To dye Straws Red. 
 
 BOIL ground Brazil-wood in a ley of potash, and boil 
 your straws in it. 
 
 (59.) Blue on Straw. 
 
 TAKE a sufficient quantity of potash-ley, 1 Ib. of litmus 
 or lacmus-ground, make a decoction of, and then put in 
 the straw, and boil it.
 
 370 RECEIPTS ON DYEING. 
 
 (00.) Turkey-red on Leather. 
 
 AFTER the skin has been properly prepared with 
 sheep, pig's-dung, &c., then take strong nlum-water, and 
 sponge over your skin ; when dry, boil a strong gall 
 liquor, (it cannot be too strong ;) then boil a strong Bra- 
 zil-wood liquor, the stronger the better; take a sponge, 
 dip it in your liquor, and sponge over your skin ; repeat 
 this, till it comes to a full red : to finish your skin, take 
 the white of eggs and a little gum-dragon, mix the two 
 together in half a gill of water, sponge over your skin 
 and when dry, polish it with a bottle, or piece of glass 
 prepared for the purpose. 
 
 -(61.) Yellow on Leather. 
 
 INFUSE quercitron bark in vinegar, in which boil a 
 little alum, and brush over your skins with the infusion 
 finish same as the red. 
 
 (62.) Another Yellow. 
 
 TAKE a pint of whiskey, 4 oz. of turmeric ; mix them 
 well together; when settled, sponge your skin over, and 
 finish it the same way as the red. 
 
 (63.) Blue on Leather. 
 
 FOR each skin, take 1 oz. of indigo ; put it into boiling 
 water, and let it stand one night ; then warm it a little, 
 and with a brush, smear the skin twice over, finish same 
 as the red. 
 
 (64.) Black on Leather. 
 
 PUT your skin on a clean board, sponge it over with 
 gall and sumach liquors strong, then take a strong log 
 wood liquor, sponge it over 3 or 4 times; then take a lit- 
 tle copperas, mix it in the logwood liquor sponge over 
 rour skin, and finish it same as the red. 
 
 (65.) Different Shades on Leather. 
 
 THE pleasing hues bf yellow, brown, or tan colour, are 
 eadily imparted to leather by the following simple pro-
 
 JIECEIPTS ON DYEING. 371 
 
 cess. Steep saffron in boiling water for a number of 
 hours, wet a sponge or soft brush in the liquor, smear the 
 leather. The quantity of saffron, as well as of water, 
 will of course depend on how much dye may be wanted, 
 arid iheir relative proportions on the depth of colour re- 
 quired. 
 
 (GO.) To dye Leather purple. 
 
 FIRST sponge the leather with alum liquor strong, 
 then with logwood liquor strong, or mix them both and 
 boil them and sponge with the liquor : finish same as 
 for red.
 
 HYDRAULIC PRESSES, OF THE BEST DESCRIPTION, 
 
 MADE TO ORDER, BY ISAAC ADAMS & CO. 
 
 BOSTON.
 
 A 
 
 SUPPLEMENT 
 
 TO 
 
 THE ARTIST'S GUIDE 
 
 AND 
 
 MECHANIC'S OWN BOOK 
 
 WITH 
 
 PRACTICAL RULES AND TABLES 
 
 FOE 
 
 ENGINEERS, MILLWRIGHTS, MACHINE MAKERS, CARPENTERS, 
 BRICKLAYERS, SMITHS, Ac., 
 
 CONNECTED WITH 
 
 THE STEAM ENGINE, WATER WHEELS, PUMPS, AND 
 MECHANICS IN GENERAL. 
 
 TO WHICH IS ADDED 
 
 THE MANAGER'S ASSISTANT IN A COTTON MILL, 
 
 FROM THE HAW MATERIAL INTO YARN AND CLOTH. 
 
 BY JAMES PILKINGTON 
 
 BOSTON: 
 
 PUBLISHED BY BROWN AND TAGGARD, 
 
 25 & 29 CORN HILL. 
 
 1860.

 
 STEAM ENGINE. 
 
 I TRUST! shall not be thought impertinent, and, I hope, 
 not partia', iu recommending one ot the latest, and I may 
 safely say, the best improvement as yet known, for tha 
 economical usingof fuel; it is Mr. Bruuton's Fire Regula- 
 tor. This machine feeds the fire in the most regular man- 
 ner, and nicely proportions the quantity of coal thrown 
 upon the grate, to the quantity of steam required. 
 
 Almost the whole of the, public .works using steam en- 
 gines in London, have this Fire Regulator attached to their 
 boilers. And the accounts kept by their engineers, of the 
 quantity of coal consumed, exhibit a saving of from 15 to 
 25 per cent, produced by it. But the regular manner of 
 feeding the fire, and. consequently, the savin<>: of fuel, aie 
 not the only advantages derived from it. There is no re- 
 gular fireman needed, the hopper only requires to be filled 
 with coal in the morning, and no other at ten da nee is neces- 
 sary; also the supplementary boiler, which is attached to 
 the large boiler, gives an additional quantity of steam, say 
 from 2 to G horses, iu proportion to the size of the engine, 
 and preserves the large boiler from the injurious effects of 
 the fire. 
 
 These advantages, derived from this Fire Regulator over 
 the usual mode of feeding the fire by hand, make it one of 
 the most useful inventions of the present day, and, iu fact, 
 a steam engine is not complete without it. 
 
 Since the last edition of the Compendium was published, 
 Mr. Brunton has added a further improvement to his Firs
 
 376 STEAM ENGINE. 
 
 Regulator, by which he is enabled to apply it immediately 
 under round boilers or stills. In this improved state it is 
 now at work under the stills of Messrs. Thomas Smith & 
 Co. Whitechapel Distillery, who find it to effect a very con- 
 siderable saving in fuel and attendance. 
 
 BOILERS are of various forms, but the most general ia 
 proportioned as follows, viz. width 1, depth 1.1, length % 2.5 ; 
 their capacity being, for the most part, two horse power 
 more than the power of the engine for which they are in- 
 tended. These are the proportions of the wagon boilers, 
 hut the cylindrical boiler with a flue through it, is now fre- 
 quently used, and is much the stronger boiler ; it is also 
 better adapted than the other for quickly generating steam, 
 there being more heating surface exposed in proportion to 
 the volume of water ;* but for a stationary engine that is 
 daily employed, the elliptical boiler is preferable; it con- 
 tains a greater body of water than the cylindrical, and 
 though the steam cannot be got up so exppditiously, yet, 
 when it is up, it can be kept at a more uniform pressure, 
 being less susceptible of any variation in the temperature 
 of the furnace. 
 
 Boulton and Watt allow 25 cubic feet of space for each 
 horse power, some of the other engineers allow 5 feet of 
 surface of water. 
 
 STEAM arising from water at the boiling point, is equal 
 to the pressure of the atmosphere, which is, in round num- 
 bers, 15 libs on the square inch ; but to allow for a con- 
 stant and uniform supply of steam to the engine, the safety 
 valve of the boiler is loaded with 3 libs on each square 
 inch. 
 
 Where boilers are in good order and sufficiently strong, 
 it is advisable to use steam at a pressure of 10 libs instead 
 of 3 libs, as stated above. Steam at this pressure is, con- 
 sequently, much more effective, and the engine performs its 
 work with greater ease ; but to use steam of this pressure, 
 
 * Csmtnon pressure boilers ought to expose, for each horse power, 
 12 square feet of surface to the heat of the furnace and about f of a 
 quarc foot of grate surface for one horse.
 
 STEAM ENGINE. 
 
 37? 
 
 the feed pipe of the boiler requires to be lengthened. The 
 following Table gives the vertical heights for different 
 pressures. Beyond 15 libs pressure a force pump is gene- 
 rally used instead of a vertical feed pipe, because the grcal 
 length would not only be inconvenient, but liable toacci- 
 dent. When the steam is at this pressure it can be used 
 expansively, that is, the valve can be shut at half a threa 
 quarter stroke, and the remainder of the stroke supplied 
 by the expansion of the steam to common pressure; mis 
 is found a very economical mode of working an engine. 
 
 TABLE. 
 
 T,ibs Pressure 
 on thi- Square inch 
 of the area of 
 Safety Valve. 
 
 Feet of Vertical Knight of 
 Feed Pipe 
 measured from 
 Water Line in Holler. 
 
 5 libs 
 
 13 feet. 
 
 6 
 
 15 
 
 7 
 
 18 
 
 8 
 
 20 
 
 9 
 
 23 
 
 10 
 
 25 
 
 11 
 
 28 
 
 12 
 
 30 
 
 13 
 
 33 
 
 14 
 
 35 
 
 15 
 
 38
 
 378 
 
 STEAM ENGINE. 
 
 The following Table exhibits the expansive force 01 
 Bieaiii. expressing the degrees of heat at each lit of pre* 
 sure on the safety valve. 
 
 *>, 
 
 rrrf8 of 
 Heat. 
 
 Lihsot 
 Pressi.it. 
 
 i 
 
 Deprfipsof 
 Heat. 
 
 I.ihs of 
 Pressure. 
 
 ^Tat ' 
 
 Libs of 
 Pressure. 
 
 2120 
 
 
 
 268 
 
 24 
 
 298 
 
 48 
 
 216 
 
 1 
 
 270 
 
 25 
 
 299 
 
 49 
 
 219 
 
 2 
 
 271 
 
 26 
 
 300 
 
 50 
 
 222 
 
 3 
 
 273 
 
 27 
 
 301 
 
 51 
 
 225 
 
 4 
 
 274 
 
 28 
 
 302 
 
 52 
 
 229 
 
 5 
 
 275 
 
 29 
 
 303 
 
 53 
 
 232 
 
 6 
 
 277 
 
 3D 
 
 304 
 
 54 
 
 234 
 
 7 
 
 278 
 
 31 
 
 3U5 
 
 55 
 
 236 
 
 8 
 
 279 
 
 32 
 
 306 
 
 56 
 
 239 
 
 9 
 
 2*1 
 
 33 
 
 31,7 
 
 57 
 
 241 
 
 10 
 
 282 
 
 34 
 
 3(8 
 
 58 
 
 244 
 
 11 
 
 283 
 
 35 
 
 3U9 
 
 59 
 
 246 
 
 12 
 
 285 
 
 36 
 
 310 
 
 60 
 
 248 
 
 13 
 
 286 
 
 37 
 
 311 
 
 61 
 
 250 
 
 14 
 
 287 
 
 38 
 
 312 
 
 62 
 
 252 
 
 15 
 
 288 
 
 39 
 
 313 
 
 63 
 
 254 
 
 16 
 
 289 
 
 40 
 
 313| 
 
 64 
 
 256 
 
 17 
 
 290 
 
 41 
 
 314 
 
 65 
 
 258 
 
 18 
 
 291 
 
 42 
 
 315 
 
 66 
 
 260 
 
 19 
 
 293 
 
 43 
 
 316 
 
 67 
 
 261 
 
 20 
 
 294 
 
 44 
 
 317 
 
 68 
 
 263 
 
 21 
 
 295 
 
 45 
 
 318 
 
 69 
 
 265 
 
 22 
 
 296 
 
 46 
 
 319 
 
 70 
 
 267 23 
 
 297 
 
 47 
 
 3-^0 
 
 71 
 
 By the following Rule the quantity of steam required to 
 raise a given quantity of water to any given temperature 
 fs found.
 
 STEAM ENGINE. 379 
 
 RULE. Multiply the water to be warmed oy the differ- 
 ence of temperature between the cold water and that to 
 which it is to be raised, for a dividend ; then to the tempera- 
 ture of the steam add 900 degrees, and from that sum take 
 the required temperature of the water: this last remainder 
 being made a divisor to the above dividend, the quotient will 
 be '.he quantity of steam in the same terms as the water. 
 
 What quantity of steam at 212 will raise 100 gallons ol 
 water at 60 up" to 212? 
 X 100 
 
 7 all nS f 
 
 2 12o+9JO-2l2 
 steam. 
 
 Now, steam at the temperature of 212o is 1800 times its 
 bulk in water; or I cubic foot of fteam, when its elasticity 
 is equal to 3(J inches of mercury, contains 1 cubic inch of 
 water Therefore 17 gallons of water converted into steam, 
 occupies a space of 4l/9ii^ cubic feet, having a pressure 
 of 1& libs on the square inch. 
 
 In boiling by steam, using a jacket instead of blowing 
 the steam into the water, I believe, about 1U.5 square feet 
 of surface are allowed for each horse capacity of boiler 
 i. e. a 14 horse boiler will boil water in a pan set in a jacket, 
 exposing a surface of 10.5 X 14 = 147 square feet. 
 
 HORSEPOWER. Boulton and Watt suppose a horse able 
 to raise 32,OUO libs avoirdupois 1 foot high in a minute. 
 
 Desaguliers makes it 27,51)0 I'-bs. 
 Smeaton do. 22,916 do. 
 
 It is common in calculating the power of engines, to sup- 
 pose a horse to draw 2UO libs at the rate of 2 miles in an 
 hour, or 220 feet per minute, with a continuance, drawing 
 Ihe weight over a pulley now, 20U X 220:= 440UO, t. . 
 44000 libs at 1 foot per minute, or 1 lib at 44000 feet pel 
 minute. In the following Table 32,000 is used. 
 
 One horse power is equal to raise - gallons or 
 1'bs - feet high per minute.
 
 380 
 
 STEAM ENGINE. 
 
 Feet High 
 per lain. 
 
 Ale 
 
 Gallons. 
 
 Libs 
 Avnirdupoii. 
 
 Feet High 
 per min. 
 
 Ale 
 Gallons. 
 
 Lib* 
 
 Avoirdu, oia. 
 
 1 
 
 3123 
 
 32000 
 
 20 
 
 156 
 
 1600 
 
 2 
 
 1561^ 
 
 16000 
 
 25 
 
 125 
 
 120 
 
 3 
 
 1041 
 
 10666 
 
 30 
 
 104 
 
 1166 
 
 4 
 
 780 
 
 8000 
 
 35 
 
 89 
 
 914 
 
 5 
 
 624 
 
 6400 
 
 40 
 
 7S 
 
 800 
 
 6 
 
 520 
 
 5333 
 
 45 
 
 69 
 
 711 
 
 7 
 
 446 
 
 4571 
 
 50 
 
 62 
 
 640 
 
 8 
 
 390 
 
 4000 
 
 55 
 
 56 
 
 582 
 
 9 
 
 347 
 
 3555 
 
 60 
 
 52 
 
 533 
 
 10 
 
 312 
 
 3200 
 
 65 
 
 48 
 
 492 
 
 11 
 
 284 
 
 2909 
 
 70 
 
 44 
 
 457 
 
 12 
 
 260 
 
 2666 
 
 75 
 
 41 
 
 426 
 
 13 
 
 240 
 
 2461 
 
 80 
 
 39 
 
 400 
 
 14 
 
 223 
 
 2286 
 
 85 
 
 37 
 
 376 
 
 15 
 
 208 
 
 2133 
 
 90 
 
 34 
 
 355 
 
 16 
 
 195 
 
 20CO 
 
 95 
 
 32 
 
 337 
 
 17 
 
 183 
 
 1882 
 
 100 
 
 31 
 
 320 
 
 18 
 
 173 
 
 1777 
 
 110 
 
 28 
 
 291 
 
 19 
 
 164 
 
 1684 
 
 120 
 
 26 
 
 267 
 
 LENGTH OF STROKE. The stroke of an engine is 
 equal to one revolution of the crank shaft, therefore double 
 the length of the cylinder. When stating the length of 
 stroke, the length of cylinder is only given, that is, au en 
 gine with a 3 feet stroke, has its cylinder 3 feet long, be- 
 sides an allowance for the piston. 
 
 The following Table shows the length of stroke, (or 
 length of cylinder,) and the number of feet the piston tra- 
 vels in a minute, according to the number of strokes the 
 engine makes when working at maximum. 
 
 When calculating the power of engines, the feet per 
 minute are generally taken at 220.
 
 STEAM ENGINE. 
 
 381 
 
 JUmgth of 
 Stroke. 
 
 Number of 
 Strokes. 
 
 Feet p*r 
 minute. 
 
 Feet 2 
 
 43 
 
 172 
 
 3 
 
 32 
 
 192 
 
 4 
 
 25 
 
 2UO 
 
 5 
 
 21 
 
 210 
 
 6 
 
 19 
 
 228 
 
 7 
 
 17 
 
 238 
 
 8 
 
 15 
 
 240 
 
 -9 
 
 14 
 
 250 
 
 CYLINDER. When an engine in good ordei is perform- 
 ing its regular work, the effective pressure may be taken 
 at 8 libs on each square inch of the surface of the piston. 
 
 In a former edition the maximum effective pressure was 
 stated at 10 libs, but few engines are seldom or ever re- 
 quired to produce this work. 
 
 To calculate the paieer of an Engine. 
 
 RULE 1. Multiply the area of cylinder by the effective 
 pressure = say 8 libs, the product is the weight the engine 
 can raise. Multiply this weight by the number of feet the 
 piston travels in one minute, which will give the momentum, 
 6r weight, the engine can lift 1 foot high per minute ; divide 
 this momentum by a horse power, as previously stated, and 
 the quotient will be the number cf horse power the engine 
 is equal to. 
 
 RULE 2. 25 inches of the area of cylinder is equal to 
 one horse power, the velocity of the engine being conse- 
 quently 220 feet per minute. 
 
 EXAMPLE I. 
 
 What is the power of an engine, the cylinder being 42 
 inches diameter, and stroke 5 feet? 
 42 x.7854 X 10 X 210
 
 STEAM ENGINE. 
 
 EXAMPLE II. 
 
 What size of cylinder will a 60 horse power ei\ me n> 
 qi ire. when the stroke is 6 ieet ? 
 44'HJU X 60 
 
 = 1158 inches, area of cylinder. 
 
 228 X 10 
 
 Note. To find the power to lift a weight at any velocity, 
 multiply the weight in libs by the velocity in feet, and di- 
 vide by the horse power ; the quotient will be the number 
 of horse power required. 
 
 TABLE. 
 
 VVh-n the effec- 
 tive pressure on 
 cacti inch of 
 piston is 
 
 The area equal to 
 one horse power 
 Will be 
 
 53 libs. 
 
 3.7 inches. 
 
 48 
 
 4.17 
 
 43 
 
 4 65 
 
 38 
 
 5.26 
 
 33 
 
 6. (6 
 
 28 
 
 7.14 
 
 23 
 
 8.7 
 
 18 
 
 11.11 
 
 13 ' 
 
 15.46 
 
 8 
 
 25. 
 
 EXAMPLES calculated by Rule 2d, and by the above Table. 
 
 1st. What diameter is the cylinder of a 40 horse engine, 
 common pressure? 
 
 4U X 25 
 
 = 35.7, say 35^ inches diameter. 
 
 .7854 
 
 2d. What diameter is the cylinder of a 40 horse 
 gine, effective pressure 33 libs on the square inch ? 
 
 ^40 X 6 
 .7854 
 
 = 17.6, say 17f inches diameter.
 
 STEAM ENGINE. 383 
 
 3d. Thn cylinder of an engine is 40 inches diameter, 
 Rnd the effective pressure is 2u libs on the square men. 
 What is the power of the engine'? 
 
 Area of 40 = 1256.6 H- 10 = 125.6 horse power. 
 
 STEAM WAYS. The induction passages ought to be in 
 area one twenty fifth part of the area of cylinder. Say, if 
 area of cylinder be 25, the area of induction passage .should 
 be 1. The eduction pass.-ige ought to be a little more in 
 area than the induction, say one twenty-fourth part of the 
 area of cylinder, in place of one twenty-fifth. 
 
 Am PUMP. The cubic contents of the air pump is equai 
 to one-fourth of the cubic contents of cylinder, or when the 
 air pump is half the length of the stroke of the e-ngine, its 
 area is equal to half the area of cylinder. 
 
 CONDENSER is generally equal in capacity to the air 
 pump ; but when convenient it oucht to be more : for when 
 large, there is a greater space of vacuum, and the steam is 
 sooner condensed. 
 
 COLD WATER PUMP. The capacity of the cold water 
 pump depends upon the temperature of the water. Many 
 engines return their water, which cannot be so cold as water 
 newly drawn from a river, well, &c. ; but when water is at 
 the common temperature, each horse power requires nearly 
 7^- gallons per minute.* Taking this quantity as a standard, 
 the size of the pump is easily found by the following Kule, 
 viz. Multiply the number of horse power by 7-^ gallons, 
 and divide by the number of strokes per minute: this will 
 give the quantity of water to be raised each stroke of pump. 
 Multiply this quantity by'231, (the number of cubic inches 
 in a gallon,) and divide by the length of effective stroke of 
 pump, the quotient will be the area. 
 
 An engine will work with a less supply of water, say 5 gallons 
 per minute; hut when water can be had without a considerable 
 expense of power, 7J gallons is preferable ; because an abund* 
 ance of water keeps the condenser, &.c. cool, and thereby produce* 
 a better vacuum.
 
 3S4 STEAM ENGINE. 
 
 V EXAMPF.E. 
 
 What diameter of pump is requisite for a 20 horse power 
 steam engine, having a 3 feet stroke, the effective strokt 
 of pump to be 15 inches? 
 
 20 X 7o = 150 
 
 - = 4.6875 gallons the pump lifts each 
 
 stroke. 
 
 4.6875 X 231 
 
 15 
 
 = 72.1875 inches area of pump. 
 
 HOT WATER PUMP. The quantity of water raised at 
 each stroke ouuht to be equal in bulk to the 9UOth part oi 
 the capacity of the cylinder. 
 
 EXAMPLE I. 
 
 What quantity of feed water is necessary to supply the 
 boiler of a 10 horse engine, common pressure? 
 
 25 X 10 X 220 
 
 -- = 382 cubic feet of steam used, and 
 
 the water contained in 1 cubic foot of steam is 1 cubic 
 inch ; so that 382 cubic inches of water, or ! gallon, is 
 required per minute ; the pump, however, ought to be 
 made sufficiently large to supply 2 gallons per minute, to 
 make up tor any leakage or waste of steam. 
 
 EXAMPLE II. 
 
 What quantity of feed water is necessary to supply the 
 boiler of a 10 horse engine, the effective pressure 30 libs? 
 
 fi fi y 1 ^^ 2^0 
 
 -- - - = 101 cubic feet of steam equal to 10] 
 
 cubic inches, or -^ths nearly of a gallon of water. The 
 pump ought to supply f gallon per minute. 
 
 PROPORTIONS. The length of stroke being 1, the length
 
 STEAM ENGINE. 
 
 385 
 
 of beam to centre will be 2, the length of crank .5, and 
 the length of connecting rod 3. 
 
 The following Table shows the force which the con- 
 necting rod has to turn round the crank at different parts 
 of the motion. 
 
 Col. A. Decimal proportions of 
 descent of the piston, 
 the whole descent be- 
 ing 1. 
 
 Col. B. Angle between the con 
 nectingrod and crank. 
 
 Col. C. Effective itn^th of the 
 lever upon 'vhich the 
 connecting rod acts,the 
 whole crank being 1 
 
 Col. D. Decimal proportions of 
 half a revolution of the 
 fly-wheel. 
 
 Co/. C. Also shows the force 
 which is communicat- 
 ed to the fly-wheel, ex- 
 pressed in decimals, 
 the force of the piston 
 being 1. 
 
 A 
 
 B 
 
 C 
 
 D 
 
 .0 
 
 180 
 
 .0 
 
 .0 
 
 .05 
 
 151 
 
 .46 
 
 .128 
 
 .10 
 
 141 
 
 .62 
 
 .158 
 
 .15 
 
 131 
 
 .74 
 
 .228 
 
 .2 
 
 123^ 
 
 .830 
 
 .271 
 
 .25 
 
 117| 
 
 .892| .308 
 
 .3 
 
 110* 
 
 .94 
 
 .342 
 
 .35 
 
 104 
 
 .976 
 
 .377 
 
 .4 
 
 97i 
 
 .986 
 
 .41 
 
 .45 
 
 91f 
 
 1. 
 
 .441 
 
 .5 
 
 85^ 
 
 1. 
 
 .473 
 
 .55 
 
 80 
 
 .986 
 
 .507 
 
 .6 
 
 75 
 
 .958 
 
 .538 
 
 .65 
 
 69 
 
 .92 
 
 .572 
 
 .7 
 
 62 
 
 .88 
 
 .607 
 
 .75 
 
 57i 
 
 .824 
 
 .642 
 
 .8 
 
 49 
 
 .746 
 
 .68 
 
 .85 
 
 42 
 
 .66 
 
 .723 
 
 .9 
 
 34 
 
 .546 
 
 .776 
 
 .95 
 
 231 
 
 .390 
 
 .84 
 
 1.0 
 
 
 
 .000 
 
 1.0 
 
 FLY.WHEEL is used to regulate the motion of the en- 
 gine, and to bring the crank past its centres. The rule 
 for finding its weight, is, Multiplythe number of horses' 
 power of the engine by 2000, and divide by the square of 
 the velocity of the circumference of the wheel per second, 
 the quotient will be the weight in cwts. 
 
 Required the weight of a fly \vneel proper for an engine 
 33 Z
 
 386 STEAM ENGINE. 
 
 of 20 horse power, 18 feet diameter, and making 22 revo- 
 lutions per minute ? 
 
 18 feet diameter = 56 feet circumference, X 22 revob 
 tions per minute = 1232 feet, motion per minute -j- fiO =. 
 20 feet, motion per second ; then 20 2 = 420 the divisor. 
 20 horse power X 2000 = 40000 dividend, 
 40000 
 90 - 4 cwt - weight of wheel. 
 
 PARALLEL MOTION. The radius and parallel bars are 
 of the same dimensions ; their length being generally one- 
 fourth of the length of the beam between the two glands, 
 or one-half the distance between the fulcrum and gland. 
 Both pairs of straps are the same length between the cen- 
 tres, and which is generally three inches less than the half 
 of the length of stroke 
 
 GOVERN OR, or DOUBLE PENDULUM. If the revolutions 
 be the same, whatever be the length of the arms, the balls 
 will revolve in the same plane, and the distance of that 
 plane from the point of suspension, is equal to the length of 
 a pendulum, the vibrations of which will be double the revo- 
 lutions of the balls. For example ; suppose the distance 
 between the point of suspension and plane of revolution be 
 36 inches, the vibrations that a pendulum of 36 inches will 
 
 375 62 
 
 make per minute, is = - = 62 vibrations, and =31 
 V36 2 
 
 revolutions per minute the balls ought to make. 
 
 For the sake of variety in the steam engine, we shall 
 add the following table of the force and heat of steam. 
 Also, the power of steam engines, and the method of 
 computing it 
 
 The force of Steam and the heat of it. 
 
 At the temperature of 212 degrees of Fahrenheit's 
 Thermometer, the force of steam from water is just equal 
 to the pressure of the atmosphere ; but by increasing the 
 heat, effects will be obtained, which are detailed in the 
 following Table:
 
 STEAM ENGINE. 
 
 387 
 
 6 I .5.2 2 
 
 x !- 
 
 II 
 
 E 
 
 9 
 
 101 
 1l5 l 
 
 | 20 
 
 I 25 
 
 30 
 
 < J .5 
 
 40J 
 
 a 
 
 o-| ? 
 
 ! o- 
 
 230J 
 232^ 
 2351 
 237} 
 239.V 
 
 250; 
 
 259? 
 267" 
 273 I 
 278 | 
 
 I 282 J 
 
 
 
 ~ * 
 <I> 
 
 
 6 I 
 
 7 I 
 8 
 9 I 
 
 10 I 
 
 lis\ 
 
 
 
 25 
 
 g.2 
 
 2 o 
 
 = 1 
 
 S|SC 
 --^^ 
 
 i t o.^ 
 
 35 
 40 J 
 
 its 
 eq 
 
 By small additions to the temperature, an expansive 
 force may be given to steam, so as to be equal to 4UU times 
 its natural bulk, or in any other proportion, provided the 
 vessels, &c. that contain it be strong in proportion. 
 
 The Power of Steam Engines, and the Method of com- 
 puting it. 
 
 In computing the power of a steam engine, THREE 
 things must be duly observed. 1. The width or diame- 
 ter of the piston or cylinder. 2. The length of the stroke. 
 3. The strength of the steam. It is supposed" that the pis- 
 ton does, or ought to travel 220 feet per minute. 
 
 The power of an engine must vary according to the 
 strength of the steam ; and this must be the first point to 
 be decided. This pressure is fixed at different ratios by 
 different makers, varying from? to 12lbs. upon the square 
 inch. At Soho, they commonly fix it at 7 Ibs. and Smea- 
 ton only reckoned 7 Ibs. upon every circular inch. 
 
 Now the pressure being determined by the weight upon 
 the safety valve, here is the most correct of all methods 
 of ascertaining th power. 
 
 First. Find out how many hogsheads or pounds of 
 water the engine is capable of- raising ONE foot high in 
 ONE minute. 
 
 Secondly. Divide mat amount by the supposed ratios 
 or supposed power of a horse to raise water 1 foot high in 
 1 minute of time, and the quotient will give horse powers 
 of the engine.
 
 388 STEAM ENGINE. 
 
 RULR. 1. Find the area of the piston in square inches, 
 by squaring the diameter and multiplying the amount by 
 .7854, and the product will be the correct area. Or as the 
 decimal .78 is near to .75 or f ; for a ready calculation not 
 exactly correct, square the diameter and take f of that sum, 
 and that will be the area, nearly ; of the diameter of the 
 piston multiplied by its circumference, and that divided by 4 
 will give its area in square inches. 2. The area of the pis- 
 ton in square inches must show the number of square inches 
 exposed to the pressure of the steam ; now if we multiply 
 this area by the pressure upon every square inch, we shall 
 have the whole pressure upon the piston, or the weight 
 which the engine is capable of raising^ and if the piston 
 travel 220 feet per minute, that amount multiplied by 220 
 must give the weight of water that the engine is capable of 
 lifting 1 foot high in one minute. 3. Messrs. Boulton and 
 Watt suppose a horse able to raise 3200U Ibs. avoirdupois, 
 1 foot in a minute. Dr. Desaguliers makes it 2750U Ibs 
 Mr. Smeaton only 22916. Divide the number of Ibs. 
 *hat an engine of one horse power can raise 1 foot high 
 in 1 minute, and the quotient will give the horse powers. 
 
 What is the power of a steam engine, the cylinder of 
 which is 24 inches, which makes 22 double strokes in a 
 minute, each stroke being 5 feet long, and the force of the 
 Eteam equal to 12 Ibs. avoirdupois upon every square inch? 
 
 24 inches 452.4 square inches. 
 
 24 12 Ibs. per square inch. 
 
 96 5423.8 the whole pressure 
 
 upon the piston. 
 48 
 
 576 
 
 .7854 
 
 452.3904 area, nearly 452.4 square inches.
 
 WATER WHEEL. 389 
 
 The engine makes 22 double strokes, each 5 feet ii) a 
 oiinute = 220 feet, then 5428.8 Ibs. multiplied by 
 
 220 feet travelled per minute 
 
 will give 1 19436 Ibs. raised 1 foot high in 1 
 
 minute. 
 
 This divided by the standard of each engineer's calcula- 
 tion for a horse's power, and the quotients will give of 
 Boulton and Watt's 37 horse power. 
 
 Desagulier's 43 do. do. 
 
 Smeiitou's 52 do. do. 
 
 WATER WHEEL. 
 
 WATER. (Hydrostatics.) 
 
 Hydrostatics is the science which treats of the pressure, 
 or weight, and equilibrium of water, and other fluids, espe- 
 cially those that are non-elastic. 
 
 JVb/e 1. The pressure of water at any depth, is as its 
 depth ; for the pressure is as the weight, and the weight is 
 as the height. 
 
 Note 2. The pressure of water on a surface any how 
 immersed in it, either perpendicular, horizontal or oblique, 
 is equal to the weight of a column of water, the base being 
 tqual to the surface pressed, and the altitude equal to the 
 iepth of the centre of gravity, of the surface pressed, be- 
 low the top or surface of the fluid. 
 
 PROBLEM I. 
 
 In a vessel filled with water, the sides of which are up 
 right and parallel to each other, having the top of the same 
 dimensions as the bottom, the pressure exerted against the 
 bottom, will be equal to the area of the bottom multiplied 
 by the dep'h of water. 
 33*
 
 WATER WHEEL. 
 
 A vessel 3 feet square and 7 feet deep, is filled with wa 
 ter; what pressure does the bottom support? 
 
 3 2 X 7 X 1000 
 
 = 3937 libs avoirdupois. 
 
 PROBLEM II. 
 
 A side of any vessel sustains a pressure equal to tne area 
 of the side multiplied by half the depth, therefore the siiies 
 and bottom of a cubical vessel sustains a pressure equal to 
 three times the weight of water in the vessel. 
 
 EXAMPLE I. 
 
 The gate of a sluice is 12 feet deep and 20 feet broad; 
 what is the pressure of water against it ? 
 20 X 12 X 6 X 1000 
 = 90000 = 40J- tons nearly. 
 
 From ./Vote 2d. The pressure exerted upon the side of 
 a vessel, of whatever shape it may be, is as the area of the 
 side and centre of gravity below the surface of water. 
 
 EXAMPLE II. 
 
 What pressure will a board sustain, placed diagonally 
 through a vessel, the side of which is 9 feet deep, and 
 bottom 1 2 feet by 9 feet ? 
 V 12* -f- 9* = 15 feet, the length of diagonal board. 
 
 15 X 9 X 44- X 1000 
 
 j = 37969 libs nearly. 
 
 16 
 
 Though the diagonal board bisects the vessel, yet it sus- 
 tains more than the half of the pressure in the bottom, for 
 the area of bottom is 12 X 9, and the half of the pressure 
 is half 60759 = 30375. 
 
 The bottom of a conical or pyramidical vessel sustains a 
 pressure equal to the area of the bottom and depth of water, 
 consequently, the excess of pressure is three times the 
 Weight of water in the vessel.
 
 WATER WHEEL. 391 
 
 WATER. (Hydraulics.) 
 
 Hydraulics is that science which treats of fluids consider* 
 ed as in motion, it therefore embraces the phenomena exhi- 
 bited by water issuing from orifices in reservoirs, projected 
 obliquely, or perpendicularly, in Jet-d'eaux, moving in 
 pipes, canals, and rivers, oscillating in waves, or oppos- 
 ing a resistance to the progress of solid bodies. 
 
 It would bo needless here to go into the minutiae of hy- 
 draulics, particularly when the theory and practice do not 
 agree. It is only the general laws, deduced from experi- 
 ment, that can be safely employed in the various opera- 
 tions of hydraulic architecture. 
 
 Mr. Banks, in his Treatise on Mills, after enumerating 
 a number of experiments on the velocity of flowing water, 
 by several philosophers, as well as his. own, takes from 
 thence the following simple rule, which is as near the 
 truth as any that have been stated by other experimentalists. 
 
 RULE. Measure the depth (of a vessel, &c.) in feet, 
 extract the square root of that depth, and multiply it by 5.4, 
 which gives the velocity in feet per second; this mul- 
 tiplit d by the area of the orifice in feet, gives the number 
 of cubic feet which flows out in one second. 
 
 Let a sluice be 10 feet below the surface of the water, 
 its length 4 feet, and open 7 inches; required the quanti- 
 ty of water expended in one second ? 
 
 V10 = 3.162 X 5-4 = 17.0748 feet velocity. 
 
 4X7 
 
 : = 2| feet X 17.0748 = 39.84 cubic feet of 
 
 water per second. 
 
 If the area of the orifice is great compared with the 
 head, take the medium depth, and two-thirds of the velo- 
 city from th;xt depth, for the velocity. 
 
 Civen the perpendicular depth of the orifice 2 feet, ita 
 horizontal length 4 feet, and its top 1 foot below the sur- 
 face of water. To Snd the quantity discharged in one 
 second :
 
 392 WATER WHEEL. 
 
 The medium deptn is =. 1.5 X 5.4 = 8.10 j = 
 5.40 X 3 = 43.20 cubic feet.* 
 
 The quantity of water discharged through slits, or notches, 
 cut in the side of a vessel or dam, and opeu at the top, wiL" 
 be found by multiplying the velocity at the bottom by the 
 depth, and taking f of the product for the area; which 
 again multiplied by the breadth of the slit, or notch, gives 
 the quantity of cubic feet discharged in a given time. 
 
 Let the depth be 5 inches, and the breadth 6 inches ; re- 
 quired the quantity run out in 40 seconds 1 
 
 The depth is .4166 of a foot. 
 The breadth is .5 of a foot. 
 
 V .4166 = .6455 X 5-4 X f = 2.3238 X .4166 = 
 96825 X -5 = .48412 feet per second. 
 
 Then .484 12 X 46. = 22.269 cubic feet in 46 seconds. 
 
 There are two kinds of water wheels, undershot and 
 overshot. Undershot when the water strikes the whee< at 
 or below the centre. Overshot, when the water falls upon 
 the wheel above the centre. 
 
 The effect produced by an undershot wheel, is from the 
 impetus of the water. The effect produced by an overshot 
 wheel, is from the gravity or weight of the water. 
 
 Of an undershot wheel the power is to the effect as 3 : 1. 
 Of an overshot wheel, the power is to the effect as 3 : 2 
 which is double the effect of an undershot wheel. 
 
 The square root of the depth is not taken in this example, b it when 
 the depth la considerable, 't ought to be taken.
 
 WATER WHEEL. 393 
 
 The following is on Abridgment of SMEATON on WAIER WHirta, 
 UNDERSHOT. 
 
 Velocity of water in 1" =V 
 Weight of 1 cub. in. of water = W 
 Area of sluice =A 
 
 Quantity of water =Q, 
 
 Power of the water to ) 
 
 produce mechanical } =P mechanical effect 
 
 effect ^ 
 
 POWER AND EFFECT OF MAXIMUM. 
 
 V. A.= d in one second. 
 
 a\V.V = P ; Power to product 
 
 Velocity of wheel in 1" = v 
 
 Effective velocity of water = E v _ _ v P : e : s 10 : 3.62, 
 
 Effect produced by the ) or 3 : 1 
 
 wheel 5 V : v : : 40 : 3.5, 
 
 Weight raised = to W1 or 5 : 2. 
 
 Velocity of weight raised = i> 
 
 OVERSHOT. 
 
 Descent of water including head \ _-r\ || 
 and diameter of wheel* J ~ n w p 
 
 The weight of water expended t , 
 in one second j U 
 
 POWER AND EFFECT AT MAXIMUM. 
 
 Power of the water is = D.WJjP : e : : 10 : 6.6, or 3 : 2 nearly. 
 Effect of the wheel is = wv = 41 Double that of an undershot 
 
 The velocity of maximum is = 3 feet in one second. 
 
 Since the effect of the overshot is double that of the un- 
 dershot, it follows that the higher the wheel is in proportion 
 to the whole descent, the greater will be the effect. 
 
 The maximum load for an overshot wheel, is that which 
 reduces the circumference of the wheel to its proper velo- 
 city, 3 feet in 1 second ; and this will be knowu, by di- 
 viding the effect it ought to produce in a given time, by the 
 space intended to be described by the circumference of the 
 
 r * By Head IB understood the distance between the orifice and the part of th 
 wheel on which the water faJls. The fall is the perpendicular height from the 
 tottotn of the wheel to the orifice
 
 394 WATER WHEEL. 
 
 wheel in the same time; the quotient will be the .resistance 
 overcome at the circumference of the wheel, and is equal 
 to the load required, the friction and resistance of the ma- 
 chinery included. 
 The following is an extract from Banks on Mills, p. 152. 
 
 " The effect produced by a given stream in falling 
 through a given space, if compared with a weight, will be 
 directly as that space ; but if we measure it by the velo- 
 city communicated to the wheel, it will be as the square 
 root of the space descended through, agreeably to the laws 
 of falling bodies. 
 
 " Experiment 1. A given stream is applied to a wheel 
 at the centre ; the revolutions per minute are 38.5 
 
 " Ex. 2. The same stream applied at the top, turns the 
 same wheel 57 times in a minute. 
 
 " If in the first experiment the fall is called 1, in the se- 
 cond it will be 2 : then VI : V2 : : 38.5 : 54.4, which are 
 in the same ratio as the square roots of the spaces fallen 
 through, and near the observed velocity. 
 
 " In the following experiments a fly is connected with 
 the water wheel. 
 
 Ex. 3. The water is applied at the centre, the wheel 
 revolves 13.03 times in one minute. 
 
 " Ex. 4. The water is applied at the vertex of the wheel, 
 and it revolves 18.2 times per minute. 
 
 As 13.03 : 18.2 : : VI : V2 nearly. 
 
 " From the above we infer, that the circumferences of 
 wheels of different sizes may move with velocities which are 
 as the square roots of their diameters without disadvantage, 
 compared one with another, the water in all being applied 
 at the top of the wheel ; for the velocity of falling water at 
 the bottom or end of the fall is as the time, or as the square 
 root of the space fallen through ; for example, let the fall 
 be 4 feet, then, As VI 6 : I" : : V4 : ", the time of falling 
 through 4 feet : Again, let the fall he 9 feet, then, VI 6^ 
 1" : : V9 : ^", and so for any other space, as in the follow- 
 ing Table, where it appears that water will fall through one 
 foot in a quarter of a second, through 4 feet in half a se- 
 cond, through 9 feet in 3 quarters of a second, and through 
 16 feet in one s^coud. And if a wheel 4 feet in diameter
 
 WATER WHEEL. 395 
 
 moved as fast as the water, it could not revolve in leas than 
 1.5 second, neither could a wheel of 16 feet diameter re- 
 volve in less than three seconds ; but though it is impossible 
 for a wheel to move as fast as the stream which turns it, yet, 
 if their velocities bear the same ratio to the time of the fall 
 through their diameters, the wheel 16 feet in^diamcter 
 may move twice as fast as the wheel 4 feet diammer." 
 
 TABLE. 
 
 Height 
 of the fall in 
 feet. 
 
 Time of 
 falling in 
 seconds. 
 
 Height 
 of the tall in 
 feet 
 
 Time of 
 fallina in 
 second* 
 
 1 
 
 .25 
 
 14 
 
 .935 
 
 2 
 
 .352 
 
 16 
 
 1. 
 
 3 
 
 .432 
 
 20 
 
 1.117 
 
 4 
 
 .5 
 
 24 
 
 1.22 
 
 5 
 
 .557 
 
 25 
 
 1.25 
 
 6 
 
 .612 
 
 30 
 
 1.37 
 
 7 
 
 .666 
 
 36 
 
 1.5 
 
 8 
 
 .706 
 
 40 
 
 1.58 
 
 9 
 
 .75 
 
 45 
 
 1.67 
 
 10 
 
 .79 
 
 50 
 
 1.76 
 
 12 
 
 .864 
 
 
 
 POWER AND EFFECT. The power water has to produce 
 mechanical effect, is as the quantity and fall of perpendi- 
 cular height. The mechanical effect of a wheel is as the 
 quantity of water in the buckets and the velocity. 
 
 The power is to the effect as 3 : 2, that is, suppose the 
 
 9000 X 2 18000 
 
 power to be 9000, the effect will be = 
 
 3 
 
 = 6000. 
 
 HEIGHT op THE WHEEL. The higher the wheel is in 
 proportion to the fall, the greater will be the effect, because 
 it depends less upon the impulse, and more upon the gra- 
 vity of the water ; however, the head should be such, that 
 the water will have a greater velocity than the circumfer- 
 ence of the wheel : and the velocity that the circumference
 
 396 WATER WHEEL. 
 
 oi the wheel ought to have, being known, the head required 
 to give the water its proper velocity, caii easily b'e known 
 from the rules of Hydrostatics. 
 
 VELOCITY OF THE WHEEL. Banks, in the foregoing 
 quotation, says, " That the circumferences of overshot 
 wheels 9 different sizes may move with velocities as the 
 square roots of their diameters, without disadvantage." 
 Smeaton says, " Experience confirms that the velocity 
 of 3 feet per second is applicable to the highest overshot 
 wheels, as well as the lowest ; though high wheels may 
 deviate further from this rule, before they will lose their 
 power, by a given aliquot part of the whole, than low ones 
 can be admitted to do ; for a 24 feet wheel may move at 
 the rate of 6 feet per second, without losing any consider 
 able part of its power.." 
 
 It is evident that the velocities of wheels, will be in pro- 
 portion to the quantity of water and the resistance to be 
 overcome : if the water flows slowly upon the wheel, 
 more time is required to fill the buckets than if the water 
 flowed rapidly ; and whether Smeaton or Banks is taken 
 as a data, the mill-wright can easily calculate the size of 
 his wheel, when the velocity and quantity of water in a 
 given time is known. 
 
 EXAMPLE I. 
 
 What power is a stream of water equal to, of the follow- 
 ing dimensions, viz. 12 inches deep, 22 "Inches broad; 
 velocity 7U feet in llf seconds, and fall 60 feet ? Also, 
 what size of a wheel could be applied to this fall ? 
 12 X 22 
 - =1.83 square feet : area of stream. 
 
 llf : 70 : : 60" : 357.5 lineal feet per min. velocity. 
 357.5 X 1-83 = 654.225 cubic feet per iinute. 
 654.225 x 62.5 = 40889.0625 avoir, libs per minute. 
 40889.0625 X 60 = 2453343.7500 momentum at a fall of 
 
 60 feet 
 2453343.7500 
 
 44000 =6^7 horse power. 
 
 8:2:: 55.7 : 37.13 effective power.
 
 WATER WHEEL. 397 
 
 The diameter of a wheel applicable to this fall, will be 
 63 feet, allowing one foot below for the water to escape, 
 and one foot above for its free admission. 
 58 X 3.1416 = 182.2128 circumference of wheel. 
 60 X 6 = 360 feet per minute, = velocity of wheel. 
 654.225 
 =1.8 sectional area of buckets. 
 
 doO 
 
 The buckets must only be half full, therefore 1.8 X 2 = 
 3.6 will be the area. 
 
 To give sufficient room for the water to fill the backets, 
 
 3.6 
 the wheel requires to be four feet broad, now = .9, say 
 
 1 foot depth of shrouding. 
 
 360 
 
 ; = 1.9 revolutions per minute the wheel will 
 1B'<3.2 128 
 
 make. 
 
 Power of water = 55.7 H. p. "| 
 
 Effective power of do. = 37.13 H. P. 
 Dimensions C Diameter = 58 feet. \-Jlns. 
 
 of } Breadth = 4 feet. I 
 
 wheel. ( Depth of shrouding = 1 foot. J 
 
 EXAMPLE II. 
 
 What is the power of a water wheel, 16 feet diameter, 
 12 feet wide, and shrouding 15 inches deep 1 
 16 X 3.1416 = 50.2656 circumference of wheel. 
 12 x H = 15 square feet, sectional area of buckets. 
 60x4 = 240 lineal feet per minute, = velocity. " 
 240 X 15 = 3600 cubic feet water, when buckets are full ; 
 
 when half full, 1800 cubic feet. 
 
 1800 x 62.5 =112500 avoir, libs of water per minute. 
 1 12500 X 16 = 1800000 momentum falling 16 feet. 
 
 1200000 
 3:2:: 1800000 : = 27 horse power. 
 
 BUCKETS. The number of buckets toa wheel should be 
 as few as possible, to retain the greatest quantity of water ; 
 and their mouths only such a width as to admit the requisite 
 34
 
 398 WATER WHEEL. 
 
 quantity of water, and at the same time sufficient rocrn to 
 allow the air to escuo*. 
 
 THE COMMUNICATION OF POWER. There are no pnmo 
 movers of machinery from which power is taken in agreater 
 variety of forms than the water wheel, aud among such a 
 number there cannot fail to be many bad applications. 
 
 Suffice it here to mention one of the worst, aud mostge 
 nerally adopted. For driving a cotton mill in this neigh, 
 bourhood, there is a water wlieel about 12 feet broad, and 
 20 feet diameter : there is a division in the middle of the 
 buckets upon which the segments are bolted round the 
 wheel, and the power is taken from the vertex : from this 
 erroneous application, a great part of tne power is lost ; for 
 the weight ot water upon the wheel presses against the axle 
 in proportion to the resistance it has to overcome, and if the 
 axle was uot a large mass of wood, with very strong iron 
 journals, it could not stand the great strain which is upon it. 
 
 The most advantageous part of the wheel, from which 
 the power can be taken, is that point in the circle of gyra- 
 tion horizontal to the centre of the axle : because, taking 
 the po \er from this part, the whole weight of water in the 
 bucKets acts upon tne teeth of the wheels : aud the axle 
 of tne water wheel suners no strain. 
 
 The proper connexion of machinery to water wheels is 
 of tne first importance, and mismanagement in this parti- 
 cular point is often the cause of the journals and axles 
 giving way, besides a considerable loss or'nowrr. 
 
 To find the radius of the circle of gyration in a water 
 wheel is therefore oi advantage to the saving of power, 
 and the following example will show the rule by which it 
 is found. See Centre of Gyration. 
 
 Required the radius of the circle of gyration in a water 
 wheel, 30 feet diameter ; the weight of the arms being 12 
 tons, shrouding 20 tons, and water 15 tons.
 
 PUMPS. 399 
 
 30 feet diameter, radius = 15 feet 
 
 S 2U x 15 2 = 45UU X 2 = 9UUO j The opposite side ol 
 A 12 X 15* (the water wheel 
 
 900 X 2=1SOOJ mu st be taken. 
 
 W 15 x 15 a = 3375 = 3375 
 2 X 20 + 12 = 64 
 
 W 15 
 
 14175 
 
 = 179, the square root 
 
 79 79 
 
 of which is 13 -fa feet, the radius of the circle of gyration. 
 
 PUMPS. 
 
 There are two kinds of pumps, lifting and forcing. The 
 lifting, or common pumps, are applied to wells, &c., where 
 the depth does not exceed 32 feet ; for beyond this depth 
 they cannot act, because the height that water is forced up 
 into a vacuum, by the pressure of the atmosphere, is about 
 34 feet. 
 
 The force pumps are those that are used on all other oc- 
 casions, and can raise water to any required height. 
 Bramah's celebrated pump is one of this description, and 
 shows the amazing power that can be produced by such 
 application, and which arises from the fluid and non-com- 
 pressible qualities of water. 
 
 The power required to raise water any height is equal 
 to the quantity of water discharged in a given time, and 
 the perpendicular height. 
 
 Required the power necessary to discharge 175 ale gal 
 Ions of water per minute, from a pipe 252 feet high { 
 
 One ale gallon of water weighs 10-J- libs avoir, nearly. 
 175 X 10| = 1799 X 252 = 453348 
 
 ir.s horse power
 
 400 PUMPS. 
 
 The following is a very simple Rule, and easily kept in 
 remembrance. 
 
 Square the diameter of the pipe in inches, and the pro 
 duct will be the number of libs of water avoirdupois con- 
 tained in every yard length of the pipe. If the last figure 
 of the product be cut off, or considered a decimal, the re- 
 maining figures will give the number of ale gallons in each 
 yard of pipe ; and if the product contains only one figure, 
 it will be tenths of an ale gallon. The number of ale 
 gallons multiplied by 282, gives the cubic inches in each 
 yard of pipe, and the contents of a pipe may be found by 
 Proportion 
 
 EXAMPLE. 
 
 What quantity of water will be discharged from a pipe 
 5 inches diameter, 252 feet perpendicular height, the water 
 flowing at the rate of 210 feet per minute? 
 
 210 
 5* X -5- = 175 ale gallons per minute. 
 
 A o 
 
 252 
 5 2 X z- = 2100 libs water in pipe. 
 
 p 
 
 2100x210 
 
 =10 horse power required to pump that quan- 
 tity of water. 
 
 The following Table gives the contents of a pipe one 
 inch diameter, in weight and measure, which serves as a 
 standard for pipes of other diameters, their contents being 
 found by the following rule. 
 
 Multiply the numbers in the following Table against 
 any height, by the square of the diameter of the pipe, and 
 the product will be the number of cubic inches avoirdu- 
 pois ounces, and wine gallons of water, that the given pipe 
 will contain. 
 
 How many wine gallons of water is contained in 
 pipe 6 inches diameter, and 60 feet long ? 
 
 2.448U X 36 = 88.1280 wine gallons. 
 In a wine gallon there are 231 cubic inches.
 
 PUMPS. 
 
 401 
 
 TABLE. 
 
 ONE INCH DIAUE.TER. 
 
 ft** 
 
 high. 
 
 Quantity in 
 cubic inches. 
 
 Weight in 
 avoir, oz. 
 
 Gallons 
 wine measure. 
 
 1 
 2 
 3 
 4 
 5 
 
 9.42 
 
 18.85 
 28.27 
 37.70 
 47.12 
 
 5.46 
 10.92 
 16.38 
 21.85 
 27.31 
 
 .0407 
 .0816 
 .1224 
 .1632 
 .2040 
 
 6 
 
 7 
 8 
 9 
 10 
 
 56.55 
 65.97 
 75.40 
 84.82 
 94.25 
 
 32.77 
 38.23 
 43.69 
 49.16 
 54.62 
 
 .2448 
 .2423 
 .3264 
 .3671 
 .4080 
 
 20 
 30 
 
 40 
 50 
 60 
 
 188.49 
 282.74 
 376.99 
 471.24 
 565.49 
 
 109.24 
 163.86 
 218.47 
 273.09 
 327.71 
 
 .8160 
 1.2240 
 1.6300 
 
 2.0400 
 2.4480 
 
 70 
 80 
 90 
 100 
 200 
 
 659.73 
 753.98 
 848.23 
 942.48 
 1884.96 
 
 382.33 
 436.95 
 491.57 
 546.19 
 
 1092.38 
 
 2.8560 
 3.2640 
 3.6700 
 4.0800 
 8.1600 
 
 The resistance arising from the friction of water flowing 
 through pipes, &c. is directly as the velocity of the water, 
 and inversely as the circumference of the pipe. 
 
 The data given is a medium, and which is l-5th of the 
 whole resistance ; this is the standard generally adopted, 
 being considered as most correct. 
 
 EXAMPLE I. 
 
 What is the power requisite to overcome the resistance 
 and friction of a column of water 4 inches diameter, 100 
 feet high, and flowing at the velocity of 300 feet per mi. 
 uute? 
 
 34* 2 A
 
 402 PUMPS. 
 
 5!!dl2< = 546.19, sa, 546 ,. 
 16 
 
 5^6.2_X_300 ^ there{bre 
 
 440UU 
 
 power required to overcome the resistance occasioned by 
 the weight and friction of the water will be 3.7 -J- .7 = 4.4 
 H. P., say 4.5 horse power, 
 
 EXAMPLE II. 
 
 There is a cistern 20 feet square, and 10 feet deep, 
 placed on the top of a tower 6U feet high ; what power \ 
 requisite to hi) this cisteru in 30 minutes, and what will 
 be the diameter of the pump, when the length of stroke is 
 2 feet, and making 40 per minute ? 
 20 x 20 x 10 = 4000 cubic contents of cistern. 
 
 =133.3 cubic feet of water per minute. 
 oO 
 
 133.3 X 1000 
 
 - - -- = 8331.25 libs avoir, per mmute. 
 
 6331.25 x 60 
 
 - 44(Fo = 11-36 h rse power 
 
 = 2.27 -f- 11.11 = 13.63 horse power required. 
 133.3 
 
 j/ 31 1.7 =*= 17.6 inches diameter of pump required. 
 
 Founders generally prove the pipes they cast to stand a 
 certain pressure, which is calculated by the weight of a per- 
 pendicular column of water, the area being equal to the 
 area of the pipe, and the height equal to any given height. 
 
 To ascertain the exact pressure of water to which a pipe 
 is subjected, a safety valve is used, generally of 1 inch 
 diameter, and loaded with a weight equal to the pressure 
 required : for example, a pipe requires to stand a pressure 
 of 300 feet, what weight will be required to load the safe. 
 ty valve 1 inch diameter? 
 
 Feel. liicnee. Ounce* 
 
 aOU X 12 = 36,00 X *7854 =2827.4400 X 1000 
 
 l(;2 libs 4i oz. weight reauired.
 
 PUMPS. 40b 
 
 Each of the weifhts for the safety valves of these Hy- 
 drostatic proving machines are generally made equal to a 
 pressure of a column of water 50 feet high, the area beiug 
 the area of the valve. 
 
 50 feet of pressure on a valve 1 inch diam. = 17.06 libs. 
 50 do. do. do. 1| do. = 26.65 do. 
 
 60 do. do. do. 1 do. = XS.3S do. 
 
 50 do. do. do. 2 do. = 68.24 do. 
 
 In pumping, there is always a deficiency owing to the 
 tscape of water through the valves; to account for this 
 oss, there is an allowance of 3 inches for each stroke oi 
 ;iston rod : for example, a 3 feet stroke may be calcula- 
 ted at 2 feet 9 inches. 
 
 There is a town, the inhabitants of which amount to 
 12000, and it is proposed to supply it with water, from a 
 river running through the low grounds 250 perpendicular 
 feet below the best situation from the reservoir. 
 
 It is required to know the power of an engine capable 
 of lifting a sufficient quantity of water, the daily supply 
 being calculated at 10 ale gallons to each individual; 
 also, what size of pump and pipes are requisite for such 1 
 
 12000 X 10 = 120000 gallons per day. 
 
 120000 
 Engine is to work 12 hours, = 10000 gallons per 
 
 hour. 
 
 10000 
 
 - = 166.6 gallons per minute. 
 
 The pump to have an effective stroke of 3^ feet, and 
 making 30 strokes per minute. 
 166.6 
 
 : = 5.5533 gallons each stroke. 
 
 oO 
 
 282 X 5.6 = 1579.2 cubic inches of water each stroke. 
 
 1579.2 
 
 : = 35.1 inches, area of pump. 
 
 3 feet 9 in. = 45 in, 
 
 35 1 
 ^ = 44.7, therefore V 44-7 = 6. 7 diam. of pump.
 
 404 FUMPS. 
 
 The pipes will require to be at leaft the diameter of the 
 pump ; if they are a little more, the water will not require 
 to flow so quickly through them, and thereby cause less 
 riction. 
 
 The power of the engine will be 
 
 16C.6 gal. X 10-J- Ib. X 250 feet = 426925 momentum 
 426925 
 = 9.7, add l-5th = 11.64 horse power. 
 
 : 13.3, = 15.96 do. Watt. 
 
 426925 
 
 -^5oo = 16 ' 5 ' ' = 18 ' 6 d * Desa ? ulieri 
 
 426925 
 
 229 1C 
 
 18.6 = ?2 32 do. Smeaton.
 
 MILL WORK. 
 
 405 
 
 This table is inserted from Ferguson's Mechanical Lectures. 
 The speed is calculated for a millstone six feet diameter; but as mill- 
 stones in general use are seldom more than four feet six inches 
 diameter, the speed must be increased accordingly ; and it is found by 
 experience, that millstones of this size will work well when making 
 120 revolutions per minute. Such a mill as this, with a water wheel 
 18 feet diameter, and a fall of water about 7 feet, will require about 
 32 hogsheads every minute to turn the wheel with the third part of 
 the velocity with which the water falls, and to overcome the resistance 
 arising from the friction of gears and attrition of the stones in grinding 
 the corn. 
 
 H< ight 
 of the 
 fall of 
 water. 
 
 Velocity 
 of the 
 water per 
 second. 
 
 Velocity 
 of the 
 wheel per 
 second. 
 
 Revolu- 
 tions o< 
 he wheel 
 per 
 minute. 
 
 Revolu- 
 tions of 
 
 stone for 
 one of the 
 wheels. 
 
 Cogs in the 
 wheel and 
 staves in the 
 trundle. 
 
 Revolu- 
 tions of 
 the mill 
 stone pe 
 
 minute. 
 
 Feet. 
 
 Feet and 
 lundredth 
 parts of a 
 foot. 
 
 Feet and 
 hundredth 
 
 Revolu- 
 tions and 
 hundredth 
 
 Revolu- 
 tions and 
 undredth 
 parts of a 
 revolu- 
 tion. 
 
 Cogs. 
 
 Staves. 
 
 Revolu- 
 tions and 
 hundredth 
 parts of a 
 revolu- 
 tion. 
 
 foot. 
 
 revolu- 
 tion. 
 
 1 
 
 8 02 
 
 2.67 
 
 2.83 
 
 21 20 
 
 127 
 
 6 
 
 59.92 
 
 2 
 
 11.34 
 
 3.78 
 
 4.00 
 
 15.00 
 
 105 
 
 7 
 
 60.00 
 
 3 
 
 13.89 
 
 4.63 
 
 4.91 
 
 12.22 
 
 98 
 
 8 
 
 60.14 
 
 4 
 
 16.04 
 
 5.35 
 
 5.67 
 
 10.58 
 
 95 
 
 9 
 
 59.87 
 
 5 
 
 17.93 
 
 5.98 
 
 6,34 
 
 9.46 
 
 85 
 
 9 
 
 59.84 
 
 6 
 
 19.64 
 
 6.55 
 
 6.94 
 
 8.64 
 
 78 
 
 9 
 
 60.10 
 
 7 
 
 21.21 
 
 7.07 
 
 7.50 
 
 8.00 
 
 72 
 
 9 
 
 60.00 
 
 8 
 
 22.68 
 
 7.56 
 
 8.02 
 
 7.48 
 
 71 
 
 9 
 
 59.67 
 
 9 
 
 24.05 
 
 8.02 
 
 8.51 
 
 7.05 
 
 70 
 
 10 
 
 59.57 
 
 10 
 
 25.35 
 
 8.45 
 
 8.97 
 
 6.69 
 
 67 
 
 10 
 
 60.09 
 
 11 
 
 26.59 
 
 8.86 
 
 9.40 
 
 6.38 
 
 64 
 
 10 
 
 6U.16 
 
 12 
 
 28.77 
 
 9.26 
 
 9.82 
 
 6.11 
 
 61 
 
 10 
 
 59.90 
 
 13 
 
 28.91 
 
 9.64 
 
 10.22 
 
 5.87 
 
 59 
 
 10 
 
 60.18 
 
 14 
 
 30.00 
 
 10.00 
 
 10.60 
 
 5.66 
 
 56 
 
 10 
 
 59.36 
 
 15 
 
 31.05 
 
 10.35 
 
 10.99 
 
 5.46 
 
 55 
 
 10 
 
 60.48 
 
 16 
 
 32.07 
 
 10.69 
 
 11.34 
 
 5.29 
 
 53 
 
 10 
 
 60.10 
 
 17 
 
 33.06 
 
 11.02 
 
 11.70 
 
 5.13 
 
 51 
 
 10 
 
 59.67 
 
 18 
 
 34.02 
 
 11.34 
 
 12.02 
 
 4.99 
 
 50 
 
 10 
 
 60.10 
 
 19 
 
 34.95 
 
 11.65 
 
 12.37 
 
 4.85 
 
 48 
 
 10 
 
 60.61 
 
 20 
 
 35.86 
 
 11.95 
 
 12.68 
 
 4.73 
 
 47 
 
 10 
 
 59.59
 
 406 
 
 MILL WORK. 
 
 TABLE showing the Relative Power of Overshot Whcclt 
 Steam Engines, Horses, Men, and Windmills oj differ 
 rent kinds, by Fenwick. 
 
 umber or ale gallons deli- 
 vered on overshot wheel 
 10 feet in diameter, every 
 minute. 
 
 iainrii r of the cylinder in 
 the common steam engine, 
 in inches. 
 
 iameterof the cylinder in 
 the improved steam en- 
 gine, in inches. 
 
 12 hours per day, and 
 moving at the rate of two 
 miles per hour. 
 
 umber of men, working 12 
 hours nduy. 
 
 ml ins of Dutch sails In 
 their common position, in 
 feet. 
 
 adius of Dutch sails in 
 their best position, in feet. 
 
 adius of Mr. Smeaton's en- 
 larged sails, .11 feet. 
 
 eight to wl-ich lire.- di He- 
 rent powers wil. raise 11 MM) 
 UK. avoirdupois in a mi- 
 nute. 
 
 Q 
 
 a 
 
 Q 
 
 z; 
 
 2 
 
 M 
 
 
 
 a 
 
 
 230 
 
 8. 
 
 6.12 
 
 1 
 
 5 
 
 21.24 
 
 17.89 
 
 15.65 
 
 13 
 
 390 
 
 9.5 
 
 7.8 
 
 2 
 
 10 
 
 30.04 
 
 25.20 
 
 22.13 
 
 26 
 
 528 
 
 10.5 
 
 8.2 
 
 3 
 
 15 
 
 36.80 
 
 30.98 
 
 27.11 
 
 39 ' 
 
 660 
 
 11.5 
 
 8.8 
 
 4 
 
 20 
 
 42.48 
 
 35-78 
 
 31.30 
 
 52 
 
 720 
 
 12.5 
 
 9.3 
 
 5 
 
 25 
 
 47.50 
 
 40.00 
 
 35.00 
 
 65 
 
 970 
 
 14. 
 
 10.55 
 
 6 
 
 30 
 
 52.03 
 
 43.82 
 
 38.34 
 
 78 
 
 1170 
 
 15.4 
 
 11.75 
 
 7 
 
 35 
 
 56.90 
 
 47.33 
 
 41.44 
 
 90 
 
 1350 
 
 16.8 
 
 12.8 
 
 8 
 
 40 
 
 60.09 
 
 50.60 
 
 4427 
 
 104 
 
 1455 
 
 17.3 
 
 13.6 
 
 9 
 
 45 
 
 63-73 
 
 53.66 
 
 46.96 
 
 117 
 
 1584 
 
 18.5 
 
 14.2 
 
 10 
 
 50 
 
 67-17 
 
 56.57 
 
 4^.50 
 
 130 
 
 1740 
 
 19.4 
 
 14.8 
 
 11 
 
 55 
 
 70.46 
 
 59.33 
 
 51.91 
 
 143 
 
 lyoo 
 
 20.2 
 
 15.2 
 
 12 
 
 60 
 
 73.59 
 
 61.97 
 
 54.22 
 
 156 
 
 2100 
 
 21. 
 
 16.2 
 
 13 
 
 65 
 
 76.59 
 
 64.5 
 
 56.43 
 
 169 
 
 2300 
 
 22. 
 
 17. 
 
 14 
 
 70 
 
 79.49 
 
 66.94 
 
 5857 
 
 182 
 
 2500 
 
 23.1 
 
 17.8 
 
 15 
 
 75 
 
 82.27 
 
 69.28 
 
 60.62 
 
 195 
 
 2680 
 
 23.9 
 
 18.3 
 
 16 
 
 80 
 
 84.97 
 
 71.55 
 
 62.61 
 
 208 
 
 2870 
 
 24.7 
 
 19. 
 
 17 
 
 85 
 
 87.07 
 
 73.32 
 
 64.16 
 
 221 
 
 3055 
 
 25.5 
 
 19.6 
 
 18 
 
 90 
 
 90.13 
 
 75.90 
 
 67.41 
 
 234 
 
 3240 
 
 262 
 
 20.1 
 
 19 
 
 95 
 
 92.60 
 
 77.98 
 
 68.23 
 
 247 
 
 3420 
 
 27. 
 
 20.7 
 
 20 
 
 100 
 
 95.00 
 
 80.00 
 
 70.00 
 
 260 
 
 3750 
 
 28.5 
 
 22.2 
 
 22 
 
 110 
 
 99.64 
 
 83.90 
 
 73.42 
 
 286 
 
 4000 29.8 
 
 23. 
 
 24 
 
 120 
 
 104.06 
 
 87.63 
 
 76.68 
 
 312 
 
 4460 
 
 31.1 
 
 23.9 
 
 26 
 
 130 
 
 108.32 
 
 91.22 
 
 79.81 
 
 388 
 
 4850 
 
 32.4 
 
 24.7 
 
 28 
 
 140 
 
 112.20 
 
 94.66 
 
 82.82 
 
 364 
 
 5250 
 
 33.6 
 
 25.5 
 
 30 
 
 150 
 
 116.35 
 
 97.98 
 
 85.73 
 
 396
 
 STRENGTH OF MATERIALS. 407 
 
 ON THE STRENGTH OF xMATLRIALS. 
 
 THE strengtn of materials is a subject of great import- 
 ance in mechanics, aud one which, of all the branches of 
 ihis useful science, is the least understood. Several very 
 eminent mathematicians have exercised their talents and 
 ingenuity in forming tneories for estimating the strengtn of 
 beams accord ing to the various positions in which they are, 
 but unfortunately, they made no experiments ; therefore, 
 they had no belter foundation than mere hypothesis ; con- 
 sequently are totally at variance with practice. 
 
 It is not intended, however, in this short abstract, to 
 perplex the reader with theory, but to furnish the artisan 
 with a few properties, which to him will be more useful 
 than many discordant suppositions. 
 
 A body may be exposed to four different kinds of strains. 
 1st. It may be torn asunder by some force applied in the 
 direction of its length, as in the case of ropes, &c. 2d. It 
 may also be crushed by a force applied in the direction of 
 its length, as in the case of pillars, posts, &c. 3d. It may 
 be broken across by a force acting perpendicularly to its 
 length, as in joints, levers, &c. 4th. It may be wrenched 
 or twisted by a force acting in a kind of circular direction 
 at the extremity of a lever, as in the case of wheel-axles, 
 &c. 
 
 The first of these, viz. the direct cohesion of bodies, is one 
 which seldom comes under the consideration of the mechan- 
 ic or engineer ; and if any former experiments can be ob- 
 tained, they are generally sufficient for his purpose ; or no 
 reason can be assigned why the strength should not vary 
 directly as the section of fracture, and is totally indepen- 
 dent of the length in position, except so far as the weight 
 of the body may increase the force applied. Neglecting 
 this, and supposing the body uniform in all its parts, the 
 ttrenglh of bodies exposed to strains in the direction oj 
 their length, is aireciiy proportionate to their transverti 
 area, whatever may be their Jigure, length, or position.
 
 408 STRENGTH OF MATERIALS. 
 
 Experiments on the direct cohesion of all bodies are at- 
 tended with great difficulty, in consequence of the enor- 
 mous force required to produce a separation of the parts, in 
 bars of any considerable dimensions. 
 
 Some experiments of this kind, however, have been 
 made, the results of which are as follow, all reduced to the 
 section of a square inch. 
 
 Ibs. 
 
 f Japan, 19,501 
 
 | Barbary, 22,000 
 
 Copper Cast, -I Hungary, 31,000 
 
 Anglesea, 34,000 
 
 I Sweden, 37,000 
 
 r Ordinary, 65,000 
 
 frrn Bar J Stirian > 78 000 
 
 iron uar, 1 BestSwedishSt Russian, 84,000 
 
 L Horse Nails, 71,000 
 
 Steel Bar J Soft ' 120 ' 00 
 
 ) Razor tempered, 150,000 
 
 r Malacca, 3,100 
 
 Banco, 3,600 
 
 Tin Cast, ^ Block, 3,800 
 
 | English Block, 5,200 
 
 L English Grain, 6,500 
 
 Lead Cast, 860 
 
 Regulus of Antimony, 1,000 
 
 Zinc, 2,600 
 
 Bismuth, 2,900 
 
 It is very remarkable that almost all mixtures of metala 
 are stronger or more tenacioas than the metals themselves, 
 much depending upon the proportion of the ingredients ; 
 and these proportions are different in metals. 
 
 Oak, 9,000 
 
 Ash, 17,000 
 
 Pine, from 10,000 to 13,000
 
 STRENGTH OF MATERIALS. 409 
 
 On the Resistance of Bodies ichen pressed itngitudinully. 
 
 It is obvious that a body when pressed endwise, by a 
 sufficient force, may be crushed and destroyed, either by 
 a total separation of the matter by which it is composed, 
 or by bending it, whereby it is broke across : if the length 
 of the body be very inconsiderable the former is the almost 
 certain result ; but if its length be much more than its 
 hreadlh and thickness, it generally bends before breaking. 
 
 Although many experiments, and some very intricate 
 analytical investigations have been made upon this subject, 
 yet little can be advanced that will be of use to the practi- 
 cal engineer. It may be observed, that a pillar of hard 
 stone of Giory, whose section is a square foot, will bear 
 with perfect safety 664,000 Ibs. ; and its extreme strength 
 is 871,000 Ibs. 
 
 Good brick will carry with safety 320,000 Ibs. on a 
 square foot ; and chalk, 9,000 Ibs. 
 
 It requires a power of 400,000 Ibs. to crush a cube of 
 one-quarter of an inch of cast iron. 
 
 The most usual strain, and therefore the one with 
 which it is most important for us to be well informed is, 
 that by which a body is broken across, from the force of 
 weight acting perpendicularly or obliquely to its length, 
 while the beam itself is supported by its two extremities, 
 or by one end fixed into a wall, or otherwise. 
 
 From various experiments which have been made, the 
 following results have been deduced : 
 
 1. The lateral strength of beams are inversely as their 
 lengths. 
 
 2. The lateral strengths of the beams are directly as 
 . their breadth. 
 
 3. The lateral strength of beams are as the square of 
 their depth. 
 
 4. In square beams the lateral strengths are as the cube 
 of one side. 
 
 5. In round beams as the cube of the diameter. 
 
 6. The lateral strength of a beam with its narrow face 
 upwards, i* to its strength with the broad face upwards as 
 
 35
 
 410 STRENGTH OF MATERIALS. 
 
 the breadth of the broader face to the breadth of the nar 
 rower. 
 
 7. The strength of oeam supported only at its extremes, 
 is to the strength of the same when fixed at both ends, as 
 1 to 2. 
 
 8. The strength of a beam with the weight or load sus- 
 pended from the centre is to the strength when the load is 
 equally divided in the length of the beam, as 1 to 2. 
 
 According to t!>e experiments made by Mr. Banks, the 
 worst or weakest piece of oak he tried bore 6 JO pounds, 
 though much bended, and 2 pounds more broke it. The 
 strongest piece broke with 974 pounds. 
 
 The worst piece of Deal bore 480 pounds, but broke 
 with 4 more. The best piece bore 690 pounds, but broke 
 with a little more. i 
 
 The weakest cast iron bar bore 2190 pounds, and 
 strongest 2980 pounds. 
 
 Also, these experiments were made upon pieces 1 inch 
 square, the props exactly 1 foot asunder, and the weight 
 suspended from the centre, the ends lying loose. 
 
 fly way of illustration we will add a few examples for the 
 exercise of the Reader. 
 
 What weight suspended from the middle of an oak 
 beam, whose length is 10 feet, and each side of its square 
 end 4 inches ; will break it when supported at each end 1 
 
 By article 1st, the lateral strengths of beams arc in- 
 versely as the lengths, and (article 4) as the cube of one 
 side. 
 
 Then, as a piece 1 foot long and 1 inch square bore 
 66 : > pounds, one 10 feet long would bear 66 Ibs., and 66 
 multiplied by 64, the cubeof 4 = 4224 pounds the weight, 
 the above beam would support. If the ends of the beano 
 were prevented from rising it would bear 8448 pounds ; 
 and if the weight was equally diffused in its length, it 
 would support 16896 pounds. 
 
 Required the strength of a hollow shaft of cast iron sup- 
 ported at its two extremes, 5 inches diameter, the diame- 
 ter of the hollow being 4 inches, and the length of th 
 shaft 10 feet?
 
 
 STRENGTH OF MATERIALS. 411 
 
 First find the strength of a solid shaft 5 inches diame- 
 ter, and then that of one 4 inches, which deduced from th 
 former, gives its strength. 
 
 The strength of round beams are as the cubes of theif 
 diameter, and the cube of 5 is 125 ; this multiplied by 170, 
 the strength of a round bar 1 inch diameter and 10 feet 
 long, gives 21.375 pounds for the strength of a solid shaft 
 5 inches diameter and 10 feet long. 
 
 The cube of 4 is 64 multiplied by 171, equals 10,944 
 pounds, the strength of a solid shaft 3 inches diameterand 
 10 feet long. Now 21,375 10,944= 10,431 pounds, 
 the strength of the hollow shaft required. 
 
 N. B. '1 he diameter of a solid having the same quantity 
 of matter with the tube is 3, but the strength of it would 
 not be half that of the ring. Engineers have of late in- 
 troduced this improvement into their machines, the axles 
 of cast iron being made hollow, when the size and other 
 circumstances will admit of it. 
 
 Required the strength of a piere of deal 6 inches broad, 
 2 inches deep, and 5 feet long, placed edgeways, and the 
 weight suspended from the centre ? 
 
 Jlnsicer, 6624 pounds. 
 
 What weight will a cast iron beam bear supported in the 
 centre, the length of the beam being 6 feet 8 inches deep, 
 and 1 inch thick ? 
 
 Jlnsicer, 10 tons, 8 cwt 2 quarters, and 8 Ibs. 
 
 If a plank be three inches %ick, and 12 inches broad, 
 ow much more will it bear with its edge than with its flat 
 Bide uppermost ? 
 
 Answer, 4 times more with its edge uppermost. 
 
 With respect to the fourth strain : viz. the twist to which 
 bars or shafts in an upright position are liable by the wheel 
 which drives them, and the resistances they have to over- 
 come, little that will be satisfactory can be advanced. Mr. 
 Banks observes, that a cast-iron bar an inch square, and 
 fixed at the one end, and 631 pounds suspended by a wheel 
 of 2 feet diameter, fixed on the other end, will break by the
 
 412 STRENGTH OF MATERIALS. 
 
 twist : though some have required more than 000 pounds 
 in similar situations to break them by the twist. 
 
 The strength to resist the twisting strain is as the cube 
 of like lateral dimensions. 
 
 In concluding these plain statements it may be necessa 
 ry to remind our readers, that in applying these rules to 
 practical purposes, care should be taken to make the beams, 
 &c. sufficiently strong : if they are but just able to support 
 the stress they will be in danger of breaking. In most 
 cases the strength should be 2 or 3 times the stress, and 
 where the stress may be in equal, or the pressure exerted 
 in a variable manner, by jerks, &c. the strength should be 
 considerably more than that. 
 
 In all the preceding examples the beams are supposed 
 only just able to support the load. 
 
 The following are the results of experiments made by 
 Mr. Emerson, which state the load that may be safely 
 borne by a square inch rod of each. 
 
 Founds avoirdupoto 
 
 *Iron rod, an inch square, will bear, 76,400 
 
 Brass, - 35,600 
 
 Hempen rope, - 19,600 
 
 Ivory, 15,700 
 
 Oak, box, yew, plumtree, - - 7,850 
 
 Elm, ash, beech, .... 6,070 
 
 Walnut, plurn, .... 5,360 
 
 Red pine, holly, elder, plane, crab, - 5,000 
 
 Cherry, hazel, 4,760 
 
 Alder, asp, birch, willow, . - 4,290 
 
 Lead 430 
 
 Free stone, - . - - 914 
 
 Mr. Barlow's opinion of this table is, "We shall u,,<y 
 observe here, that they all fall very short of the uUh *ta 
 trength of the woods to which they refer." 
 
 Mr. Emerson also gives the following practical rule, viz. 
 
 * Tenacity of copper compared with iron is 5 : 9 nearly, or 1 : I A 
 k . copper being 1, iron is IX
 
 STRENGTH OF MATERIALS. 413 
 
 " that a cylinder, whose diameter is d inches, loaded to 
 one-fourth of its absolute strength, will carry as follows : 
 
 ciot. 
 
 Iron, - - . 135 X d 2 
 Good rope, - - 22 x d 2 
 
 Oak, - - - 14 X d 2 
 Pine, - . - 9 X d 8 
 
 Captain S. Brown made an experiment on Welsh pig 
 iron, and the result is described as follows : 
 
 "A bar of cast iron, Welsh pig, 1^ inch square, 3 feet 
 6 inches long, required a strain of 1 1 tons 7 cwt. (25,424 
 libs,) to tear it asunder, broke exactly transverse, without 
 being reduced in any part ; quite cold when broken, par- 
 tides fine, dark bluish grey colour." From this experi- 
 ment, it appears that 16,265 libs will tear asunder a square 
 inch of cast iron. 
 
 Mr. G. Rennie also made some experiments on cast 
 iron, and the result was, " that a bar one inch square, cast 
 horizontal, will support a weight of 18,656 libs and one 
 cast vertical, will support a weight of 19,488 libs." 
 
 There have been several experiments made on mallea 
 ble iron, of various qualities, by different engineers. 
 
 The mean of Mr. Telford's experiments, is 29| tons. 
 The mean of Capt. S. Brown's do. is 25 do. 
 
 and the mean between these two means, is 27 tons, near- 
 ly ; which may be assumed as the medium strength of a 
 malleable iron bar 1 inch square. 
 
 From a mean, derived by experiments, performed by 
 Mr. Barlow, it appears that the strength of direct cohesion, 
 on a square inch of 
 
 Kb*. 
 
 Box - . is about - - 20,000 
 Ash - - - 17,000 
 
 Teak 15,000 
 
 Pine 12,000 
 
 35*
 
 414 
 
 STRENGTH OF MATERIALS. 
 
 Beech - 
 Oak - 
 Pear - 
 Mahogany 
 
 11,500 
 
 10,000 
 
 9,800 
 
 8,000 
 
 Each of these weights may be taken as a correct data 
 for the cohesive strength of the wood to which they belong , 
 Dut this is the absolute and ultimate strength of the fibres ; 
 and therefore, if the quantity that may be safely borne be 
 required, not more thau two-thirds of the above values 
 must be used. 
 
 TABLE 
 Of Sizes and Strength of Chains. 
 
 Size of 
 chains. 
 
 Will carry 
 
 Weiptit of 
 chains per 
 fathom. 
 
 inch 
 
 3 tons 
 
 14 Ib. 
 
 tV 
 
 H 
 
 18 
 
 .6. __ 
 
 6 
 
 24 
 
 ii 
 
 7* 
 
 28 
 
 3 
 
 4 " 
 
 9 - 
 
 32 
 
 ii- 
 
 11 
 
 38 
 
 f 
 
 13 
 
 44 
 
 tt 
 
 15 
 
 50 
 
 i 
 
 17 
 
 56 
 
 if 
 
 19 
 
 62 
 
 H - 
 
 21*- 
 
 70 
 
 iA- 
 
 24 
 
 78 
 
 i| 
 
 27 
 
 86 
 
 1ft 
 
 30 
 
 96 
 
 If 
 
 33 
 
 108 
 
 lf-6- 
 
 36 
 
 115 
 
 H- 
 
 40 
 
 125
 
 SPECIFIC GRAVITY. 
 
 41A 
 
 A Table of Specific Gravities of Bodies. 
 
 Platina (pure) 
 
 23000 
 
 Tin 
 
 7320 
 
 Fine gold 
 
 19400 
 
 Clear crystal glass 
 
 3150 
 
 Standard gold 
 
 17724 
 
 Granite 
 
 3000 
 
 Quicksilver (pure) 
 
 14000 
 
 Marble and hard 
 
 
 Do. (common) 
 
 13600 
 
 stone 
 
 2700 
 
 Lead 
 
 11325 
 
 Common green 
 
 
 Fine silver 
 
 11U91 
 
 glass 
 
 2600 
 
 Standard silver 
 
 10535 
 
 Flint 
 
 2570 
 
 Copper 
 
 9000 
 
 Common stone 
 
 2520 
 
 Copper halfpence 
 
 8915 
 
 Clay 
 
 2160 
 
 Gun metal 
 
 8784 
 
 Brick 
 
 2000 
 
 Cast brass 
 
 8000 
 
 Common earth 
 
 1984 
 
 Steel 
 
 7850 
 
 Nitre 
 
 1900 
 
 Iron 
 
 7645 
 
 Ivory 
 
 1825 
 
 Cast iron 
 
 7425 
 
 Brimstone 
 
 1810 
 
 Coal 
 
 1250 
 
 Solid gunpowder 
 
 1745 
 
 Boxwood 
 
 1030 
 
 Sand 
 
 1520 
 
 Sea water 
 
 1030 
 
 Ash 
 
 800 
 
 Common water 
 
 1000 
 
 Maple 
 
 755 
 
 Oak 
 
 925 
 
 Elm 
 
 600 
 
 Gunpowder close 
 
 
 Pine 
 
 650 
 
 shaken 
 
 937 
 
 Charcoal 
 
 400 
 
 Gunpowder in a 
 
 
 Cork 
 
 240 
 
 loose heap 
 
 836 
 
 Air at a mean state 
 
 If 
 
 Note. The several sorts of wood are supposed to be 
 dry. Also, as a cubic foot of water weighs just 1000 
 ounces avoirdupois, the numbers in this Table express, not 
 only the specific gravities of the several bodies, hut also 
 the weight of a cubic foot of each in avoirdupois ounces; 
 and therefore, by proportion, the weight of any other quan- 
 tity, or the quantity of any other weight, may be known. 
 Also, 100 cubic inches of common air weigh nearly 31 
 grains troy, or If drams avoirdupois.
 
 416 
 
 WEIGHT OF MALLEABLE 
 
 TABLES OF THE WEIGHT OP MALLEABLE AND 
 CAST IRON PLATES, BARS, &c. 
 
 TABLE of the Weighl of a Square Foot of Cast and 
 
 Malleable Iron, Copper and Lead, from 1-16JA, 
 
 to 2 inches thick. 
 
 Thick. 
 
 Cast iron. 
 
 Mall. iron. 
 
 Copper. 
 
 Lead. 
 
 Libs. oz. 
 
 Libs. oz. 
 
 Libs. oz. 
 
 Libs. oz. 
 
 1 sixteenth 
 
 2 6.6 
 
 2 7.8 
 
 2 15 
 
 3 11 
 
 2 
 
 4 13.3 
 
 4 15.6 
 
 5 14 
 
 7 6 
 
 3 - 
 
 7 4. 
 
 7 7.4 
 
 8 13 
 
 11 1 
 
 4 
 
 9 10.6 
 
 9 15.2 
 
 11 12 
 
 14 12 
 
 5 
 
 12 1.3 
 
 12 7.1 
 
 14 11 
 
 18 7 
 
 6 
 
 14 8. 
 
 14 14.9 
 
 17 10 
 
 22 2 
 
 rr ___ 
 
 16 14.7 
 
 17 6.7 
 
 20 9 
 
 25 13 
 
 8 
 
 19 5.3 
 
 19 14.5 
 
 23 8 
 
 29 8 
 
 9 
 
 21 12. 
 
 22 6.3 
 
 26 7 
 
 33 3 
 
 10 
 
 24 2.7 
 
 24 14.2 
 
 29 6 
 
 36 14 
 
 11 
 
 26 9.3 
 
 27 6. 
 
 32 5 
 
 40 9 
 
 12 
 
 29 
 
 29 13.8 
 
 35- 4 
 
 44 4 
 
 13 
 
 31 6.7 
 
 32 5.6 
 
 38 3 
 
 47 15 
 
 14 
 
 33 13.4 
 
 34 13.4 
 
 41 2 
 
 51 10 
 
 15 
 
 36 4. 
 
 37 5-3 
 
 44 1 
 
 55 5 
 
 1 inch 
 
 38 10.7 
 
 39 13.1 
 
 47 
 
 59 
 
 it 
 
 43 8. 
 
 44 12.7 
 
 52 14 
 
 66 1 
 
 H - 
 
 48 5.3 
 
 49 12.3 
 
 58 12 
 
 73 12 
 
 If 
 
 53 2.7 
 
 54 12. 
 
 64 10 
 
 81 2 
 
 li - 
 
 58 
 
 59 11.6 
 
 70 8 
 
 88 8 
 
 if 
 
 62 13.4 
 
 64 11.3 
 
 76 6 
 
 95 14 
 
 H - 
 
 67 10.7 
 
 69 10.9 
 
 82 4 
 
 103 4 
 
 2 
 
 77 5.4 
 
 79 10.2 
 
 94 
 
 118
 
 AND CAST IRON PLATES, BARS, ETC. 
 
 417 
 
 TUILK of the Weight of a. Lineal Foot of Malleable and Cast Iron Bart.frtm 
 
 (3 -IGtA* to 3 inches square. 
 
 
 
 
 
 ROUND RODS. 
 
 The IGths on the 
 
 Sixteenths 
 on the side. 
 
 Area in 
 square 
 
 sixteenths. 
 
 Ounces weight. 
 
 Ounces weight 
 
 side is the diameter 
 of rod. 
 Ounces weight. 
 
 6 
 
 36 
 
 7.4736 
 
 
 5.83 
 
 7 
 
 49 
 
 10.1724 
 
 
 7.99 
 
 8 
 
 64 
 
 13.2864 
 
 12.8960 
 
 10.43 
 
 9 
 
 81 
 
 16.8156 
 
 ' 
 
 13.20 
 
 10 
 
 100 
 
 20.7600 
 
 
 16.30 
 
 11 
 
 121 
 
 25.1196 
 
 
 19.72 
 
 12 
 
 144 
 
 29.8944 
 
 29.0160 
 
 23.47 
 
 13 
 
 169 
 
 35.0844 
 
 
 27.53 
 
 14 
 
 196 
 
 40.6896 
 
 
 
 31.94 
 
 15 
 
 225 
 
 46.7100 
 
 . .- 
 
 36.44 
 
 linch 
 
 256 
 
 53.1456 
 
 51.5840 
 
 41.50 
 
 1 
 
 289 
 
 59.9964 
 
 . . 
 
 46.80 
 
 2 
 
 324 
 
 67.2624 
 
 . . . 
 
 52.47 
 
 3 
 
 361 
 
 74.9436 
 
 . 
 
 58.46 ' 
 
 4 
 
 400 
 
 83.0400 
 
 80.6000 
 
 64.81 
 
 5 
 
 441 
 
 91.5516 
 
 . ; 
 
 71.41 
 
 6 
 
 484 
 
 100.4784 
 
 . . . 
 
 78.37 
 
 7 
 
 529 
 
 109.8204 
 
 . 
 
 85.66 
 
 8 
 
 576 
 
 119.5774 
 
 116.0640 
 
 93.27 
 
 9 
 
 625 
 
 129.7500 
 
 
 101.21 
 
 10 
 
 676 
 
 140.3376 
 
 . 
 
 109.46 
 
 11 
 
 729 
 
 151.3404 
 
 . 
 
 118.05 
 
 12 
 
 784 
 
 162.7584 
 
 157.9760 
 
 126.95 
 
 13 
 
 841 
 
 174.5916 
 
 . 
 
 136.19 
 
 14 
 
 900 
 
 186.8400 
 
 . 
 
 145.74 
 
 15 
 
 961 
 
 199.5036 
 
 . . 
 
 155.62 
 
 2 inches 
 
 1024 
 
 212.5824 
 
 206.3360 
 
 165.82 
 
 1 
 
 1089 
 
 226.0764 
 
 . . . 
 
 176.34 
 
 2 
 
 1156 
 
 239.9856 
 
 . > 
 
 187.19 
 
 3 
 
 1225 
 
 254.3100 
 
 . . 
 
 198.36 
 
 4 
 
 1296 
 
 269.0496 
 
 261.1440 
 
 209.86 
 
 5 
 
 1369 
 
 284.2044 
 
 
 221.68 
 
 6 
 
 1444 
 
 299.7744 
 
 . . . 
 
 233.83 
 
 7 
 
 1521 
 
 315.7596 
 
 
 246.30 
 
 8 
 
 1600 
 
 332.1600 
 
 322.4000 
 
 259.09 
 
 9 
 
 1681 
 
 348.97^6 
 
 
 272.20 
 
 10 
 
 1764 
 
 366.2064 
 
 . . . 
 
 285.64 
 
 11 
 
 1849 
 
 383.8524 
 
 i . 
 
 299.41 
 
 12 
 
 1936 
 
 4019136 
 
 390.1040 
 
 313.49 
 
 13 
 
 2025 
 
 420.8900 
 
 . 
 
 327.91 
 
 14 
 
 2116 
 
 439.2816 
 
 . . 
 
 342.64 
 
 15 
 
 2209 
 
 458.5884 
 
 . 
 
 357.70 
 
 3 inches 
 
 3304 
 
 4783104 
 
 464.2560 
 
 373.09
 
 418 SPECIFIC GRAVITY. 
 
 Example to show the application of the foregoing lablt 
 to find the weight of Flat Iron. 
 
 What is the weight of a flat bar of malleable iron 3 in- 
 ches broad, f thick, and 50 feet long ? 
 
 3 X 16 = 48 X 3 = 144 square 16ths, section of bar : 
 look in the column of areas in the Table, and opposite 
 144 is 29.8944 oz. weight of one foot of the bar, multiply 
 29.8944 by 50 feet = 1494.72 oz. or 93.42 Ibs. 
 
 Find the sixteenths in the section of the bar, and look 
 for the number in the column of areas ; if the number be 
 not exact, take the nearest to it 
 
 The foregoing Tables have been calculated from Hut- 
 ton's Specific Gravities ; those of cast and malleable iron 
 and lead agree very nearly with those given by other au- 
 th'ors ; but the specific gravity of copper, though heavier 
 than that given by Hatchett, which i.s 8.800 ; still, from 
 copper being frequently alloyed with lead, it is supposed 
 that Hutton's, which is 9000, will be nearest the weight 
 of copper commonly used. 
 
 As a Table of Specific Gravities is often found useful, 
 I have inserted the following ; but for calculating the 
 weights of metals, I would recommend Dr. Hutton's 
 Table. See page 49. 
 
 TABLE OF SPECIFIC GRAVITIES. 
 
 Weight of a cubic Inc* 
 
 Specific Gravity. in ounces avoir. 
 
 Arsenic, .... 5763 3.335 
 
 Cast antimony, ... 6702 3.878 
 
 Cast zinc, .... 7190 4.161 
 
 Cast iron, .... 7207 4.165 
 
 Cast tin, .... 7291 4.219 
 
 Bar iron, .... 7788 4.507 
 
 Cast nickel, . . . 7807 4.513 
 
 Cast cobalt, . - - - 7811 4.520 
 
 Hard steel, . . . 7816 4.523 
 
 Soft steel, .... 7833 4.533
 
 SPECIFIC GRAVITY. 
 
 419 
 
 Cast brass, 
 Cast copper, 
 Cast bismuth, 
 Cast silver, - 
 Hammered silver, 
 Cast lead, - 
 Mercury, 
 Jeweller's gold, 
 Gold coin, 
 Cast gold, pure, 
 Pure gold, hammered, 
 Platinum, pure, 
 Platinum, hammered, 
 Platinum wire, 
 
 JVb/e. 
 mering. 
 
 Weight 
 Specific Gravity. in 
 
 - 8395 
 
 8788 
 
 - 9822 
 
 - 10474 
 
 - 10510 
 11352 
 
 - 13568 
 
 - 15709 
 
 - 17647 
 . 19258 
 
 - 19361 
 
 - 19500 
 
 - 20336 
 21041 
 
 of a cubic inch 
 unces avo.r 
 
 4.85M 
 
 5.0S5 
 
 5.684 
 
 6.061 
 
 6.082 
 
 6.569 
 
 7.872 
 
 9.091 
 
 10.212 
 
 11.145 
 
 11.212 
 
 11.285 
 
 11.777 
 
 12.176 
 
 All metals become specifically heavier by ham- 
 
 STONES, EARTHS, &C. 
 
 
 Specific Gravity. 
 
 in Ib3. avoir. 
 
 Brick, 
 
 2000 
 
 125.00 
 
 Sulphur, 
 
 2033 
 
 127.08 
 
 Stone, paving, 
 
 2416 
 
 151.00 
 
 Stone, common, 
 
 - 2520 
 
 157.50 
 
 Granite, red, 
 
 - 2654 
 
 165.84 
 
 Glass, grceii, 
 
 2642 
 
 
 Glass, white, 
 
 - 2892 
 
 
 Glass, bottle, 
 
 2733 
 
 
 Pebble, 
 
 . 2664 
 
 166.50 
 
 
 
 167.00 
 
 Marble, 
 
 - 2742 
 
 171.38 
 
 Chalk, 
 
 2784 
 
 174.00 
 
 Basalt, 
 
 - 2864 
 
 179.00 
 
 Hone, white razor, 
 
 2876 
 
 179.75 
 
 Limestone, 
 
 - 3179 
 
 198.68 
 
 
 RESINS, &C. 
 
 
 Wax, 
 
 897 
 
 
 Tallow, 
 
 !*' . - 945 
 
 
 Bone of an ox, 
 
 1659 
 
 
 Ivory, 
 
 - 1S22 

 
 420 SPECIFIC GRAVITY. 
 
 LIQUIDS. 
 
 Weight of a 
 Specific Gravity. in Iba. avoir. 
 
 Air at the earth's surface, . If 
 
 Oil of turpentine, . . . 870 
 Olive oil, .... 915 
 
 Distilled water, . . .1000 
 Sea water, . . . . 1028 
 Nitric acid, . . . .1218 
 Vitriol, .... 1841 
 
 WOODS. 
 
 Cork, 246 15.00 
 
 Poplar, .... 383 23.94 
 
 Larch, 544 34.00 
 
 Elm and new English pine, 556 34.75 
 
 Mahogany, Honduras, . - 560 35.00 
 
 Willow, .... 585 36.56 
 
 Cedar, 596 37.25 
 
 Pitch pine, ... 560 41.25 
 
 Pear tree, .... 661 41.31 
 
 Walnut, .... 671 41.94 
 
 Pine, forest, .... 694 43.37 
 
 Elder, ; 695 43.44 
 
 Beech, 696 43.50 
 
 Cherry tree, ... 715 44.68 
 
 Teak, .... 745 46.56 
 
 Maple and Riga pine, . 750 46.87 
 
 Ash and Dantzic oak, . . 760 47.50 
 
 Yew, Dutch, ... 788 49.25 
 
 Apple tree, . . . .793 49.56 
 
 Alder, .... 800 50.00 
 
 Yew, Spanish, .... 807 50.44 
 
 Mahogany, Spanish, . . 852 53.25 
 
 Oak, American, . . . 872 54.50 
 
 Boxwood, French, . . 912 57.00 
 
 Logwood, . . . .913 57.06 
 
 Oak, English, ... 970 51.87 
 
 Do. sixty years cut, . . 1170 73.12 
 
 Ebony, .... 1331 83.18 
 
 l.ignumvitce, .... 1333 83.31
 
 APPLICATION. 421 
 
 Application of the foregoing Table. 
 
 A block of marble, measuring 6 feet long and 4 feet 
 square, lies at a wharf, and the wharfinger wishes to know 
 if his 10 ton crane is sufficiently strong to lift it. 
 
 6 X 4 X 4 = 96, cubic feet in the block. 
 171.38 Ibs. weight of a cubic foot. (See Table.) 
 
 - = 7 ton 7 cwt. weight of block. 
 
 fbs. in I ton = 2240 
 
 The 10 ton crane is therefore sufficiently strong to lift it. 
 
 There are severaj slabs of limestone which measure al- 
 together 300 cubic feet, and it is proposed to bring them 
 down a river on a raft formed of teak logs, and which can 
 most conveniently form a raft 42 feet long and 18 feet 
 broad, what depth shall it require to be to float the slabs ? 
 
 198.7 Ibs. weight of a cubic foot of limestone. (See Table.) 
 = 62.5 Ibs. weight of a cubic feet of water. 
 
 16 
 
 198.7 X 300 
 
 18 X 42 X 62.5 raft. 
 
 1000 : 12 : : 745 : 9, that is a cubic foot of teak sinks 9 
 inches in water, of course 3 inches of wood above water ; 
 
 therefore-f- = 5 feet depth the raft will sink with the slafte, 
 
 3 
 
 which, added to 9 inches, gives the depth the raft will sink 
 in the water, and therefore the raft should not be made less 
 than 6 feet deep. 
 
 12 : 6 : : 9 : 4.5 = depth the raft will sink. 
 
 1.25 = depth the slabs will sink the raft. 
 6.75 = depth the raft will sink in the watei 
 when carrying the slabs.
 
 422 
 
 PROPERTIES OF BODIES. 
 
 TABLE of the Properties of Various Bodies. 
 
 BODIES. 
 
 rtc Gravity. 
 
 3 
 3 
 
 a 
 
 - 
 
 ronacquare 
 without per- 
 t alteration. 
 
 at degrees. 
 
 ve force of a 
 arc inch. 
 
 | ' 
 -1 
 
 i l.s of H 
 
 t of water. 
 
 |1 
 
 
 1 
 
 I 
 
 !=! 
 
 1 
 
 s 
 
 r 
 
 3 
 
 lu 
 < j 
 
 n 
 
 
 
 
 
 
 
 o 
 
 
 
 WOODS. 
 
 
 Libs. 
 
 Libs. 
 
 
 
 
 
 
 Ash 
 
 Beech 
 
 0.75 
 0.696 
 
 475 
 45.3 
 
 3540 
 2300 
 
 
 ... 
 
 -- 
 
 -- 
 
 .23 
 
 .15 
 
 Kim 
 Y. l!ow and Bed Pine 
 
 0.544 
 0.557 
 
 34. 
 34.8 
 
 334( 
 
 
 
 
 
 3 1 
 
 White do. 
 
 Mahogany 
 
 0.47 
 056 
 
 293 
 35. 
 
 3WK 
 
 
 
 
 
 .23 
 
 .24 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 METALS. 
 
 
 
 
 
 
 
 
 
 Cast Brass 
 
 837 
 
 50625 
 
 6700 
 
 IRTfl 
 
 18000 
 
 
 
 .435 
 
 Cast Iron 
 
 7.207 
 
 450. 
 
 1530) 
 
 
 
 930f( 
 
 ... 
 
 1. 
 
 Copper 
 .Malleable Fron 
 
 l'.6 
 
 549. 
 475. 
 
 17800 
 
 2548 
 
 - - _ 
 
 33000 
 
 
 
 1.12 
 
 Hammered do. 
 
 
 4W. 
 
 
 
 
 
 
 
 t i i **aa 
 
 11 IK 
 
 709 5 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 at Tin 
 
 7291 
 
 4557 
 
 2P8( 
 
 
 
 
 
 1P2 
 
 
 
 
 
 
 
 
 
 
 Cast Gun Metal 
 
 8.153 
 
 o09.13 
 
 10000 
 
 _ - - 
 
 ... 
 
 
 
 .65 
 
 STONE, ke. 
 
 
 
 
 
 
 
 
 
 Brick 
 
 1.841 
 
 115. 
 
 
 
 
 275 
 
 
 .066 
 
 
 Chalk 
 
 3215 
 
 1447 
 
 
 
 
 
 
 
 Clay 
 
 2. 
 
 T25 
 
 125. 
 
 
 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 Rid Porphyry 
 
 2^1 
 2 75 
 
 170. 
 
 
 ... 
 
 
 35568 
 
 
 
 
 o j]3 
 
 
 
 
 
 
 
 
 Bath do. 
 
 1.975 
 
 1-23.4 
 
 ... 
 
 ... 
 
 478 
 
 
 .0~7 
 
 
 Dundee do. 
 
 S-tial 
 
 U0.8 
 
 
 
 26GI 
 
 
 .002 
 
 
 y the lost column of this Table, the rules for the strength of cast iron can tx 
 applied to the various bodies.
 
 TABLE OF WEIGHTS, ETC. 423 
 
 TABLE of the Weight of Cast Iron Pipes. 
 
 jo '?. 
 
 b'jj 
 
 c 
 
 Weight. 
 
 1 
 
 
 ii 
 
 j 
 
 Weight. 
 
 1 
 
 ~z 
 
 si. 
 
 Weight 
 
 1~7 
 
 ft 6 
 
 t 
 
 
 
 12 
 
 6* 
 
 
 9 
 
 3 
 
 2 
 
 21 
 
 p 
 
 1 
 
 9 
 
 7 
 
 2 
 
 8 
 
 
 ft 6 
 
 ) 
 
 
 
 21 
 
 
 
 9 
 
 1 
 
 1 
 
 21 
 
 
 | 
 
 9 
 
 10 
 
 1 
 
 2 
 
 i 
 
 ft 6 
 
 ) 
 
 
 
 21 
 
 
 
 9 
 
 6 
 
 ) 
 
 14 
 
 2 
 
 i 
 
 9 
 
 5 
 
 
 
 24 
 
 
 ft 6 
 
 ) 
 
 1 
 
 4 
 
 7 
 
 
 9 
 
 2 
 
 ! 
 
 7 
 
 
 
 9 
 
 6 
 
 2 
 
 8 
 
 2 
 
 6 
 
 ) 
 
 1 
 
 3 
 
 
 
 9 
 
 3 
 
 
 
 7 
 
 
 
 9 
 
 7 
 
 3 
 
 20 
 
 
 6 
 
 
 
 2 
 
 
 
 
 
 9 
 
 3 
 
 } 
 
 20 
 
 
 
 9 
 
 10 
 
 3 
 
 
 
 2J 
 
 6 
 
 J 
 
 1 
 
 16 
 
 
 
 9 
 
 4 
 
 3 
 
 5 
 
 12; 
 
 
 9 
 
 5 
 
 1 
 
 16 
 
 
 6 
 
 
 
 2 
 
 10 
 
 
 
 9 
 
 6 
 
 2 
 
 4 
 
 
 
 9 
 
 6 
 
 3 
 
 9 
 
 
 6 
 
 
 
 3 
 
 10 
 
 7* 
 
 
 9 
 
 3 
 
 2 
 
 4 
 
 
 
 9 
 
 8 
 
 1 
 
 
 
 3 
 
 a 
 
 
 
 2 
 
 20 
 
 
 
 9 
 
 3 
 
 1 
 
 6 
 
 
 
 9 
 
 11 
 
 
 
 21 
 
 
 9 
 
 1 
 
 
 
 6 
 
 
 
 9 
 
 4 
 
 
 
 22 
 
 13 
 
 
 9 
 
 5 
 
 2 
 
 20 
 
 
 9 
 
 1 
 
 1 
 
 12 
 
 
 
 9 
 
 5 
 
 
 
 10 
 
 
 
 9 
 
 7 
 
 
 
 14 
 
 
 9 
 
 1 
 
 3 
 
 6 
 
 
 
 9 
 
 7 
 
 
 
 
 
 
 
 9 
 
 8 
 
 2 
 
 7 
 
 
 9 
 
 s 
 
 1 
 
 
 
 8 
 
 
 9 
 
 3 
 
 2 
 
 4 
 
 
 
 9 
 
 11 
 
 2 
 
 12 
 
 3J 
 
 9 
 
 
 
 3 
 
 
 
 
 
 9 
 
 4 
 
 1 
 
 25 
 
 13? 
 
 
 9 
 
 5 
 
 3 
 
 7 
 
 
 9 
 
 1 
 
 
 
 21 
 
 
 
 9 
 
 5 
 
 1 
 
 18 
 
 
 
 9 
 
 7 
 
 1 
 
 12 
 
 
 9 
 
 1 
 
 2 
 
 14 
 
 
 
 9 
 
 7 
 
 ] 
 
 16 
 
 
 
 9 
 
 8 
 
 3 
 
 16 
 
 
 9 
 
 8 
 
 
 
 8 
 
 8J 
 
 
 9 
 
 3 
 
 3 
 
 8 
 
 
 
 9 
 
 11 
 
 3 
 
 24 
 
 
 9 
 
 8 
 
 2 
 
 
 
 
 
 9 
 
 4 
 
 2 
 
 26 
 
 14 
 
 
 9 
 
 6 
 
 
 
 4 
 
 4 
 
 9 
 
 1 
 
 1 
 
 10 
 
 
 
 9 
 
 5 
 
 2 
 
 22 
 
 
 
 9 
 
 7 
 
 2 
 
 16 
 
 
 9 
 
 1 
 
 3 
 
 12 
 
 
 
 9 
 
 7 
 
 3 
 
 8 
 
 
 
 9 
 
 9 
 
 1 
 
 
 
 
 9 
 
 2 
 
 1 
 
 12 
 
 9 
 
 
 9 
 
 4 
 
 
 
 
 
 
 
 9 
 
 12 
 
 1 
 
 14 
 
 
 9 
 
 2 
 
 3 
 
 21 
 
 
 
 9 
 
 5 
 
 
 
 4 
 
 14ft 
 
 
 9 
 
 6 
 
 
 
 24 
 
 4J 
 
 9 
 
 1 
 
 2 
 
 2 
 
 
 
 9 
 
 6 
 
 
 
 2 
 
 
 
 9 
 
 7 
 
 3 
 
 14 
 
 
 9 
 
 2 
 
 
 
 4 
 
 
 
 9 
 
 8 
 
 
 
 26 
 
 
 
 9 
 
 9 
 
 2 
 
 2 
 
 
 9 
 
 2 
 
 2 
 
 14 
 
 9J 
 
 
 9 
 
 4 
 
 
 
 18 
 
 
 
 9 
 
 12 
 
 3 
 
 6 
 
 
 9 
 
 ?, 
 
 
 
 21 
 
 
 
 9 
 
 5 
 
 1 
 
 
 
 15 
 
 
 9 
 
 6 
 
 1 
 
 21 
 
 5 
 
 9 
 
 ] 
 
 2 
 
 22 
 
 
 
 9 
 
 6 
 
 1 
 
 6 
 
 
 
 9 
 
 8 
 
 
 
 14 
 
 
 9 
 
 2 
 
 1 
 
 10 
 
 
 
 9 
 
 8 
 
 2 
 
 20 
 
 
 
 9 
 
 9 
 
 3 
 
 7 
 
 
 9 
 
 2 
 
 3 
 
 17 
 
 10 
 
 
 9 
 
 4 
 
 1 
 
 10 
 
 
 
 9 
 
 13 
 
 
 
 26 
 
 
 9 
 
 3 
 
 1 
 
 24 
 
 
 
 j) 
 
 5 
 
 1 
 
 26 
 
 
 
 9 
 
 16 
 
 3 
 
 5 
 
 5J 
 
 9 
 
 1 
 
 3 
 
 10 
 
 
 
 
 6 
 
 2 
 
 14 
 
 15f 
 
 
 9 
 
 
 
 2 
 
 14 
 
 
 9 
 
 2 
 
 2 
 
 
 
 
 
 
 9 
 
 
 
 8 
 
 
 
 9 
 
 8 
 
 I 
 
 14 
 
 
 9 
 
 3 
 
 
 
 IS 
 
 10J 
 
 
 
 4 
 
 2 
 
 14 
 
 
 
 9 
 
 10 
 
 
 
 10 
 
 
 9 
 
 3 
 
 3 
 
 7 
 
 
 
 
 5 
 
 3 
 
 7 
 
 
 
 9 
 
 13 
 
 2 
 
 17 
 
 
 9 
 
 5 
 
 
 
 12 
 
 
 
 
 7 
 
 
 
 
 
 
 
 9 
 
 17 
 
 1 
 
 6 
 
 6 
 
 9 
 
 2 
 
 
 
 
 
 
 
 
 n 
 
 2 
 
 C 
 
 16 
 
 
 9 
 
 7 
 
 
 
 22 
 
 
 9 
 
 2 
 
 2 
 
 21 
 
 11 
 
 
 
 4 
 
 3 
 
 14 
 
 
 
 9 
 
 8 
 
 3 
 
 7 
 
 
 9 
 
 :< 
 
 1 
 
 17 
 
 
 
 
 6 
 
 
 
 11 
 
 
 
 9 
 
 10 
 
 l 
 
 20 
 
 
 9 
 
 -t 
 
 
 
 lo 
 
 
 
 
 7 
 
 1 
 
 7 
 
 
 
 9 
 
 14 
 
 
 
 8 
 
 
 9 
 
 5 
 
 2 
 
 2(1 
 
 
 
 9 
 
 9 
 
 
 20 
 
 
 
 1 
 
 17 
 
 3 
 
 14 
 
 f>i 
 
 9 
 
 2 
 
 
 
 if. 
 
 1H 
 
 i 
 
 9 
 
 5 
 
 
 
 7 
 
 
 
 9 
 
 21 
 
 3 
 
 4 
 
 
 9 
 
 2 
 
 3 
 
 20 
 
 
 1 
 
 9 
 
 6 
 
 1 
 
 12 
 
 
 . 
 
 9 
 
 2t- 
 
 3 
 
 '21
 
 424 BORING AND TURNING. 
 
 The foregoing Table of the weight of cast iron pipes, 
 gives the length of pipe according to the diameter of bore 
 as generally used in practice. 
 
 Diameter of bore in inches. 
 Thickness of metal in inches. 
 Length of pipe in feet. 
 
 It is found to be of great use in making out estimates 
 of pipes : for instance, it is required to know the weight 
 of a range of pipes 225 feet long, 7 inches diameter of 
 bore, and metal f of an inch thick. 
 9)225 
 
 25 pipes in the whole length. 
 
 One pipe weighs 4 . . 22, which multiplied by 25, is 
 equal to 104 . 3 . 18, or 5 tons, 4 cwt 3 quarters, 18 libs, 
 weight of the whole range. 
 
 The following is a Table of th velocity of motion, for 
 boring cast iron cylinders, pumps, &c. and heavy turn- 
 ing, with fixed cutters. 
 
 It will be observed, that the surface bored is constantly 
 the same, 78.54 feet per minute ; this velocity is found to 
 be the most advantageous : a velocity greater than this, 
 not only takes the temper out of the cutters, but also 
 causing more heat, expands the metal ; and if the ma- 
 chine stops but for a few seconds, a mark is left from the 
 tontraction of the metal. 
 
 Turning has a velocity double to that of boring.
 
 BORING AND TURNING. 
 
 425 
 
 TABLE. 
 
 BOEING. 
 
 TURNING. 
 
 Inches 
 diameter. 
 
 Revolutions of 
 bar per minute. 
 
 Inches 
 diameter. 
 
 Revolution of 
 shaft per minute. 
 
 1 
 
 25. 
 
 1 
 
 50. 
 
 2 
 
 12.5 
 
 2 
 
 25. 
 
 3 
 
 8.33 
 
 3 
 
 16-67 
 
 4 
 
 6.25 
 
 4 
 
 12.50 
 
 5 
 
 5. 
 
 5 
 
 10. 
 
 6 
 
 4.16 
 
 6 
 
 8.32 
 
 7 
 
 3.57 
 
 7 
 
 7.15 
 
 8 
 
 3.125 
 
 8 
 
 6.25 
 
 9 
 
 2.77 
 
 9 
 
 5.55 
 
 10 
 
 2.5 
 
 10 
 
 5. 
 
 15 
 
 1.66 
 
 15 
 
 3.33 
 
 20 
 
 1.25 
 
 20 
 
 2.50 
 
 25 
 
 1. 
 
 25 
 
 2. 
 
 30 
 
 O.S33 
 
 30 
 
 1.667 
 
 35 
 
 0.714 
 
 35 
 
 1.430 
 
 40 
 
 0.625 
 
 40 
 
 1.250 
 
 45 
 
 0.56 
 
 45 
 
 1.12 
 
 50 
 
 0.5 
 
 50 
 
 1. 
 
 60 
 
 0.417 
 
 60 
 
 0.834 
 
 70 
 
 0.358 
 
 70 
 
 0.716 
 
 80 
 
 0.313 
 
 80 
 
 0.626 
 
 90 
 
 0.278 
 
 90 
 
 0.556 
 
 100 
 
 0.25 
 
 100 
 
 0.50 
 
 N. B. The progression of the cutters may be l-16th ot 
 iin inch for the first cut, and for the last l-24th. 
 
 If hand tools are employed in turning, the velocity 
 stay bo considerably increased. 
 
 36*
 
 426 BUILDING. 
 
 BUILDING. 
 
 LAYING FLOORS. 
 
 Flooring boards are mostly made of pine. The first class 
 are selected free from knots, shakes, sap-wood, or cross- 
 grained stuff; the second class consists of boards also free 
 from shakes and sap-wood, but not from small sound knots ; 
 the third class contains the residue of any parcel, or such 
 boards as cannot be included in either of the preceding 
 classes. When an agreement is entered into for the erec- 
 tion of a building, the quality of the boards should be spe- 
 cified, to prevent subsequent disputes. As all boards shrink 
 in the course of time, and as the quantity of their contrac- 
 tion increases with their dimensions, floors which are laid 
 with very broad boards, soon exhibit, at the joints, wide 
 fissures that have an unpleasant appearance. It is therefore 
 the practice in good houses, not only to select the best part 
 of the wood, but to cut the boards into narrow scantlings ; 
 so that, if properly seasoned, and laid close at first, their 
 shrinking afterwards is so small as to make no openings 
 of consequence. Boards about five inches broad may be 
 reckoned narrow, but when they measure nine inches or 
 more in the same direction, they must be considered broad. 
 
 The manner of jointing floor boards, and fastening 
 them down upon the joists, is performed in a variety of 
 ways, the most usual of which is, to plane the edges of the 
 board quite square, that is, at right angles to the upper and 
 under surface, and then, placing them as closely to each 
 other as possible, to nail them down from the upper surface. 
 Sometimes, particularly when the wood is known to be in- 
 sufficiently seasoned after the first board has been fastened 
 down, the fourth board is secured iti like manner, the two 
 intermediate boards are then made somewhat wider than the 
 space to receive them, and forced into their places by jump- 
 ing upon them. To do this with the most ease andadvan. 
 tage, the intermediate boards are laid aslant, so as to be 
 highest in the middle, and those edges which are placed 
 together being sloped a little, so as to form rather less than 
 a right angle with their respective upper serfaces, they are, 

 
 - 
 
 BUILDING. 427 
 
 by an adequate weight, at once compressed and levelled. 
 The fourth board of the last series becomes the first of th 
 next, and the operation, which is called folding the boards, 
 is repeated till the floor is finished. The nails are driven 
 iu a little below the surface of these boards, and the cavity 
 Is filled with glazier's putty. But in rooms not intended to 
 be carpeted, and yet where a neat and clean appearance is 
 indispensable, the use of putty must be avoided, and the 
 nails must not be driven in from the top. This object is 
 obtained by doweling the joints, that is, driving wooden 
 pins into them in the middle of their thickness, and par- 
 allel to the surface, in the same manner as the coopers joint 
 the boards forming the ends of their casks. In this case, 
 one-half of each pin entering the edges placed together, 
 the boards, if the dowels be sufficiently numerous and pro- 
 perly placed, cannot rise or sink but in conjunction. The 
 best place for the dowels is in the middle of ihe space be- 
 tween the joints. In the best doweled work, the nails are 
 concealed when the floor is finished, for they are driven 
 in slantwise through the outer edge only of each board. 
 Sometimes the joints of flooring boards are rabbeted, that 
 they may lap over each other a little way, and sometimes 
 toothed into each other, or, as it is technically expressed, 
 ploughed and tongued. When either of these methods is 
 adopted, the boards are not separated on their contraction 
 so as to leave an aperture between each pair, through which 
 any thing can drop ; but such floors are more costly than 
 others, not only on account of the extra labour, but the 
 greater quantity of wood which they require. 
 
 It is always desirable to cover a floor with boards in one 
 length ; but as this may not always be convenient, when 
 it is not done, the ends of the two boards that meet are 
 culled headings. The headings should invariably be upon 
 a joist, and two of them should never be together in the 
 same line. 
 
 Before the boards are laid, it is necessary to examine 
 whether the upper sides of '.he joists all lie in the same 
 plane. The defect they ar<} most liable to, is that of being 
 depressed iu the middle ; in which case they must be 
 raised by the addition of suitable pieces, but if found too 
 protuberant, they must be reduced by the adze.
 
 428 
 
 BUILDING. 
 
 Yellow pine, well seasoned, is one of the best woods 
 that can be selected for floors, and retains its colour for a 
 long time ; whereas the white sort, by frequent washing, 
 becomes blackish and disagreeable in its appearance. 
 
 Proportion of Timbers, SfC. 
 
 In the treatise entitled the " British Carpenter," already 
 referred to, are given the following Tables to show the pro- 
 portions of timbers for small and large buildings : 
 
 PROPORTIONS OF TIMBERS FOR SMALL BUILDINGS 
 
 Bern-ing 
 Height 
 if 8 feet 
 10 
 12 
 
 Posts of Pine 
 Scantling 
 4 inches square 
 
 Bearing 
 Height 
 if 10 feet 
 12 
 14 
 
 Posts of Oak 
 Scantling 
 6 inches square 
 
 10 
 
 Gird 
 Bearinw 
 if 16 feet 
 20 
 24 
 
 >rs of Pine 
 Scantling 
 8 inches by 11 
 10 121 
 12 14 
 
 Gird 
 Bearing 
 if 16 feet 
 20 
 24 
 
 ers of Oak 
 Scantling 
 10 inches by 13 
 12 14 
 14 15 
 
 Joist 
 Bearing 
 if 6 feet 
 9 
 12 
 
 s of Pine 
 Scantling 
 5 inches by 24 
 
 6* 
 
 8 2J 
 
 Jois 
 Bearing 
 f 6 feet 
 9 
 12 
 
 s of Oak 
 Scantling 
 5 inches by 3 
 71 3 
 10 3 
 
 Bridgi 
 Bearing 
 if 6 feet 
 8 
 10 
 
 ngs of Pine 
 Scantling 
 4 inches by 2$ 
 5 2f 
 6 3 
 
 Bridgi 
 Bearin" 
 f 6 feet 
 8 
 10 
 
 ng* of Oak 
 Scantling 
 4 inches by 3 
 
 5 1 
 
 Smalt R 
 Bearing 
 if 8 feet 
 10 
 12 
 
 jfters of Pine 
 Scantling 
 3J inches by 2$ 
 41 2 
 51 21 
 
 Small R 
 Bearing 
 f 8 feet 
 10 
 12 
 
 afters of Oak 
 Scantling 
 4J inches by 3 
 51 3 
 6J 3 
 
 Beams oj 
 Length 
 if 30 feet 
 45 
 60 
 
 Pine, or Ties 
 Scantling 
 6 inches by 7 
 9 8i 
 IS 11 
 
 Beams oj 
 Length 
 f 30 feet 
 45 
 60 
 
 Oak, or Ties 
 Scantlin<r 
 7 inches by 8 
 10 ll t 
 13 15
 
 BUILDING. 
 
 429 
 
 Princ 
 
 Length 
 if 24 feet 
 36 
 48 
 
 pal Rafters t 
 Sea 
 Top 
 5 by 7 
 6J 8 
 8 10 
 
 fPtne 
 ntling 
 Bottom 
 6 by 7 
 8 10 
 10 12 
 
 Princ 
 
 Length 
 if 24 feet 
 36 
 
 48 
 
 'pal Rafters 
 Sea 
 Top 
 7 by 8 
 8 9 
 9 10 
 
 if Oak 
 ntling 
 Bottom 
 8 by 9 
 9 Kt.J 
 10 12 
 
 PROPORTION OF TIMBERS FOR LARGE BUILDINGS. 
 
 Bearing 
 
 Height 
 if 8 feet 
 12 
 16 
 
 Posts oj Pine 
 Scantling 
 5 inc ics square 
 
 10 
 
 Bearing 
 Height 
 if 8 feet 
 12 
 16 
 
 Posts of Oak 
 Scantling 
 8 inches square 
 12 
 16 
 
 Gird 
 Bearin" 
 if 16 feet 
 20 
 24 
 
 rs of Pine 
 Scantling 
 9J inches by 13 
 12 14 
 13J 15 
 
 Gird 
 Bearin" 
 if 16 feet 
 20 
 24 
 
 ers of Oak 
 Scantling 
 12 inches by 14 
 15 15 
 18 16 
 
 Joint 
 Bearing 
 if 6 feet 
 9 
 12 
 
 s of Pine 
 Scantling 
 5 inches by 3 
 7* 3 
 10 3 
 
 Juis 
 Bearing 
 if 6 feet 
 9 
 12 
 
 ',S of Oak 
 Scantling 
 6 inches by 3 
 9 3 
 12 3 
 
 Bridgi 
 Bearing 
 if 6 feet 
 8 
 10 
 
 iigs of Pine 
 Scantling 
 4 inches by 3 
 
 ? I 
 
 Bridg 
 Bearing 
 if 6 feet 
 8 
 10 
 
 ngs of Oak 
 Scantling 
 5 inches by 3J 
 6J 3J 
 8 3J 
 
 Small Rafters of Pine 
 Bearing 1 Scantling 
 if 8 feet 4J inches by 3 
 10 | 5J 3 
 12 6i 3 
 
 Small R 
 Bearing 
 f 8 feet 
 10 
 12 
 
 afiers of Oak 
 Scantling 
 5J inches by 3 
 7 3 
 9 3 
 
 Beams oj 
 Length 
 if 30 feet 
 45 
 60 
 
 "Pine, or Ties 
 Scantling 
 7 inches by 8 
 
 10 Hi 
 
 13 15 
 
 Beams oj 
 Length 
 if 30 feet 
 45 
 60 
 
 Oak, or Ties 
 Scantling 
 8 inches by 9 
 11 12J 
 14 16 
 
 Principal Rafters of Pine 
 ' Scantling 
 , Length Top Botton* 
 if 24 feet 7 by 9 8 by 9 
 1 36 8 9 9 10J 
 1 48 9 10 10 12 
 
 Principal Rafters of Oak 
 Scantling 
 Length Top Bottom 
 if 24 feet 8 by 9 9 by 12 
 36 9 10 10 10 
 48 10 13 12 14,
 
 430 BUILDING. 
 
 The author of the preceding Tables observes, that 
 though they seem so plain as not to need explanation, yet 
 a few remarks might be subjoined with propriety. All 
 binding or strong joists, he then adds, ought to be half as 
 thick again as common joists ; that is, if a common joist 
 be given three inches thick, a binding joist should be four 
 inches and a half thick, although of the same depth. 
 
 If it be not convenient to allow the posts in partitions 
 to be square, which is the best form, in such ca>es, multi- 
 ply the square of the side of the posits, as here given, by itself: 
 for instance, if it be six inches square, then as six times six 
 is thirty-six, to keep this post nearly to the same strength, 
 find two numbers producing the same amount; as suppose 
 the partition to be four inches thick, then let the post be 
 nine inches the other way, so that nine times four being 
 thirty-six, the area of its horizontal section is the same, 
 and its strength nearly equal to the square post. 
 
 Posts that go to the height of two or three stories, need 
 not hold the proportions given in the table, because at 
 every floor they meet with a tie. Admit a post to be thirty 
 feet high, and that in this height there are three stories, 
 two often feet and one of eight feet ; look for posts ot 
 pine ten feet high, their scantling is five inches square, 
 that is, twenty. five square inches, which double for the 
 two stories ; and also take that of eight feet high, being 
 four inches, that is, sixteen inches square, all which being 
 added together, make sixty-six inches ; so that such a 
 post would be rather more than eight inches square. On 
 occasion it may be lessened in each story as it rises. 
 
 All beams, ties, and principal rafters, ought to be cut 
 or forced in framing to a chamber, or roundness, on the 
 upper side, and the convexity may be about one inch in 
 eighteen or twenty fret. The reason is, that all timber, 
 partly from its own weight, but principally from the weight 
 of the covering or other burden it has to bear, will swag 5 
 and unless prepared in this manner, that it may never be. 
 come concave, a degree of unsightliness, and often of 
 inconvenience, will be produced. 
 
 The joists in floors, the purlines (or timbers into which 
 (he small rafters are tenoned in roofs,) &c., should not ex- 
 -eed twelve feet in the length of their bearing, or from sup-
 
 BUILDING. 431 
 
 % 
 
 port to support. The strong joists of floors should not be 
 at a greater distance than five feet, nor common joists 
 more than ten or twelve inches apart. 
 
 According to the experiments of Muschenbroek, pine is 
 able to bear compression in the direction of the length of 
 its fibres, or to sustain as a post, a much greater weight than 
 oak, but is far inferior to oak when the weight is suspend- 
 ed. In the preceding tables, therefore, the scantlings of 
 pine bearing posts and principal rafters are properly made 
 less than those of oak ; but for other timbers, particularly 
 for ties, many are of opinion that the proportions of the 
 author's tables should be reversed, and the scantling 
 which he has assigned to pine should be given to oak.
 
 432 
 
 BRICKLAYERS' WORK. 
 
 _g "S 5 A-S 
 <S-J2 S"5-5 
 
 m I" = -3 > 
 
 -*9'o 2 
 
 .5 ._ w O O 
 
 JS ~~ o 
 
 w,a TS w 
 
 a S 
 
 |fj?s 
 
 1 'sjTc 4 ^ 
 C u- -Q cs e 
 
 ^H = 
 
 fill! 
 
 c^'^-S 
 Ml'-*" 
 
 |11 
 
 ~ w 
 
 ^3 
 g 
 
 snr 
 
 Iflp 
 
 f!lt! 
 
 
 i fl * 5 
 
 i <D G < -^ 
 
 i.2: t- s S 
 
 ilS* 
 
 1 ffisj 
 
 '1-s'i.sjS 
 ^an^H| 
 
 2 ti) -5 
 
 ni|i^ 
 
 ijB Ji S S 
 
 S 
 
 OOOOO 
 
 00 l^- lO Ol C<J 
 
 O 
 5 rf 
 
 OOl 
 "0 t^ i 
 
 H (^ < 
 
 00
 
 BRICKLAYERS' WORK. 
 
 435 
 
 
 1 8 
 
 l 
 
 S 
 
 wco aoia i-c 
 
 S^S-S? 
 
 ioco -*cq t>. 
 ""^ ci 06 ^ o 
 
 CO i i i-t W CO 
 
 00 * CO 
 CO 00 >; 
 
 'COOCNJlO 
 
 : * ^ 5 -i 
 
 I CM CO * CO 
 
 PH (N W -^ 
 
 "37- 
 
 So b 
 
 *|SS18S88 
 
 J i-Goaoj-jein 
 
 I* 
 
 6 = 
 
 IJ 
 
 Si 
 
 11 
 
 gas 
 O c 
 
 Tf FH QO 00 t- O 
 
 06 o" i-5 1* co' o 
 
 W CO CO <* CD 00 
 
 
 r-J <N C^' CO '*' id CO 
 
 lO CD t- 00 00 O5 rH 
 
 r-i r-5 rH <M CO ^ Tf 
 
 CO 00 00 TO O O % 
 
 2 CO ^ S CD 2 
 
 i-( OJ ^J* t CO t- 
 
 20
 
 434 CIRCLES AND DIAMETERS. 
 
 CIRCLES AND DIAMETERS. 
 
 THE diameter of a circle being given, to find tne cir- 
 cumference ; or the circumference being given, to find 
 the diameter. 
 
 Multiply the diameter by 3.1416, and the product will 
 be the circumference ; or, 
 
 Divide the circumference by 3.1416, and the quotien* 
 wiH be the diameter 
 
 NOTE 1. As 7 is to 22, so is the diameter to the cir. 
 iumference ; or, as 22 is to 7, so is the circumference to 
 .he diameter. 
 
 EXAMPLES. 
 
 (1.) If the diameter of a circle be 17, what is the cir- 
 cumference? 
 
 Here 3.1417 X 17 = 53.4072 = circumference. 
 
 (2.) If the circumference of a circle be 354, what ia 
 the diameter ? 
 
 354. 000 
 
 Here -r-r- = 112.681 diameter. 
 o 141o 
 
 (3,) What is the circumference of a circle whose 
 diameter is 40 feet? Ans. 125.6640. 
 
 (4.) What is the circumference of a circle whoso 
 diameter is 12 feet ? Ans. 37.6992. 
 
 (5.) If the circumference of the earth be 25,000 miles, 
 what is the diameter 1 Ans. 7958 nearly. 
 
 (6.) The base of a cone is a circle ; what is its diame- 
 ter when the circumference is 54 feet ? Ans. 20.371 8.
 
 DIAMETERS AND CIRCUMFERENCES. 
 
 435 
 
 The following Table contains diameters and circumfe- 
 rences in inches and parts, from half an inch to 65 inches, 
 
 ll 
 
 3 
 
 Ill l.f.S 1 
 
 = 2 
 
 I 
 
 = s 
 
 I 
 
 2 
 
 f 
 
 | 
 
 c 2 
 
 ^ 
 
 Jl 
 
 il 
 
 |l 
 
 fl 
 
 l 
 
 <|3 
 
 = | 
 
 1 1 
 
 C "* 
 
 ll 
 
 * 
 
 u 5 
 
 || 
 
 
 
 | m 
 
 = 
 
 || 
 
 1 
 
 11 
 
 1 S 
 
 H 
 
 1 
 
 = 
 
 
 5 1 
 
 a 
 
 J 
 
 5 
 
 l 
 
 5 
 
 5 
 
 i 
 
 1.57 
 
 Lo^ 
 
 42.4 
 
 26$ 
 
 83/25 
 
 39* Il24.1 
 
 "2$ 
 
 16493 
 
 
 3.14 
 
 [4 
 
 43.98 
 
 27 
 
 84.8240* 
 
 12566 
 
 ^3 5 
 
 163.5 
 
 r 
 
 4.71 
 6.2-S 
 
 ll* 
 
 45.55 
 47.12 
 
 s* 
 
 83.3940$ 
 87.9641 
 
 127.23.53$ 
 
 128.8 54 
 
 168 
 169.64 
 
 f 
 
 7.85 
 9.42 
 
 iOa 
 
 48.70 
 50.26 
 
 f 
 
 89.53 
 91.1 
 
 41$ 
 42 
 
 130.37 
 13194 
 
 54$ 
 
 171.21 
 172.78 
 
 4 2 
 
 10.99 
 1256 
 
 1 
 
 51 3 
 
 5340 
 
 M) 8 
 
 92.67 
 9428 
 
 4'2$ 
 43 
 
 133.51 
 135. 
 
 55$ 
 16 
 
 174.35 
 175.9:.' 
 
 4i 114.13 
 
 7$ 
 
 54.97 
 
 30$ 
 
 9581 
 
 43$ 
 
 130.65 
 
 16$ 
 
 177,5 
 
 5" 1157 
 
 18 
 
 5i,54 
 
 SI 
 
 9739 
 
 44 
 
 138.23 
 
 57 
 
 179 
 
 51 
 
 17.28 
 
 8$ 
 
 58.11 
 
 31$ 
 
 9896 
 
 44$ 
 
 1398 
 
 57$ 
 
 180.64 
 
 fi 2 
 
 18.85 
 
 [y 
 
 59.69 
 
 
 100 53 
 
 45 
 
 141.37 
 
 58 
 
 182.21 
 
 6$ 20.42 
 
 19$ 
 
 HI. 26 
 
 ^2$ 
 
 1021 
 
 45$ 
 
 14294 
 
 58$ 
 
 183.78 
 
 7 |21.99 
 
 20 
 
 62.8 
 
 33 
 
 103.67 
 
 46 
 
 144.52 
 
 59 
 
 185.35 
 
 7$ 123.56 
 
 20$ 
 
 644 
 
 33$ 
 
 105.24 
 
 46* 
 
 146 
 
 59$ 
 
 186.92 
 
 8 125.13 
 
 21 
 
 65.97 
 
 34 
 
 106.81 
 
 47 
 
 147 65 
 
 60 
 
 188.49 
 
 8$ 126.7 . 
 9 ,28/27 
 
 22^ 
 
 67.54 
 69.11 
 
 35* 
 
 108.3847$ 
 109.9548 
 
 149.22 
 150.79 
 
 60* 
 61 
 
 190 
 191.63 
 
 9$ ,29.84 
 10 131.4 
 
 23* 
 
 70.7 
 72.25 
 
 35$ 
 36 
 
 111.52 
 113 
 
 48$ 
 49 
 
 152.36 
 153.93 
 
 61$ 
 62 
 
 193.2 
 194.77 
 
 10$ 32.98 
 
 23$ 
 
 73.82 
 
 36$ 
 
 11466 
 
 49* 
 
 155,5 
 
 62$ 
 
 193.35 
 
 11 
 
 L2 5 
 
 34.55 
 36.12 
 37.70 
 
 24 
 
 
 
 75.4 
 76.9 
 
 78,54 
 
 37 
 
 3 ^ 
 
 116.23,50" 
 117.8150$ 
 119.3851 
 
 157 
 
 158.65 
 160.23 
 
 63 
 63$ 
 64 
 
 197.92 
 199.49 
 201 
 
 12$ 39.27 
 
 13 J40.84 
 
 25^ 80.11 
 26 J81.68 
 
 I 1 
 
 1209 51$ 
 12252J52 
 
 161.7964$ 
 163.36 65 
 
 202.63 
 204-2 
 
 Required the circumference of a circle of 7 inchea 
 diameter. See the above Table ; in column 1st, is 7 in- 
 ches diameter, and against that, in column 2d, is 21.99, 
 or what might be considered 22.
 
 436 STEAM ENGINE 
 
 \~ ' 
 
 THE STEAM ENGINE RENDERED EASY 
 
 WITH PLATES. 
 
 Having already described the Steam Engine in all its 
 operations, the design here is, to commence with it in its 
 simplest state, and to proceed to a full description of the 
 high and low pressure system ; for the more immediate 
 advantage of new beginners, and those who have not had 
 an opportunity of studying this subject. 
 FIG. I. 
 
 Fig. I. represents a glass tube of about f of an 
 inch wide and seven or eight inches long ; a is a 
 wooden rod about ten inches long, called a piston 
 rod, with a piece of leather wrapped round it at 6, 
 the piston. After the water in the glass tube has 
 been made to boil by the lamp c long enough to 
 expel the atmospheric air, introduce the piston a 
 little way into the tube, and plunge the tube into 
 water, and you will find that the piston will in- 
 j-tantly be driven downwards. Hold the tube over 
 the lamp again, and the piston will be driven up- 
 wards, and so on as often as you please, to heat 
 and cool it. The reasons are these : by plunging 
 the tube into cold water the steam is suddenly 
 condensed, and a vacuum is created, iuto which 
 the piston is forced by the pressure of the at- 
 mospKere. When the water in the bulb resumes the pro- 
 cess of boiling, by being replaced over the lamp, steam 
 is generated below the piston, which expands itself in the 
 tube and forces the piston upwards. 
 
 This is " a steam engine" in its simplest form, and you 
 will readily conceive that if the piston rod is attached to 
 a lever or wheel, it can communicate force and motion. 
 
 In the engine represented in figure I, the piston is forced 
 upwards only by the expansive power of the steam ; when 
 .he steam is condensed and a vacuum is created below the 
 piston, it is forced downwards by the pressure of the atmo
 
 RENDERED EASY. 437 
 
 Bphere. This is what is therefore called "an atmospheric 
 engine." After each stroke of the pistop the cylinder has 
 to be cooled, in order that the necessary condensation of 
 the steam may take place, which occasions a great waste 
 of fuel. There is another inconvenience attending this en- 
 gine, viz. the rate of the motion cannot be well regulated. 
 
 FIG. II. 
 
 Figure II. represents a " double-icorking steam engine." 
 B is a section of the boiler, whih is provided with a safety- 
 valve 6, the use of which is to allow the passage into the at- 
 mosphere of the steam, in case too much should be generated 
 for the safety of the machine. This safety-valve is regula- 
 ted by the lever D E, and the moveable weight D. V U S T 
 indicate the cylinder, r the piston rod, and R the piston, 
 which is filled in, or " stuffed" as it is called, with wool, 
 tow, felt or metal, in such a way as to be as nearly air and 
 steam tight as possible, without creating too much friction 
 against the sides of the cylinder, as the piston moves up 
 and down. K is a box stuffed in like manner, and for the 
 like purpose, through which the piston rod passes. The 
 steam pipe P communicates with the boiler, and through it 
 the steam is conveyed from the boiler to the cylinder. This 
 pipe, it will be observed, is divided into two branches, L 
 and M. This is for the purpose of conveying the steam, 
 either above or below the piston, according as it is required 
 to force the piston down or up. Each branch is provided 
 with a valve or a stop. cock, by which the communication 
 between the boiler and cylinder can be cut off aii.J opened 
 again. On the opposite side of the cylinder are t no similar 
 37
 
 438 STEAM ENGINE 
 
 branches, O and N, forming, where tney unite, the "educ- 
 tion pipe" W, which is connected with the "condenser" C. 
 The branches N being each provided with a valve 01 
 itop-cock, which are alternately opened and closed, and 
 used for the purpose of discharging the steam which has 
 performed its office into the condenser. The condenser 
 is kept constantly cool by surrounding it by a well of cold 
 water. By tnis means, the discharged steam, which passes 
 through the eduction pipe, is instantaneously condensed. 
 The pump Q serves for the important purpose of continu- 
 ally freaing the condenser of air and water, and preparing 
 it for the reception of the discharged steam. 
 
 When the machine is to be set in operation, the water in 
 the boiler B is heated by the furnace F, and a part of it la 
 converted into steam. The four valves L, M, N, and 0, 
 are then all opened, so as to admit the steam from the boiler 
 to pass both above and below the piston, and at the same 
 time to admit of its escape into the condenser, and thence 
 through the pump Q into the open air. This process, which 
 is called "blowing out the engine," has for its object the ex- 
 pulsion of the atmosphere torn every part of the machine. 
 
 This being done the valves or stop-cocks M and are 
 closed, the steam is then admitted through the branch L 
 only, passing the valve or stop-cock L, and entering into 
 the cylinder above the piston, which it forces down to the 
 bottom of the cylinder, and thus imparts the first motion to 
 the engine. As the piston thus descends, the steam which 
 was below it in the cylinder is forced through the branch 
 N and eduction pipe W into the condenser, and being turn- 
 ed into water, is drawn off by the pump Q. The valves 
 or stop-cocks L and N are now closed, and M and are 
 at the same time opened, upon which the steam rushes from 
 the boiler through the steam pipe P and branch M under 
 the piston, and forces it to the top of the cylinder, and the 
 steam which was above the piston then passes through the 
 branch and eduction pipe W into the condenser in like 
 manner, and so on, the opposite valves or stop-cocks open- 
 ing and shutting, alternately, producing an alternate up- 
 ward and downward motion in the piston rod, which being 
 commui.icatcd to the machinery, keeps it in a continual 
 ind regular motion.
 
 RENDERED EASY. 439 
 
 The valves or stop-cocks L, M, N, O, in the branches, 
 are usually opened and shut, and the pump Q worked by 
 the engine, being effected by levers connected with the pis- 
 ion rod, which makes the motion more uniform and regular. 
 
 In this, which is a low-pressure engine, the pressure of 
 the steam is averaged at fifteen pounds a* the square inch, 
 which is equal to the weight of one atmosphere, and the 
 powr is proportioned to the surface of the piston and 
 bore of the cylinder. It is generally calculated by the 
 power of so many horses. The power of the engine may 
 be increased or diminished by increasing or diminishing 
 the size of the piston and cylinder, for in proportion to the 
 pressure of the steam upon the piston, will it be moved 
 up and down with greater or less force. 
 
 FIG. III. 
 
 If the motion required be rotary, the piston rod A, Fig. 
 III., is connected to one end of a lever, whose fulcrum, C, 
 is in the centre, and the other end of the lever, B, is con- 
 nected with the wheel by means of a crank, D. 
 
 The safety. valve 6, Fig. II., is shaped conically, and is 
 Kept in its place by the lever D E, charged with the weight 
 D. This weight can be moved further from or nearer to 
 the safety-valve, according as we wish the steam in the 
 boiler to attain a greater or less degree of elasticity. Al- 
 though it is generally stated that in the low-pressure engine 
 the steam is used as it is generated, at 212, which is equal
 
 440 STEAM ENGINE 
 
 to just one atmosphere, yet it is necessary to attach a 
 small additional weight to the lever D E, to increase the 
 elasticity of the steam in the boiler, to a degree which en- 
 ables it to blow out with force sufficient to prevent the ad- 
 mission of the atmosphere into the machine. 
 
 Instead of the valves and stop-cocks above described for 
 the admission and escape of the steam, a single slide is 
 substituted. It consists, as may be seen in fig. IV. an*d V., 
 in a slide S, which can be moved up and down from L to M. 
 This is effected by the levers M, N, O, and an eccentric, 
 which is moved by the turning of the wheel. When the 
 slide is in the position represented in fig. IV. the steam in 
 the boiler is admitted through the steam pipe P, through the 
 branch q r, and thence through the opening u in the lower 
 part of the cylinder, to force upwards the piston, while the 
 steam that was above the piston is discharged through the 
 passage a b d n o e into the condenser. The next turn ol 
 
 FIG. IT.
 
 RENDERED EASY. 
 
 FIG. V 
 
 '442 
 
 the wheel places the slide S in the position represented in 
 fig. V. The communication being cut off, the steam can 
 no longer pass through the branch q r ; but it has free ac- 
 cess through the branch I d b a into the upper part of the 
 cylinder above the piston, forcing it down, while the steam 
 which was below the piston finds a way opened for its es- 
 cape through the branch turqnoe into the condenser. 
 In the " high pressure engine" the steam from both above 
 and below the piston is discharged, directly into the atmo- 
 sphere ; it therefore occupies less space, as it requires nei- 
 ther condenser, water-well nor air pump. But the atmo- 
 sphere having access to that surface of the piston which is 
 opposite to the steam, and exercising upon it a pressure 
 equal to 15 pounds to the square inch, it follows, that the 
 steam employed for this engine must be confined until it 
 attains an elasticity that is sufficient, first, to overcome that 
 atmospheric pressure, and then to drive the machinery. 
 But when the boiler and cylinder of the high-pressure en-
 
 142 STEAM ENGINE, ETC. 
 
 gine are strong, a powerful pressure can be exercised with 
 a very small volume of steam, but of great elasticity. 
 
 'Inhere are two hollow tubes, each provided with a stop- 
 cock, both communicating with the boiler. One of these, 
 called the "steam gauge," communicates with the steam ; 
 and the other, which communicates with the water, is 
 called the ' water-gauge.'' The jse of the steam and 
 water gauges is to ascertain if the proper quantity of water 
 is iu the boiler. When the stop-cock of the steam guage 
 is opened, if water issues, there is too much of that liquid 
 in the boiler ; if, when the water gauge stop-cock is open- 
 ed, nothing but steam issues, then the water is too low in 
 the boiler. 
 
 There is also attached to some engines, a little instru- 
 ment which is called the "governor." It consists of two 
 balls, each of which is fixed upon the lower end of a lever, 
 the upper end of which lever is loosely connected with an 
 upright shaft by a pin. The shaft is connected with the 
 fly wheel, from which it receives its rotary motion. The 
 balls, according to the law of centrifugal forces, recede 
 from or approach towards the shaft, in the ratio of the 
 velocity of the governor-shaft and fly wheel. The gover- 
 nor is also connected, by appropriate machinery, with a 
 valve in the steam pipe, which valve it opens or shuts; so 
 that if the machine goes faster than it ought to do, the 
 valve of the steam pipe gently closes, and shutting off a 
 portion of the steam from the cylinder, retards the motion ; 
 on the other hand, if the machine goes too slow, the shaft 
 of the governor revolves with less velocity, the balls being 
 less acted upon by the centrifugal force, descend and ap- 
 proach the shaft, and by means of the machinery afore- 
 said, the valve of the steam pipe gently opens and more 
 steam is allowed to pass from the boiler to the cylinder. 
 Thus does the engine regulate its own velocity, making it 
 snore uniform.
 
 MANAGER'S ASSISTANT. 443 
 
 THK 
 
 MANAGERS AND OVERSEERS' ASSISTANT; 
 
 CONTAINING THE 
 
 ART OF CALCULATION IN A COTTON MILL, 
 
 Through all its varions operations, from the Raw Material into Yarn 
 and Cloth. Arranged in a concise and simple manner. By an 
 Operative Spinner. 
 
 INTRODUCTORY. 
 
 It is presumed, that this small treatise will be rendered 
 valuable, not only to Overseers and Managers, but to 
 every one who may ft. ^1 desirous to attain a situation as 
 manager or overseer in a cotton mill. The different 
 branches are illustrated with simplicity and perspicuity, and 
 may be easily understood by those persons who have but 
 little time to devote to study. An individual who fully 
 comprehends the following rules, may discharge the va 
 rious duties attached to an official situation in a cotton-mill, 
 with ease and credit to himself and to the entire satis- 
 faction of his employers. 
 
 MANAGER'S ASSISTANT. 
 
 To find the counts of Cotton, at the end of every operation 
 from the raw material into Yarn. 
 
 Suppose a lap 8 feet long weighs one pound two ounces, 
 allowing the two ounces to waste in going through all its 
 operations. 
 
 RULE. 
 
 840 yards being in one hank, weigh one pound, conse, 
 quently, there must be one hank in the pound, that being 
 multiplied by 3 brings it into feet, and divided by 8 feet, 
 will be the 315th part of a hank
 
 444 MANAGER'S ASSISTANT. 
 
 310 yards in one hank. 
 3 feet in one yard. 
 
 8)2520 
 
 315 Answer required. 
 To find the counts after going tlirougn a caraing engine. 
 
 Suppose a draught of a carding engine to be 78J, and 
 a lap before going through be the 3L5th part of a hank. 
 
 Reduce the 78 f- into fourth, and divide that product I 
 315, and it will be one fourth of a hank. 
 
 
 
 EXAMPLE. 
 
 78* 
 4 
 
 315)315(1 that is | of a hank. 
 315 
 
 To find the draught of a carding engine. 
 
 Suppose the diamater of the doflTer cylinder be 18 inches 
 with a wheel upon the doffer shaft of 30 teeth, and work 
 into another upon the side shaft of 35 teeth, on the other 
 end of the side shaft is a 20 that works into a wheel upon 
 the feed rollers of a 150 teeth, and the diameter of the 
 feed roller is 2 inches. The draught is required. 
 
 Multiply the 30 on the doffer end, by the 20 on the side 
 shaft that works in the wheel upon the feed roller, then by 
 the 2 inches the diameter of the feed roller for a divisor. 
 Then multiply the 1*0 up jn the feed roller by 18 inches 
 the diameter of the doffer ; then by the 35 on the side 
 shaft for a dividend, am 1 the draught will be 78J.
 
 MANAGER'S ASSISTANT. 445 
 
 EXAMPLE. 
 
 30 150 
 
 20 IS 
 
 600 1200 
 
 2 150 
 
 Divisor, 12 00 2700 
 
 35 
 
 13500 
 8100 
 
 945 00(78f Answer required 
 84 
 
 105 
 96 
 
 To find in what proportion a carding engine should cam 
 to furnish the mules with a proper quantity of prepara- 
 tion in changing from one count to another. 
 
 Suppose a pair of mules be spinning 80's weft, with 85 
 turns in a certain length oflap going up at the carding en- 
 gine, weighing 9 Ibs., and the mule changing to 90's twist, 
 with 105 turns : the lap of the same length is required. 
 
 Ninety's twist requiring a lighter lap than 80's weft, 
 and 105 turns require a lighter lap than 85 turns : multiply 
 the 105 by 90's for a divisor, and the 85 turns by 80's, 
 then by 9 pounds, the weight of the lap for a dividend. 
 The answer will be nearly 6 Ib. 7 oz.
 
 416 MANAGER'S ASSISTANT. 
 
 EXAMPLE 
 
 80 65 9 
 
 90 105 
 
 105 85 
 
 90 80 
 
 6800 
 9450 Divisoi. 9 
 
 61200(6 Ib. 7 oz. Answer. 
 56700 
 
 4500 
 
 16 oz.lfi 1 pound. 
 
 27000 
 4500 
 
 72000(7 oz. 
 66150 
 
 8850 
 
 To jini the counts after going through a drawing Jrame. 
 
 Suppose the carding to be of f of a hank, and goes 
 through 3 boxes of drawings, and puts up 6 ends at each 
 box, and the draught of the first box to be 5*, and the so 
 cond to be 6, and the third box to be six and six twenty, 
 thirds. 
 
 RULE: 
 
 Multiply the doubling at each box one Jnto another for 
 a divisor, and the draught of each box one into another 
 for a dividend, and the answer will be one-fourth of a 
 hank, after going through the three heads of drawing, con- 
 sequently, nothing here is gained but doubling. 
 
 The draught of the first box and the doubling, must be 
 brought into fourths, the draught of the last box and the 
 doubling brought into twenty. thirds.
 
 MANAGER'S ASSISTANT. 44? 
 
 
 
 EXAMPLE. 
 
 
 1st 
 
 box 6 ends 
 
 24 
 
 23 1st box 5? 
 
 
 
 6 
 
 6 ends, " 6 
 
 2d, 
 
 6 " 
 
 144 
 
 138 
 
 
 
 138 
 
 144 3d box 6 2 A 8 
 
 3d, 
 
 6 " 
 
 1152 
 
 552 
 
 
 
 432 
 
 552 
 
 
 
 
 144 
 
 138 
 
 Divisor, 19872 
 
 To find the draught oj the last box to gain nothing but 
 
 doubling. 
 
 Suppose 3 heads of drawing have 6 ends put up at each 
 head, and the draught of the first be 5f, and the draught 
 of the second 6 : the draught of the last box is required. 
 
 RULE. 
 
 Multiply the draught of the first and second box for a 
 divisor; then multiply the doubling of three boxes one into 
 another for a dividend, and the draught of the last box wil* 
 be / 3 -. 
 
 JVo/e. The draught of the first box must be brought 
 into fourths, consequently, the dividend must be brought 
 into fourths also. 
 
 EXAMPLE. 
 53 6 
 
 23 36 
 
 6 6 
 
 Divisor, 138 216 
 
 4 
 
 864 
 
 828 (6^. Answer.
 
 448 MANAGER'S ASSISTANT. 
 
 To find the draught of a drawing frame ivith 4 roller*. 
 "When a drawing frame has 4 rollers, there will be 3 
 draughts. The first draught 1, the second roller 2 of a 
 draught. The draught of the front roller is required, al- 
 lowing the whole of the draughts to be 9. 
 
 HULK. 
 
 Multiply the first draught by 1-*- by the second 2, and 
 divide the whole of the draughts that is 9 by that product, 
 and the draught of the first roller will be 3. 
 
 EXAMPLE. 
 
 1 5 3)9 
 
 rt 
 
 3 Answer required. 
 
 Divisor, 3 
 
 To find the counts when the last box drawing has gone 
 
 through a slubbing frame. 
 
 Suppose the last box drawing be -J- of a hank, and go up 
 single at a slubbing frame, with a 20 pinion wheel on the 
 coupling shaft, a 6U top carrier, a 40 back roller wheel, and 
 a 30 change wheel : the counts are required. 
 
 RULE. 
 
 Multiply the 20 pinion wheel by the 30 change wheel 
 for a divisor ; then multiply the 60 top carrier by the 40 
 back roller wheel for the dividend, and the draught will be 
 4, consequently will be one hank in the pound. 
 
 EXAMPLE. 
 30 60 
 
 20 40 
 
 Divisor, 6|00 24|00 
 
 24 (4 draughts, or 1 hank in 
 the pound. Answer required. 
 
 To find the change wheel when the last box drawing has 
 gone through a slubbing frame. 
 
 Suppose the last box drawing be -J- of a hank, and go up 
 single at the slubbing frame with a 20 pinion wheel on the 
 frout roller, and the top carrier 60, and the back roller 
 wheel 40, and the draught to be 4 : the change wheel is 
 required.
 
 MANAGER'S ASSISTANT 44fl 
 
 RU1E. 
 
 Multiply the 20 jpon the front roller, by the draught 4 
 loi a divisor, and the top carrier 60, by the back roller wheel 
 40, for the dividend, the change wheel required will be 30 
 
 EXAMPLE. 
 
 20 60 
 
 4 40 
 
 Divisor, 8JO 2400 
 
 24 (30 Answer. 
 
 
 
 To find the counts after going through a roving billy. 
 Suppose a bobbin of one hank be drawn into a roving 
 *nd put up two ends, with a 20 pinion wheel and an 80 
 top carrier, and a 60 back roller wheel, and a 30 change 
 wheel : the number of hanks of the roving is required. 
 
 RULE. 
 
 Multiply the 20 pinion wheel by the 2 ends put up at the 
 back. Then by the 30 change wheel for a divisor. Then 
 multiply the 80 top carrier by the 60 back roller wheel for 
 a dividend, and the roving required will be 4 hanks. 
 
 EXAMPLE. 
 
 20 80 
 
 2 60 
 
 40 4800 
 
 30 4800 (4 hanks the answer. 
 
 Divisor, 1200 
 
 To draw a bobbin into a roving. 
 
 Suppose a bobbin of one hank be drawn into 4, and go 
 up double at the billy, with a 20 pinion and an 80 top car- 
 rier, and a 60 back roller wheel. The change wheel is 
 equired. 
 
 RULE. 
 
 Multiply the pinion wheel by the 2 ends put up, and 
 then by the 4 hanks roving for a divisor. Then multiply 
 the 80 top carrier by the 60 back roller wheel for the divi- 
 dend, and the change wheel required will be 30. 
 3S 2D
 
 450 MANAGER'S ASSISTAN1. 
 
 EXAMPLE. 
 
 20 80 
 
 2 60 
 
 40 480|0 
 
 4 48 '30 Answer. 
 
 Divisor, 160 
 
 To find the draught of a frame with two heads having tile 
 draught oj the first head given to answer the purpose oj 
 both a slubbing frame, and a roving billy. 
 Suppose the last box drawing be of \ of a bank, and go 
 
 up double at a frame witb two heads, and be drawn into a 
 
 four hank roving, and the draught of the first head be 5. 
 
 The draught of the second head is required. 
 
 RULE. 
 The last box drawing being -J- of a hank, and going up 
 
 double, i of a hank, that multiplied by 4 hanks wanted, 
 
 and divided by the draught of the first head, that is 5 ; 
 
 then the draught of the second head which is required, 
 
 will be 6f . 
 
 EXAMPLE. 
 8 
 4 
 
 6)32 
 
 6f Answer. 
 
 To find the number of stretches upon a set of rovings. 
 Suppose the front roller of a roving billy makes 18 revo- 
 lutions in one stretch, with a worm upon the coupling shaft 
 that drives a wheel of 30 teeth, and a worm upon the 
 same shaft with the 30 wheel, that drives a bell wheel with 
 120 teeth. The number of stretches is required, allow, 
 ing the bell wheel to go once round. 
 
 RULE. 
 
 Multiply the 120 by the 30 for a dividend, and divide 
 by the 18, that is, the revolutions of the front roller, and 
 the number of stretches upon the roving will be 200.
 
 MANAGER'S ASSISTANT. 451 
 
 EXAMPLE. 
 120 
 
 30 
 
 18)3600(200 stretches the answer. 
 To find the counts after going through a mule. 
 Suppose a roving of 4 hanks be drawn into yarn with a 
 20 pinion wheel, au 80 top carrier, a 60 back roller wheel, 
 a 30 change wheel, and the length of the stretch put up 
 60 inches, and the length of the yarn turned out from the 
 rollers 53 inches. The number of hanks is required. 
 
 Multiply .the pinion 20 by the change wheel 30, and the 
 product by 53 inches, that the rollers turn out for a divi- 
 sor ; multiply the 80 top carrier by the 60 back roller 
 wheel, and by the 60 inches put up ; then by the 4 hanks 
 roving for the dividend, and the answer will be 
 
 20 
 30 
 
 EXAMPLE. 
 
 80 
 60 
 
 600 
 53 
 
 1800 
 3000 
 
 Divisor, 31800 
 
 4800 
 60 
 
 288000 
 4 
 
 )1152000 ( 
 95400 
 
 198000 
 190800 
 
 Answer. 
 
 7200 
 
 To find the turns. 
 
 Suppose a thread of yarn requires 30 revolutions of the 
 spindles per inch, and put up 60 inches of a stretch, and 
 the spindles make 20 revolutions for one turn of the rim : 
 the number of turns is required.
 
 152 MANAGER'S ASSISTANT. 
 
 RULE. Multiply the 60 inches put up by the 30 revolu- 
 tions required per inch, and divide by 20 the number of 
 revolutions of the spindle for one turn of the rim, and 
 the number of turns required will be 90. 
 
 EXAMPLE. 
 
 60 
 
 30 
 
 2|0)180|0 
 
 90 Answer. 
 
 To find a wheel to put on the boltom of the long driver, to 
 make the rollers turn out a certain number of inches, 
 in a certain number of turns. 
 
 Suppose the rollers turn out 53 inches in 55 turns, with 
 a 53 wheel on the rim shaft, a 55 wheel on the top of the 
 long driver, 102 upon the coupling shaft, and the circum- 
 ference of the front roller be 3 inches : the wheel on the 
 Dottom of the long driver is required. 
 
 RULE. 
 
 Multiply the 53 wheel on the rim shafrby the 55 turns, 
 and by the 3 inches, the circumference of the front roller 
 for a divisor. Multiply the 55 on the top of the long dri- 
 ver by the 53 inches the rollers turn out, then by the 102 
 on the coupling shaft for the dividend, and the wheel re- 
 quired will be 34. 
 
 EXAMPLE. 
 
 53 55 
 
 55 53 
 
 ~265 ~165 
 
 265 275 
 
 2915 2915 
 
 3 102 
 
 Divisor 8745 5830 
 
 2915 
 
 297330(34 Anawer. 
 26235 
 
 - . 1 34980
 
 MANAGER'S ASSISTANT. 453 
 
 To find a \c\eel to put upon the bottom of the short driver 
 to draw a carriage out a certain number oj inches, i;i 
 a certain number of turns. 
 
 Suppose a carriage to be brought 58 inches in 55 turns, 
 with a 20 upon the rim shaft, a 70 upon the top of the 
 short driver, a 100 scrall wheel, and the circumference of 
 the scrall 18 -ft inches : the wheel upon the bottom of the 
 short driver is required. 
 
 RULE. 
 
 Bring IS-^- into llths, and multiply that by 55 turns, 
 and by the 20 upon the rim shaft for a divisor ; then mul- 
 tiply the 58 inches by the 70 wheel on the top of the short 
 driver, then by the 100 scrall wheel, and reduce that into 
 llths for the dividend, and the wheel on the bottom ol 
 the short driver will be 20. 
 
 18-fr 58 
 
 11 70 
 
 203 4050 
 
 55 100 
 
 1015 
 1015 
 
 11165 4466000 (20 Answer. 
 
 20 
 
 Divisor, 223300 
 
 To find the number of hanlts of the roving from the num- 
 ber of hanks of the mule in spinning. 
 
 Suppose a pair of mules be spinning 44's weft and put 
 up 60 inches, and the carriage gains from the rollers 9 
 inches, with a 20 on the coupling shaft or pinion wheel, 
 and a 100 top carrier, a 30 change wheel, a 50 back relief 
 wheel The number ef hanks of the roving is required.
 
 454 MANAGER'S ASSISTANT. 
 
 RULE. 
 
 Multiply the 40 hanks by the 9 inches the carriage 
 gains, and divide by the 60 inches put up, it will show 
 that 6 hanks are altered by the gaining of the carriage, 
 and 6 hanks subtracted from the 40 hanks, 34 will re- 
 main ; then multiply the 34 by the pinion whe>l 20, and 
 by the change wheel 30 for a dividend, aud rriiltiply the 
 top carrier 100 by the 50 back roller wheel ftv a divisor 
 and the roving required will be 4 gV 
 
 40 
 6 subtracted. 
 
 34 remains. 
 
 
 
 680 
 30 
 
 100 20400 (4^ Answer. 
 
 60 20000 
 
 Divisor, 5000 400 
 
 To change from one count to another without changing 
 the roving. 
 
 Suppose a pair of mules be spinning 40 hanks in the 
 pound with 36 change wheel, and has to change to 60 
 hanks in the pound : the change wheel is required. 
 
 RULE. 
 
 As 60's will require a less change wheel than 40'g, con- 
 sequently, the 40 and 36 must be multiplied together for a 
 dividend, and divide by the 60, aud the change wheel re- 
 quired will be 24.
 
 MANAGER'S ASSISTANT. 455 
 
 EXAMPLE. 
 
 As 60 : 40 36 
 40 
 
 6|0)144|0 
 24 
 
 Co change from one count to another, when the change 
 wheel and roving is required to be altered. 
 
 Suppose a pair of mules to be spinning 40's with a 4 
 hank roving, and a 30 change wheel, and is altered to 60's, 
 With a 7 hank roving : the change wheel is required. 
 
 RULE. 
 
 Multiply the 60 by the 4 hank roving for a divisor ; 
 (h'.n multiply the 40 by the 7 hanks roving v and that by 
 $i 30 change wheel for the dividend, and the change 
 Theel required will be 35. 
 
 EXAMPLE. 
 
 40 4 30 
 60 7 
 
 60 40 
 
 4 7 
 
 Divisor, 2410 280 
 
 30 
 
 84010 (35 Answer. 
 72 
 
 120 
 
 120 
 
 To fnd the circumference of a scroll to draw a carriagt 
 out a certain number of inches, in a certain number 
 oj turns. 
 Suppose a carriage be brought out 58 inches in 55 turns, 
 
 with a 2't wheel upon a rim shaft, a 70 upon the top of the
 
 456 MANAGER'S ASSISTANT. 
 
 short driver, a 20 on the bottom, and a 100 the scroll 
 wheel ; the circumference of the scroll is required. 
 
 Multiply the 55 by the 20 upon the rim shaft ; then by 
 the 20 at the bottom of the short driver for a divisor ; 
 multiply the 58 inches by the 70 on the top of the short 
 driver, then by 100 on the scrall shaft for the dividend, 
 and the circumference of the scrall will be 18-j 5 ,-. 
 
 EXAMPLE. 
 
 55 58 
 
 20 70 
 
 1100 4060 
 
 20 100 
 
 Divisor, 22|000 )406000 (18^ Answer. 
 
 22 
 
 186 
 176 
 
 10 
 
 To find the circumference of a mandosa putty, to draw ovt 
 a carriage a certain number 'of inches, in a certain nm- 
 her of turns. 
 
 Suppose a carnage be brought out 58 inches in 55 turns, 
 and a wheel on the rim shaft of 53 teeth, and a wheel on 
 the top of the long driver of 55 teeth, a 34 on the bottom 
 of the long driver, that works into a wheel on the coupling 
 shaft of 100 teeth, and a wheel of 30 teeth on the sam* 
 shaft that works in one on the mandosa shaft of 250 teeth . 
 the circumference of the mandosa pully is required. 
 
 Multiply the 55 turns by the 53 on the rim shaft, by 34 
 on the bottom of the long driver, by 30 on the coupling 
 shaft for a divisor ; multiply 55 on the top of the long dri- 
 ver by 100 on the coupling shaft, by 260 the man dose
 
 MANAGER'S ASSISTANT. 
 
 45? 
 
 wheel, the 58 inches for the dividend, and the circumfer- 
 ence of the mandosa pull/ will be 27 inches, 89 of a deci- 
 mal, or nearly 28 inches. 
 
 55 
 53 
 
 165 
 275 
 
 2915 
 . 34 
 
 11660 
 8745 
 
 99110 
 
 30 
 
 29733(00 
 
 EXAMPLE. 
 
 55 
 100 
 
 5500 
 260 
 
 330000 
 11000 
 
 1430000 
 58 
 
 11440000 
 7150000 
 
 )829400|00 
 59466 
 
 (2789 
 
 234740 
 
 208131 
 
 266090 or nearly 28 ineheo. 
 237864 
 
 282260 
 267597 
 
 14663 
 To draw a roving into yarn. 
 
 Suppose a thread of 36--f be drawn from a 4 back rov- 
 ir.g, with a twenty pinion wheel, and an 80 top carrier, a 
 6t back roller wheel, and the number of inches put up 60, 
 and the number of inches turned out of the rollers, 63 
 the change wheel is required. 
 39
 
 458 MANAGER'S ASSISTANT. 
 
 RULE. 
 
 Reduce the 36ff into 53rds, then multiply the product 
 by the pinion wheel 20, and by th6 63 inches the rollers 
 turn out for a divisor ; multiply the 80 top carrier by the 
 60 back roller wheel, and by the 60 inches put up, then bj 
 the 4 hank roving ; reduce those products into 53rds for 
 the dividend, and divide it as in whole numbers and the 
 change wheel required will be 30. 
 
 110 
 181 
 
 1920 
 20 
 
 2035200 Div. 
 
 )C10560jOO (30 Answer. 
 61056 
 
 To fold a wheel to put on the middle roller, for the middle 
 roller to draw from the back roller G into 7. 
 
 Suppose the diatneter of the back roller be -f and the 
 diameter of the middle roller to be |- of an inch, and the 
 wheel upon the back roller be 24 : the wheel on the mid- 
 dle roller is required. 
 
 RULE. 
 
 Multiply the 24 on the back roller by the f of the mid. 
 die roller, and divide it by the f of the back roller, and the 
 wheel required to take it up as the back roller delivered it, 
 will be 21 ; that multiplied by 6. and divided by 7, will 
 show that the wheel required on the middle roller to draw 
 6 into 7, will be 18.
 
 MANAGER'S ASSISTANT. 459 
 
 24 
 7 
 
 8)168 
 
 21 
 6 
 
 IS Answer required. 
 To find the draught of a mule. 
 
 S*ip|ose the pinion wheel upon the coupling shaft toa 
 20, th\. top carrier 120, change wheel 38, back roller wheel 
 64, an d the diameter of the back roller of an inch, and 
 the front roller J- : the draught is required. 
 
 RULE. 
 
 Multiply the change wheel 38 by the pinion wheel 20, 
 then f diameter of the back roller for the divisor ; then 
 multiply the top carrier 120 by the back roller wheel 54, 
 then by the diameter of the front roller f for the dividend, 
 and the draught will be 9 -*&. 
 
 EXAMPLE- 
 
 38 120 
 
 20 54 
 
 760 480 .' 
 
 7 600 
 
 Divisor, 5320 
 
 8 
 
 Answer.
 
 460 MANAGER'S ASSISTANT. 
 
 To find the number of revolutions of the spindles for ecerj 
 inch oj yarn. 
 
 Suppose a thread of yarn to be spun with 90 turns, and 
 20 revolutions of the spindle for one turn of the rim, anj 
 puts up 6u inches : the number of revolutions per inch ia 
 required. 
 
 RULE. 
 
 Multiply the 90 turns by the 20 revolutions of the spin- 
 dle, and divide by 60 inches put up, and the number of 
 revolutions per inch will be 30. , 
 
 EXAMPLE. 
 
 90 
 20 
 
 60!0)180|0 
 
 30 Answer. 
 
 To find the counts of yarn, without the assistance of a 
 
 compendious table. 
 
 Suppose one lea or 120 yards weigh 25 grains : the 
 counts an; required. 
 
 RULE. 
 
 Seven thousand grains being one pound, and 7 leas one 
 hank, and a lea being a seventh part of a hank, and 
 weighing 25 grains, 1000 grains must be divided by 25 
 grains, and the counts required will be 40's ; and if 2 leas 
 be token, 2000 must be divided by what it weighs, and 
 so on up to 7 leas. 
 
 EXAMPLE. 
 
 25)1000 (40 Answer. 
 100 
 
 To find in what portion to put twist in yarn per inch, in 
 changing from one count to another. 
 
 Suppose a pair of mules ar spinning 40's twist, with 
 22 J- revolutions cf the spindl per inch, and change to 
 90's twist : the number of revolution* or' the spindle pe 
 inch is required.
 
 MANAGER'S ASSISTANT. 461 
 
 Add 23- revolutions of the spindle for every 10 hanks, 
 aud it shows the number of revolutions required. 
 
 JVb/e. 90's being 50 hanks finer than 40's, multiply 2^ 
 by 5 and it will give 12, that added to the 22 will show, 
 that 90's require 35 revolutions per inch. 
 
 40's weft requiring 16 revolutions per inch, and 12 
 added to that, shows that 90's weft require 29 revolutions. 
 
 EXAMPLE. 
 
 Twist, 22.5 2J5 
 
 12.5 5 
 
 35.0 12|5 
 
 IVeJt, 16.5 25 
 
 12.5 6 
 
 29.0 12.5 
 
 To find the number of stretches upon a cop; 
 
 Suppose a cop run 10 leas with 80 turns of the reel in 
 one lea, and 54 inches in one turn, and the number of 
 inches the mule puts up is 60 : the number of stretches is 
 required. 
 
 RULE. 
 
 Multiply that 10 leas by the 80 turns of the reel in ona 
 lea, then by 54 inches in one turn, and divide by the 60 
 inches put up, and the number of stretches will be 720. 
 
 EXAMPLE. 
 
 10 
 
 80 
 
 800 
 54 
 
 6|0)4320|0 
 
 720 Aniwar. 
 39*
 
 462 MANAGER'S ASSISTANT. 
 
 To find the average counts of a set of Cops. 
 
 Suppose a mule have 420 spindles, and one cop run 10 
 leas, and the whole set weighs 15 pouuds, the average 
 counts are required. 
 
 Multiply the 420 spindles by 10 leas for the dividend, 
 then multiply the 15 pounds by 7 leas in one hank for a 
 divisor, and the average counts will be 40's. 
 
 EXAMPLE. 
 
 15 420 
 
 7 10 
 
 Divisor 
 
 105 4200 (40 AIM. 
 
 420 
 
 To find Ike Weight of a Warp. 
 
 Suppose a warp 270 yard? long, with 33 beers, and 60 
 ends to each beer, and the number of hanks be 34's twist, 
 the weight of the warp is required. 
 
 Multiply the 270 by 33 heers, then by 60 ends in each 
 beer, that will show the number of yards the warp con- 
 tains ; then divide the yards by S40, and it will show the 
 number of hanks it contains ; then divide the number of 
 hanks by 34 hanks in the pound, and it will show the num- 
 ber of pounds; then multiply the remainder by 16, and 
 divide by 34, as before, and the weight of the warp will 
 be 18 pounds 11 ounces
 
 MANAGER'S ASSISTANT. 
 
 463 
 
 270 
 33 
 
 810 
 810 
 
 8910 
 60 
 
 8410)53460(0(34 
 
 5U4 
 
 306 
 352 
 
 540 
 
 5U4 
 
 36 
 
 Ihg. oz. 
 636(18 11 
 34 
 
 296 
 272 
 
 24 
 
 16 
 
 144 
 
 24 
 
 384(11 
 34 
 
 44 
 34 
 
 10 
 
 To find the Weight of Weft to fill a Warp. 
 
 Suppose a warp of 270 yards long be wove into cloth, 
 and allowing.30 yards to mill up in the weaving and other 
 waste, and the breadth of the cloth 29 inches, with 80 pirks 
 in each inch, and the number of hanks of the weft be ?.4 
 in the pound, the weight of the weft is required. 
 
 RULE. 
 
 Subtract 30 yards from the 270 yards, and 240 remain; 
 !hat multiplied by 29 inches, the breadth of the cloth, then 
 by 80 picks per inch, it will show the number of yards ; 
 then divide by 840, and it will bring it into hanks ; then 
 divide the hanks by 34 in the pound, and it will be 19 
 pounds; then multiply the remainder by 16, and divide 
 by 34 as before : it will show the weight of weft required 
 will bo 19 Ibs. 7 oz.
 
 464 MANAGER'S ASSISTANT. 
 
 BX.4.MFLB. 
 270 
 
 30 
 
 ___ 
 
 240 
 29 
 
 ItM. Z. 
 
 2160 662(19 7 
 480 34 
 
 6960 322 
 
 80 300 
 
 8 1|0)55680|0(34 16 
 
 304 16 
 
 628 96 
 
 604 16 . 
 
 240 256(7 
 
 168 23S 
 
 72 18 
 
 7'r. put a pair of mules in a good working condition, when 
 the roller beam, spindle box, Jailer, and altogetlier it oui 
 of order. 
 
 Set the roller beam straight, then with a guage set the 
 carriage strips all at one distance from the bottom centre 
 of the front roller ; when that is done, then wiih a level 
 8(U all the carriage strips at the front of the bevel intend- 
 ed. Set all the ends of the spindle box bottoms at one 
 distance to the carriage ends. String a line along the bot- 
 tom of the spindle box, and set the line about a quarter of 
 nn inch from touching at each end : the best manner of 
 doing this is by diiviug a small nail at each end of the 
 8| indie box, and lapping the Hue around them, and with 
 tut squaring bands square the carriage so that the line ia
 
 MANAGER'S ASSIST AM'. 
 
 465 
 
 clear in the middle and the ends ; and put in the bevel 
 intended for the spindle at each end, and string a line 
 along the top of the spindles also, and set them straight. 
 Then set the faller and the stops at the back to the dis- 
 tance intended the spindles should be from the rollers. 
 
 A TABLE 
 
 Snowing the requisite metnber of revolutions of the spindle 
 for every inch of yarn, of twist and weft, beginning ai 
 40'*, and going up to 200's. 
 
 As no proper calculation can be made on account of the 
 variations of the cotton, but, by observing the following 
 Table, no person will be led into an en-or. 
 
 Twist. 
 
 Revolutions. 
 
 Weft. 
 
 Revolutions. 
 
 40 
 
 221 
 
 40 
 
 16i 
 
 50 
 
 25 
 
 50 
 
 19 
 
 60 
 
 27i 
 
 60 
 
 21i 
 
 70 
 
 30 
 
 70 
 
 24 
 
 80 
 
 32i 
 
 80 
 
 26^ 
 
 90 
 
 35 
 
 90 
 
 29 
 
 10U 
 
 37i 
 
 100 
 
 31* 
 
 110 
 
 40 
 
 110 
 
 34 
 
 120 
 
 42^ 
 
 120 
 
 36i 
 
 130 
 
 45 
 
 130 
 
 39 
 
 140 
 
 47i 
 
 140 
 
 41i 
 
 150 
 
 50 
 
 150 
 
 44 
 
 160 
 
 52i 
 
 160 
 
 46i 
 
 170 
 
 55 
 
 170 
 
 49 
 
 180 
 
 57i 
 
 180 
 
 51i 
 
 190 
 
 60 
 
 190 
 
 54 
 
 200 
 
 621 
 
 200 
 
 56i
 
 466 
 
 MANAGER'S ASSISTANT. 
 
 A TABLE , 
 
 Of ha? fa lea to fry the hanks of bobbins, by penny-weight* 
 and grains, commencing at quarter of a hank and going 
 up to Jive kanks. 
 
 Dwu 
 
 Grains. 
 
 Hanks. 
 
 Dwt. 
 
 Grains. 
 
 Hanks. 
 
 83 
 
 8 
 
 i 
 
 7 
 
 13 
 
 ?! 
 
 55 
 
 13 
 
 1 
 
 7 
 
 5 
 
 
 41 16 
 
 * 
 
 G 
 
 22 
 
 3 8 
 
 33 8 
 
 t 
 
 6 
 
 16 
 
 3-L 
 
 27 18 
 
 1 
 
 6 
 
 9 
 
 3-J- 
 
 23 19 
 
 f 
 
 6 
 
 4 
 
 33. 
 
 ' 20 
 
 20 
 
 1 
 
 6 
 
 22 
 
 3 
 
 18 
 
 12 
 
 if 
 
 6 
 
 17 
 
 3 f 
 
 16 
 
 16 
 
 ii 
 
 5 
 
 13 
 
 33- 
 
 15 
 
 3 
 
 
 5 
 
 9 
 
 31 
 
 13 
 
 21 
 
 4 
 
 5 
 
 5 
 
 4 
 
 12 
 
 19 
 
 if 
 
 5 
 
 
 
 41. 
 
 11 
 
 21 
 
 it 
 
 4 
 
 21 
 
 40. 
 
 11 
 
 2 
 
 H 
 
 4 
 
 18 
 
 41 
 
 10 
 
 10 
 
 2 
 
 4 
 
 15 
 
 4- 
 
 9 
 
 19 
 
 2| 
 
 4 
 
 12 
 
 4f 
 
 9 
 
 6 
 
 
 4 
 
 9 
 
 4J 
 
 8 
 
 18 
 
 2 1 
 
 4 
 
 6 
 
 47. 
 
 8 
 
 6 
 
 2 i 
 
 4 
 
 4 
 
 5" 
 
 7 
 
 22 
 
 
 

 
 HYDROMETERS. 467 
 
 HYDROMETERS. 
 
 THE following Table shows the correspondence between 
 Beaume, Twedale, and specific gravity; and no doubt 
 will prove useful to dyers, colourers, calico printers, aud 
 bleachers. 
 
 TWED ALE'S HYDROMETER. 
 
 This instrument is in form and principle the same as 
 Beaume's hydrometer for salts, except in the gradation. It 
 takes cognizance only of liquids whose specific gravity 
 exceeds that of water. Its zero is water at 60 degrees, 
 and the space between and 1.S50 (^formerly regarded as 
 the specific gravity of concentrated sulphuric acid,) is di- 
 vided into 170 equal parts. It is in almost universal use 
 among the practical chemists^ calico printers, dyers, aud 
 bleachers, in England, Ireland, Scotland, and America. 
 Its numbers are arranged on six glasses, which are called 
 a whole set, (as the workmen term them.) No. 1 reach- 
 es to 24, No. 2 to 48, No. 3 to 74, No. 4 to 102, No. 5 
 to 138, No. 6 to 170. 
 
 BEAUME'S HYDROMETER. 
 
 There are two hydrometers which have been brought 
 into use by Beaume, a chemical manufacturer of Paris, 
 which are of easy construction, a point to which Beaume 
 was particularly attentive in all his apparatus. Benume'a 
 hydrometer for salts is sometimes used amongst the calico 
 printers, bleachers. &c.; and I have often wondered why 
 it was not more generally adopted, as it answers every pur- 
 pose of Twedale's six glasses. The only objection that 
 can be made against it is, that they cannot arrive at that 
 joint of accuracy which can be come at on Twedale's ; 
 even this objection is groundless, providing a little 
 care is exercised in ascertaining the strength of liquids. 
 The following table will show the correspondence between 
 Beaume, Twedale, and specific gravity, which may prove 
 to be of practical utility. 
 
 poi 
 but
 
 468 
 
 HYDROMETERS. 
 
 Uteyume. 
 
 Twedale 
 
 Specific 
 Gravity. 
 
 Beaume. 
 
 Twedale 
 
 Specific 
 Gravity. 
 
 
 
 
 
 1.000 
 
 38 
 
 72 
 
 1.359 
 
 1 
 
 H 
 
 1.007 
 
 39 
 
 74! 
 
 1.372 
 
 2 
 
 
 1.014 
 
 40 
 
 77! 
 
 1.384 
 
 3 
 
 3* 
 
 1.022 
 
 41 
 
 80! 
 
 1.398 
 
 4 
 
 5! 
 
 1.029 
 
 42 
 
 82* 
 
 1.412 
 
 5 
 
 6f 
 
 1.036 
 
 43 
 
 
 1.426 
 
 6 
 
 8 
 
 1.044 
 
 44 
 
 8t>! 
 
 1.440 
 
 7 
 
 9* 
 
 1.052 
 
 45 
 
 91 
 
 1.454 
 
 8 
 
 
 1.060 
 
 46 
 
 94! 
 
 1.470 
 
 9 
 
 12 3 - 
 
 1.067 
 
 47 
 
 97 
 
 1.485 
 
 10 
 
 14! 
 
 1.075 
 
 48 
 
 100 
 
 1.501 
 
 . 11 
 
 16! 
 
 1.083 
 
 49 
 
 103! 
 
 1.526 
 
 12 
 
 18 
 
 1.091 
 
 50 
 
 1C6! 
 
 1.532 
 
 ; 13 
 14 
 
 19! 
 21! 
 
 1.100 
 1.108 
 
 51 
 52 
 
 109! 
 
 112* 
 
 1.549 
 .1.666 
 
 15 
 
 23 
 
 1.116 
 
 53 
 
 
 1.583 
 
 16 
 
 24! 
 
 7 125 
 
 54 
 
 118! 
 
 1.601 
 
 17 
 
 26! 
 
 1.134 
 
 55 
 
 123 
 
 1.618 
 
 18 
 
 28 
 
 1.143 
 
 56 
 
 127! 
 
 1.637 
 
 19 
 
 30 
 
 1.152 
 
 57 
 
 131* 
 
 1.656 
 
 20 
 
 32 
 
 1.161 
 
 58 
 
 136! 
 
 1 676 
 
 21 
 
 34 
 
 1.171 
 
 59 
 
 139! 
 
 1.695 
 
 22 
 
 36 
 
 1.180 
 
 60 
 
 142! 
 
 1.714 
 
 23 
 
 38 
 
 1.190 
 
 61 
 
 147! 
 
 1.736 
 
 24 
 
 40 
 
 1.199 
 
 62 
 
 151f 
 
 1.758 
 
 25 
 
 42 
 
 1.210 
 
 63 
 
 155* 
 
 1.779 
 
 26 
 
 44 
 
 1.221 
 
 64 
 
 160! 
 
 1.801 
 
 27 
 
 46 
 
 1.231 
 
 65 
 
 165! 
 
 1.823 
 
 28 
 
 48 
 
 1.242 
 
 66 
 
 170 
 
 1.847 
 
 29 
 
 50 
 
 1.252 
 
 67 
 
 
 
 1.872 
 
 30 
 
 52! 
 
 1.261 
 
 68 
 
 
 
 1.897 
 
 31 
 
 54! 
 
 1.275 
 
 69 
 
 
 
 1.921 
 
 32 
 
 56! 
 
 1.2S6 
 
 70 
 
 
 
 1.946 
 
 33 
 
 59 
 
 1.29S 
 
 71 
 
 
 
 1.974 : 
 
 34 
 
 61* 
 
 1.309 
 
 72 
 
 
 
 2.002 ' 
 
 35 
 
 64! 
 
 1.321 
 
 73 
 
 
 
 2.031 
 
 36 
 
 66* 
 
 1.334 
 
 74 
 
 
 
 2.059 
 
 37 
 
 68! 
 
 1.346 
 
 75 
 
 
 
 2.087
 
 APPENDIX 
 
 APPENDIX. 
 
 Form of a Common Negotiable Note. 
 $500 00 
 
 Philadelphia, May 12th, 1839. 
 
 Sixty days after date, I promise to pay to the order oi 
 John Slater, five hundred dollars, without defalcation, for 
 value received. 
 
 Note with Security. 
 8250 00 
 
 Philadelphia, June , 1839 
 
 We, or either of us, promise to pay John Fox, or order, 
 two hundred and fifty dollars, on the ninth day of June, 
 one thousand eight hundred and thirty-nine, for value re- 
 ceived, without defalcation. Witness our hands this 
 day of March, one thousand eight hundred and thirty-nine. 
 JAMES PILKINGTON 
 JAMES ARKWRIGHT. 
 
 Bill of Exchange. 
 $1000 00 
 
 Philadelphia, March 27th, 1839. 
 
 Thirty days after sight, pay to John Brown, or order, 
 this my first bill of exchange, for one thousand dollars, 
 second and third of same tenor and date not being paid, 
 without further advice from 
 
 Your humble servant, 
 
 JOHN GRIEIU 
 
 To John Delany, Esq., New York. 
 40
 
 470 APPENDIX. 
 
 Promissory JYbfe. 
 8250 00 
 
 Philadelphia, Manh 2d, 1839. 
 
 Nine months after date, I promise to pay to Peter Pratt, 
 or order, the sum of two hundred and fifty dollars, foi 
 Yalue received, without defalcation. Witness my ha:id 
 this second day of March, one thousand eight hundred 
 and thirty-nine. GEORGE CAR. ^ 
 
 JVb toitness required. 
 
 JVb/e icith Interest 
 
 I promise to pay John Selby, or order, the sum of three 
 hundred dollars, on demand, with interest till paid, for value 
 received, without defalcation. Witness my hand, this first 
 day of May, one thousand eight hundred and thirty-nine. 
 
 RICHARD BAXTER. 
 
 Form of an Inland Draft for Money, with Acceptance. 
 
 $750 00 
 
 Philadelphia, May 12th, 1839. 
 
 Six months after date, pay to the order of Henry Wild, 
 seven hundred and fifty dollars, for value received, and 
 place the same to my account. JAMES M. BROWN. 
 To Mr. ELF HALL, \ 
 Merchant, > 
 
 Baltimore. ) Accepted, 
 
 ABRAHAM COOK. 
 
 Bill of Lading. 
 
 Shipped, in good order, and well conditioned, by Jabez 
 Hill, on board the called the whereof 
 
 is master, now lying in the port of 
 and bound for to say 
 
 being marked and numbered, as in the margin, and are to 
 bo delivered in the like order and condition, at the port of 
 the dangers of the seas only excepted, unto
 
 APPENDIX. 471 
 
 or to assigns, paying 
 
 'freight for the said with 
 
 primage and average accustomed. 
 
 In witness whereof, the master or mate of the said vessel 
 hath affirmed to bills of lading, all of this tenor 
 
 and date, one of which being accomplished, the others to 
 stand void, dated in the 
 
 day of 183 
 
 Bill of Parcels. 
 Philadelphia, January 30th, 1839. 
 Mr. John Hopkins, 
 
 Bought of James Pilkington, 
 
 2 doz. Domestic shawls, a $2.25 per doz. $4.50 
 2 Silk handkerchiefs 9.50 
 
 5 Double strap suspenders, 2.25 " 
 
 3 " hose, 
 
 1-^ " Fine Penknives, 
 
 2| " Best Razors, 
 33 yds. Domestic muslin, 
 25 Satinet, 
 
 5 pieces Calico, 165 yds., 
 
 $125.G9i 
 
 Receipt General form. 
 
 Philadelphia, April 2d, 1839. 
 
 Received of Mr. Harlan Page, two hundred and seventy 
 dollars, in full, for balance of account 
 
 JOHN NEWTON. 
 
 8270 0~0 
 
 Letter of Credit. 
 Messrs. Carick & Rogers, Gentlemen, 
 
 Allow me to introduce to your firm the bearer, James 
 Pilkington, a gentleman about commencing business. 
 Should he make a selection from your stock to the ainoWj 
 of five hundred dollars, I will be answerable for that sufc 
 in case of his non-payment. With esteem, yours, 
 
 SIMON PIKB,
 
 472 APPENDIX. 
 
 FOREIGN COINS, 
 
 With their value in Federal money. 
 
 A Johannes, - 
 
 A doubloon, ... 
 
 A half Johannes, ... 
 
 A moidore, ... 
 
 An old English guinea, 
 
 A French guinea, 
 
 An English sovereign, 
 
 Pound of Ireland, 
 
 A Spanish pistole, - 
 
 A French pistole, 
 
 A pound flemish of Amsterdam, 
 
 Pagoda of India, 
 
 A sequin of Arabia, 
 
 An oz of Persia, 
 
 Tale of China, 
 
 Millree of Portugal, 
 
 English or French crown, 
 
 Dollar of Spain, 
 
 Rix dollar of Sweden, 
 
 Rix dollar of Denmark, 
 
 Scudo of Rome, 
 
 A ducat of Naples, 
 
 Ruble of Russia, ... 
 
 Rupee of Bengal, 
 
 A florin of Yienna, 
 
 Guilder of Holland, - 
 
 Marc banco of Hamburg, 
 
 Piastre of Constantinople, - 
 
 An English shilling, 
 
 A Pistareen, ... 
 
 Jjivre tournois of France, 
 
 A fame, .... 
 
 A lira of Florence, 
 
 Real of Spain, ... 
 
 
 U. c m 
 16 00 
 14 93 
 
 8 00 
 
 00 
 
 66 6 
 
 60 
 
 44 4 
 
 10 2 
 
 3 77 7 
 
 3 66 6 
 
 2 42 7 
 
 94 
 
 66 6 
 
 48 2 
 
 48 
 
 27 3 
 
 10 
 
 00 
 02 5 
 
 01 3 
 96 
 75 5 
 71 3 
 55 5 
 46 6 
 39 
 S3 3 
 24 3 
 22 2 
 20 
 17 6 
 17 9 
 16 
 
 9 1
 
 APPENDIX.. 
 
 473 
 
 STERLING MONEY, 
 
 WUh the par value in dollars, cents and mills. 
 
 Sterling. ^| 
 
 
 United States. 
 
 , s.d. 
 
 
 $ cts. m. 
 
 1 
 
 
 1 8 
 
 2 
 
 
 3 7 
 
 3 
 
 
 5 5 
 
 4 
 
 
 7 4 
 
 5 
 
 
 9 2 
 
 6 
 
 
 11 1 
 
 7 
 
 
 12 9 
 
 8 
 
 
 14 8 
 
 9 
 
 
 16 6 
 
 10 
 
 
 18 5 
 
 11 
 
 
 20 3 
 
 1 
 
 
 22 2 
 
 1 6 
 
 
 33 3 
 
 2 
 
 _o 
 
 44 4 
 
 2 6 
 
 >ri 
 
 fc. '/; 55 5 
 
 3 
 
 < 
 
 66 6 
 
 3 6 
 
 
 77 7 
 
 4 
 
 
 88 8 
 
 4 6 
 
 
 00 
 
 5 
 
 
 11 1 
 
 6 6 
 
 
 22 2 
 
 6 
 
 
 33 3 
 
 6 6 
 
 
 44 4 
 
 7 
 
 
 55 5 
 
 7 6 
 
 
 66 6 
 
 8 
 
 
 77 7 
 
 8 6 
 
 
 88 8 
 
 9 
 
 
 2 00 
 
 9 6 
 
 
 2 11 1 
 
 10 
 
 
 2 22 2 
 
 20 
 
 
 4 44 4 
 
 40
 
 474 
 
 APPENDIX. 
 
 Sterling. ' 
 
 
 United States. 
 
 s.d. 
 
 
 Dolls, els. m. 
 
 10 
 
 
 44 44 4 
 
 20 
 
 
 88 88 8 
 
 30 
 
 _o 
 
 133 33 3 
 
 40 
 
 >"< 
 
 '77 77 7 
 
 50 
 
 
 222 22 2 
 
 100 
 
 r 
 
 444 44 4 
 
 500 
 
 
 2,222 22 2 
 
 1,000 
 
 
 4,444 44 4 
 
 5,000 
 
 
 22,222 22 2 
 
 10,000 0. 
 
 
 j 44,444 44 4 
 
 DOLLARS AND CENTS, 
 
 ITilh their par value in English money. 
 
 Dolls, els. ' 
 
 
 r ' *. d. 
 
 50 
 
 
 2 3 
 
 60 
 
 
 2 8 
 
 70 
 
 
 3 1 
 
 80 
 
 
 3 7 
 
 90 
 
 
 4 
 
 1 00 
 
 
 4 6 
 
 2 00 
 
 
 9 
 
 3 00 
 
 
 13 6 
 
 4 00 
 
 o 
 
 18 
 
 5 00 
 
 10 00 
 
 T 
 
 1 2 6 
 
 260 
 
 20 00 
 
 r 
 
 4 10 
 
 30 00 
 
 
 6 15 
 
 40 00 
 
 
 900 
 
 50 00 
 
 
 1150 
 
 100 00 
 
 
 22 10 
 
 500 00 
 
 
 112 10 
 
 1,000 00 
 
 
 225 
 
 5,000 00 
 
 
 1,125 
 
 10,000 00 
 
 
 2,250 
 
 60,000 00 
 
 
 . 11,250
 
 476 APPENDIX. 
 
 No. 1. No. 2. 
 
 No. 3. 
 
 No. 5. 
 
 No. 4. 
 
 No. 6.
 
 APPENDIX. 477 
 
 No. 7. No. 8. 
 
 No. 9. 
 
 No. 11. 
 
 No. 10. 
 
 No. 12.
 
 478 APPENDIX. 
 
 No. 13. No. 14. 
 
 No. 15. 
 
 No. 16.
 
 APPENDIX. 479 
 
 MECHANICAL MOVEMENTS. 
 
 No. 1, 
 
 Is the ingenious contrivance of the celebrated Montgol. 
 fier, generally called thehydraulic ram. In this apparatus, 
 a current of water must flow through the tube, iu the direc- 
 tiou of the arrow, and escape at the lower valve which is 
 kept open by a weight or spring, calculated according to 
 the current ; so that when the current arrives at its spued, 
 this valve is closed, and the momentum which the water 
 has acquired, forces open the upper valve which leads to 
 an air chamber above, where the portion of the water which 
 has passed the valve is received, and thence conducted iu 
 any required direction. As soon as the water which pass- 
 es through the upper valve has come to a state of equilib- 
 rium, the stream at the arrow is necessarily at rest, and the 
 lower valve is again opened by the spring or weight, at the 
 same time that the valve leading to the air vessel is shut ; 
 thus by the alternate action of the two valves a portion o* 
 the stream is raised at every stroke, and carried to a reser- 
 voir above. 
 
 No. 2 
 
 Represents a section of the oscillating column invented 
 by M. Mannoury d' Ectot, for the purpose of elevating a 
 portion of a given fall of water, above the level of the 
 reservoir or head by means of a machine, all the parts ot 
 which are absolutely fixed. It consists of an upper or 
 smaller tube which is constantly supplied with water, and 
 the lower or larger tube constructed with a circular plate in 
 the centre of the office, which receives the stream from the 
 tube above. Upon allowing the water to descend it forms 
 itself gradually into a cone on the circular plate, whicn 
 cone protrudes into the smaller tube, so as to stop th6 flow 
 of water downwards, and the regular supply continuing 
 from above, the column in the upper tube rises until the 
 cone on the circular plate gives way ; this action is re- 
 newed periodically, and is regulated by the supply of water,
 
 480 APPENDIX. 
 
 No. 3 and 4,^ 
 
 Are horizontal, and overshot water wheels. 
 
 No. 5, O 
 
 Represents a revolving perpendicular shaft, carrying 
 two balls which vibrate on levers, supported on a common 
 centre above ; these balls beiug.acted on by the centrifugal 
 force, fly out according to the velocity of the shaft. On 
 the upper part of the shaft is placed a loose collar, con- 
 nected to the opposite ends of the levers which carry the 
 two balls, which by their position either elevate or depress 
 the loose collar, and regulate the valve on the right, with 
 which it is connected this arrangement is generally used 
 to regulate the supply of steam to engines. 
 
 No. 6, 
 
 Is an application of the governor for regulating the sup- 
 ply of water to wheels. The horizontal wheel is fixed to 
 the revolving shaft, which receives motion from the water 
 wheel, the speed of which is calculated to place the balls 
 in the position here represented ; but should it increase 
 and thereby raise the sliding piece, a projection from the 
 left of the shaft would strike against the part immediately 
 above, and traverse the coupliug on the horizontal shaft 
 below, into gear with the left hand bevil, which being con- 
 nected with the shaft, depresses the shuttle of the water 
 wheel, and reduces the speed ; but should the speed go 
 too slow, and the balls collapse, the same projection would 
 strike against the part immediately beneath it, and the 
 bevil on the right would be connected with the shaft and 
 turn it in an opposite direction, thereby raising the shuttle 
 for a greater supply of water. 
 
 No. 7. 
 
 This is an useful governor for pumping engines, in which 
 the work is suddenly varied. The solid piston here repre- 
 sented does not fit tight to the cylinder, which being filled 
 with water is compelled to escape through the space, when
 
 ?NDIX. 481 
 
 the passage 011 the^ight hand is shut, and thus work is 
 thrown on the engine ; but supposing the governor to re- 
 sume its proper position, the valve in this side passage la 
 opened, and the piston traverses without resistance. 
 
 No. 8 and 9. 
 
 Two arrangements for producing circular motion, by 
 the hands or feet. 
 
 No. 10, 
 
 Is the universal joint generally attributed to Dr. Hock, 
 by means of which the rotary motion of a shaft may be 
 conveyed out of the straight line, without breaking its 
 continuity. 
 
 No. 11 
 
 Is an arrangement of spur wheels running loose on thefr 
 respective shafts, with which they can be connected by 
 clutch boxes, so that the relative speed of the driver and 
 the driven can be varied according to the proportion of the 
 wheels which are connected to the shafts. 
 
 No. 12, 
 
 Is a combination of wheels running loose on their re- 
 spective shafts, which will produce a variety of speeds in 
 a similar manner to the oneTast mentioned. 
 
 No. 13. 
 
 Supposing the upper circle to represent a section of two 
 drums close to each other, and running in opposite direc- 
 tions, the endless band which passes over the carrier pulley, 
 below, will impart motion to the horizontal warve at the 
 lower end of the perpendicular screw, which is supported 
 by the upper and lower arms, but carries the central pieces 
 as a moveable nut ; to this nut is connected a fork, which 
 at each extreme of its traverse vibrates the weighted lever, 
 and thereby passes the endless band from one drum to the 
 other, and reverses the revolution of the screw. 
 41 2F
 
 482 APPENDIX. 
 
 No. 14, * 
 
 Is a machine proposed by M. Grandjean for cutting 
 screws, in which the piece to be cut is traversed, by meana 
 of the bent lever on the left, which is acted on by the same 
 treadle which gives the rotary motion. *. 
 
 No. 15, 
 
 Represents a machine for driving piles, in which the 
 circular motion of the central perpendicular shaft is con- 
 verted into alternate perpendicular motion, in the weight 
 on the left. The principal contrivance by which the weight 
 is relieved when at its highest elevation, is effected by the 
 progressive increase of the coils of rope on the central 
 shaft, which press on a small lever seen to the right hand, 
 and disengages the upper part of the shaft, and allows the 
 weight to run down ; the upper part of the shaft being, 
 again re-connected as soon as the rope has run off. 
 
 No. 16. 
 
 Suppose the upper part of this figure to represent the 
 sails of an horizontal mill, or any sufficient moving power 
 to revolve the shaft which carries the spiral or worm below, 
 and the shaft coupled immediately below the sails so as to 
 allow a small vibration, thereby allowing thespiral or worm, 
 to act on only one wheel at a time. At the back of these 
 wheels and on the same shafts are placed pulleys, over 
 which a rope is passed, carrying a bucket at each extremi- 
 ty, one of which is elevated at the same time that the other 
 is lowered, by the alternative action of the worm on the 
 opposite wheels. In the centre, and immediately below 
 the worm is placed a vibrating piece, against which the 
 bucket strikes in its ascent, and which, by means of an 
 arm connected with the step in which the worm shaft is 
 supported, traverses the worm from one wheel to the other, 
 by which means the bucket which has delivered its water 
 is again lowered, at the same time that the opposite oiie ii 
 elevated.
 
 INDEX. 
 
 \cetates 
 
 .Page 219 
 219 
 
 
 . 189 
 
 ^h s'l us 
 
 188 
 
 
 219 
 
 P P 
 
 188 
 
 
 . . . 220 
 
 P ,. 
 
 190 
 
 of copper . . . 
 
 220 
 45 
 
 
 193 
 
 
 .. 193 
 
 Acids 
 
 156 
 
 Li" ic ' 
 
 .... 193 
 
 
 157 
 
 , sc ji n i c 
 
 194 
 
 acetic 
 
 . 157 
 
 
 . 194 
 
 
 159 
 
 s r ! c 
 
 sane . 
 
 ... 196 
 
 
 . ... 159 
 
 U 
 
 196 
 
 
 158 
 
 
 196 
 
 
 160 
 
 
 197 
 
 
 ... 161 
 
 
 .. 198 
 
 
 . ... 161 
 
 " u P '. irou3 
 
 . ... 199 
 
 
 163 
 
 
 200 
 
 
 163 
 
 
 200 
 
 __ , chloriodic 
 
 .. 164 
 
 lings ic . . 
 
 . ... 201 
 
 
 165 
 
 g- ous 
 
 201 
 
 
 165 
 
 
 201 
 
 
 167 
 
 
 45 
 
 del hini 
 
 167 
 
 
 45 
 
 
 168 
 
 
 18 
 
 
 168 
 
 
 18 83 
 
 gallic 
 
 . 170 
 
 
 18 
 
 
 171 
 
 
 19 
 
 iodic . . 
 
 171 
 
 
 45 
 
 
 172 
 
 Aluming, for dyeing 
 
 354 
 
 
 172 
 
 . 230 242 
 
 lithic 
 
 .. 173 
 
 Alcohol 
 
 85 
 
 
 ..173 
 
 Alloy 
 
 19 
 
 
 ... 174 
 
 Alkalies 
 
 13. 201 
 
 meccuuc 
 
 175 
 
 
 ... 45 
 
 
 175 
 
 
 45 
 
 
 175 
 
 
 249 
 
 menispermic . . 
 
 177 
 177 
 
 
 .. 206 
 
 
 2C 
 
 molybdenous . . 
 
 178 
 
 178 
 
 
 365 
 
 Annetto on col on 
 
 365 
 
 in u ^! c . 
 
 179 
 
 A t' n ~ l 
 
 . . . 140 
 
 nitr' 
 
 .. 180 
 
 
 . 241 
 
 nitrous 
 
 182 
 
 Annealing of steel and iron 2rfl 
 
 nitro-muriatic . . 
 
 183 
 .. 183 
 
 Arsenic 
 
 137 
 
 p luri 
 
 183 
 
 . 
 
 21 
 
 --r- oxalic 
 
 184 
 
 
 81 
 
 32 
 
 
 (483)
 
 484 
 
 INDEX. 
 
 
 270 
 22 
 310 
 
 233 
 46 
 25 
 232 
 135 
 247 
 247 
 356 
 367 
 363 
 370 
 
 3fiO 
 360 
 361 
 322 
 328 
 46 
 243 
 326 
 361 
 356 
 370 
 369 
 369 
 213 
 369 
 
 339 
 243 
 350 
 350 
 218 
 338 
 359 
 359 
 359 
 360 
 355 
 357 
 366 
 365 
 
 26 
 26 
 
 
 4f 
 35$ 
 
 338 
 339 
 26 
 71 
 218 
 217 
 217 
 226 
 246 
 26 
 26 
 26 
 340 
 326 
 344 
 
 344 
 
 327 
 339 
 312 
 312 
 154 
 
 343 
 59 
 11 
 18 
 27 
 320 
 152 
 
 46 
 27 
 147 
 154 
 232 
 27 
 255 
 27 
 31( 
 215 
 298 
 27 
 27 
 27 
 329 
 323 
 
 Atoms 
 
 Ca idles, imitation of wax . . . 
 Caoutchouc, or India rubber 
 how dissolved . . 
 its uses 
 Carburet . 
 
 Attraction . . 23 
 
 B. 
 Balsams 
 
 
 Carbon . . . . 
 
 Basis 
 
 
 
 ar ona es . .... 
 
 Bismuth 
 
 
 
 Ca b "* C 'd 
 
 Bituminous substances 
 Black on silk 
 
 Cartilage 
 
 Caustic 
 
 
 Cawk 
 
 
 
 
 Cement, block-cutters 
 fire and waterproof . 
 elastic, for belts . . . 
 
 on woollen inclining to 
 nurnle ........ 
 
 
 
 
 
 
 orcas iron pipes an 
 
 - B^ 1-n ^' 6 
 
 
 Blood P ** 
 
 
 Blue ink 
 
 
 prussian, on woollen. . . 
 on silk 355 
 
 
 Cloth, to render wind and 
 
 on ea er 
 
 
 Chemical apparatus 
 
 on ra jj cn 
 
 
 
 - vat for cotton 
 
 Chlorate 
 
 Boots and shoes, to render 
 
 
 
 Rnnps 
 
 
 
 
 to dye and colour 
 Borates 
 
 
 Cobalt 
 
 
 
 onzing . . 
 on woo e 
 
 Colouring 1 matter 
 
 
 red cast . 
 
 
 ' inclining to snuff 
 
 
 
 n E -it 'A 
 
 
 on silk dress , 
 
 
 on cotton 
 
 Concentration 
 
 G 
 
 
 Copal, to dissolve in alcohol 
 in turpentine 

 
 INDEX. 
 
 485 
 
 Jopal, to dissolve in fixed oil . 
 Copper 115 
 
 331 
 
 283 
 348 
 358 
 202 
 46 
 251 
 28 
 46 
 46 
 
 28 
 28 
 28 
 29 
 29 
 29 
 29 
 29 
 
 298 
 29 
 29 
 29 
 29 
 47 
 29 
 29 
 358 
 358 
 362 
 366 
 351 
 353 
 368 
 
 349 
 30 
 30 
 30 
 30 
 258 
 30 
 30 
 30 
 30 
 .87 
 47 
 
 
 
 Corks for bottles 
 
 Extract 30 
 
 Cr* n 
 
 F. 
 
 Crucible . .... 
 
 
 
 Fibrin . 242 
 
 
 Filteration 31 
 
 Cupel 
 
 Fire and waterproof cement 326 
 Fixed 32 
 
 D. 
 
 Decantation 
 
 Fluate 32 
 
 Fluates . 207 
 
 
 Flesh colour on silk 358 
 
 
 Fluate of lime 218 
 
 
 of si lex 218 
 
 Defla *ratio 
 
 Fluid . . 32 
 
 
 Fl ux 32 
 
 
 Fluxion 32 
 
 Dephlogisticated . . . . 
 Description of the lii>es of 
 
 Fly wheels 317 
 
 
 
 
 Fusion 33 
 
 
 
 
 G. 
 Galvanism 261 
 
 nv n f lon " 
 
 Digester 
 
 Distillation 
 
 Gas 33 84 
 
 
 
 o e on si 
 
 
 
 Gelatine 30 
 
 n S \- lien 
 
 Gilding 340 
 
 
 on calf and sheep-skin 348 
 Glauber's salts 211 
 
 
 
 Gloss, to put on silk .... 367. 368 
 Glue . ... 246. 296 
 
 
 E. 
 
 method of preparing 
 
 Gluten . a " ?. . 230 
 
 Ebullition 
 Effervescence .... *....; 
 
 Gold 96 
 
 to dye on silver medals 
 and lamellas through. 
 
 Elastic 
 
 Electricity 
 
 Graver's improved aiethod of 
 
 
 iqua ion 
 
 
 Essence 
 
 
 Etherial 
 
 Green on cotton .. . , 364 
 Green sulphate of iron 21 
 Grev on silk 357 
 
 Ether 

 
 486 
 
 INDEX. 
 
 British 236 
 CopaJ 236 
 
 
 33 
 
 33 
 
 23!) 
 
 37C 
 
 34 
 312 
 
 58 
 362 
 
 31 
 
 34 
 
 34 
 
 3G9 
 34 
 262 
 150 
 309 
 356 
 3ti5 
 34 
 273 
 
 317 
 309 
 34 
 100 
 227 
 88 
 344 
 244 
 318 
 34 
 311 
 34 
 356 
 49 
 233 
 49 
 215 
 215 
 215 
 21(i 
 
 lac 237 
 Senegal 235 
 
 Lead 106. 
 Leather, different shades of 
 
 
 
 
 H. 
 
 
 Light 
 
 Lilac on woollen 
 
 Honey . 232 
 
 Liquors, scalding and prepar- 
 ing for dyers 
 
 Hands, easy method of clean- 
 ing 346 
 
 
 Horn 243 
 
 
 Horn to soften 345 
 
 M. 
 Maceration 
 
 
 
 
 
 Madder, French, how marked 
 according to quality 
 
 Hyper-oxy muriate of potass .. 216 
 
 I. 
 Ide . 33 
 
 
 
 Inclined plane 315 
 
 Matter 
 
 
 
 
 
 
 Martial 
 
 Ink black 325 
 
 
 blue . ... . 326 
 
 Men and horses, considered as 
 
 - red i 326 
 
 Indian or China 342 
 
 
 Ink powder 347 
 
 
 
 Mercury 
 
 -vats 369 
 
 Metallic oxides 
 
 lodate 33 
 
 Metals 
 
 Iodide ... 33 
 
 Mildew, to remove from linen 
 Milk 
 
 Iron, to prevent from rustin? 347 
 to give a temper to cut 
 
 Mill-work 
 
 
 Iron 118273 
 
 
 
 
 Ivory to soften 349 
 
 Maroon dyeing on silk 
 
 Mortar 
 
 dyeing 342 349 
 
 to whiten and polish . . 350 
 
 J. 
 Japanning- 333 
 
 
 Muffles 
 
 of soda . 
 
 
 work oolishingr . . . . 334 

 
 
 INDEX. 
 
 487 
 
 Narcotic principle 231 
 
 Portable balls for taking spots 
 
 342 
 
 203 
 208 
 36 
 354 
 37 
 222 
 223 
 314 
 371 
 366 
 37 
 317 
 239 
 49 
 
 37 
 37 
 37 
 
 40 
 53 
 212 
 326 
 365 
 369 
 370 
 362 
 41 
 s 56 
 311 
 41 
 233 
 53 
 146 
 41 
 249 
 
 42 
 42 
 339 
 216 
 42 
 202 
 209 
 213 
 42 
 49 
 
 
 Neutralisation 34 
 
 Potassium 
 
 ickel ]13 
 
 Pnf.ij . 
 
 Nitrates 213 Pntash 
 
 
 P ' 'tat' 
 
 of soda 214 
 
 Preparation of dye liquors. . . 
 
 
 
 0. 
 Of substances 57 
 Oil, 1 oz. of which will last as 
 long as 1 Ib. of any other. . 348 
 Oil to prevent smoking in lamps 342 
 Oil to prevent pictures from 
 becoming black 348 
 
 Prussiate of potass and iron. . 
 Pulley . 
 
 
 
 Putrefaction 
 
 Pyrites 
 
 Pyroligneous tar 
 
 Oil, to extract from any flower 352 
 
 R. 
 Radical 
 
 Olive oil silk * 357 
 
 Optics 267 
 
 Rancidity 
 
 
 
 on woollen 363 
 
 
 Organic substances 228 
 
 
 
 Oxides 35 223 
 
 Red ink 
 
 
 
 
 
 Oxyiode 35 
 
 Turkey on leather 
 
 
 Oxides of nitrogen 224 
 of hydrogen 2'^fi 
 
 
 Remarks on chemical apparati 
 
 of sulphur 226 
 of phosphorus 226 
 
 P. 
 
 
 
 Retorts 
 
 Palladium 104 
 
 
 Pearl-ash 208 
 
 Rosin, brown and yellow 
 S. 
 
 1 Sol 
 
 
 
 Phlogiston 36 Salifiable 
 
 Phosphates 36. 221 | Sal ammoniac 
 
 
 s r d t 
 
 r r o 222 
 
 
 
 
 Pitch 239 
 
 
 
 Sediment
 
 INDEX. 
 
 Simple . . 42 
 
 Titanium 152 
 
 Silver 109 
 
 Tortoise-shell, preparation for 350 
 
 Slate on silk 357 
 
 Trituration ... 44 
 
 
 Tungsten 145 
 
 on woollen . 363 
 
 
 Silver, to write on 351 
 Slide rule 204 
 
 U. 
 Undulations, to make on -wood 349 
 
 Soda 204 
 Soda water to make 344 
 
 V.* 
 
 Sodium . . 132 
 
 Viscidity 45 
 
 Soldering 293 
 
 
 - of ferrules 93 
 
 a variety 329 
 
 
 copal 329 
 
 Space 310 
 
 
 Specific gravity .... 43 
 
 to gild with without gold 332 
 
 Spirit . .43 
 
 
 
 tis 332 
 
 Stratification 43 
 
 
 Starch 229 
 
 
 Steel blueing of . 280 
 
 
 Stone colour on silk . . 357 
 
 
 Sub 43 
 
 seed-lac 331 
 
 
 Vegetables 228 
 
 Suborate of soda 218 
 Sub carbonate of soda . . . 217 
 
 Vinegar, to increase strength of 351 
 
 
 portable 353 
 
 Sugar 229 
 
 
 of lead 220 
 
 
 Sulphur 70 
 Sulphate of alumine 210 
 
 W. 
 Water 78 
 
 of indigo 355 
 
 of copper 213 
 of soda 211 
 
 Wax 231 
 dry 45 
 humid 45 
 Wedge 315 
 
 Sulphites 213 
 Super 44 
 Super-tartrate of potass 220 
 
 T. 
 
 Table of saline products 202 
 
 Wheel-carriages 319 
 Wheel and axle 314 
 White-wash that will not rub off 345 
 Wine, to restore that is sour . 351 
 to correct the bid taste 3f> 1 
 Woody fibre 232 
 
 rule 299 
 
 Wood to dye red 348 
 
 Tantalium 151 
 
 ._ to petrify . . 350 
 
 Tanning. . 231 
 
 
 Tartrates * 220 
 
 y. 
 
 of potass and soda. . . 221 
 
 - on leather 370 
 
 . of potass and antimony 221 
 Tar.. .*>;......,* 238 
 
 on silk 358 
 
 Tellurium 144 
 Thermometer ... .53 
 
 Z.
 
 
 INDEX TO SUPPLEME 
 
 NT. 
 
 toff* 
 
 Air Pump -f t tvt . . 333 
 
 Application of Specific Gravity " ',- \ -^.; - - 421 
 
 Appendix ... '"..":. i,. . 469 
 
 Beaume's Hydrometer - * - - . - 467 
 
 Banks on Mills ...... 394 
 
 Bodies, Resistance of, when pressed longitudinally - . 409 
 Bricklayers' Work ..... 432 433 
 
 Building ....... 426 
 
 Circles and Diameters - - ^^, ^j-.*. - 434 
 
 Cold Water Pump - -' <>k> ." -;'. ,'. ' - 383 
 
 Communication of Power .... 393 
 
 Condenser ....... 333 
 
 Diameters and Circumferences .... 435 
 
 Engine Powers, to calculate ..... 331 
 
 Examples on the Strength of Materials - - - 410 
 
 Floors, Laying, Jointing, &c. ... . 426 
 
 Fly Wheels 385 
 
 Governor or Double Pendulum .... 336 
 
 Hot water Pump - ... . . . 334 
 
 Manager's Assistant in a Cotton Mill - - - 443 
 
 Materials, Strength of - .... 407 
 
 Mill Work - - 405 
 
 Overshot Wheel 393 
 
 Parallel Motion - * 386 
 
 Power and Effect ...... 395 
 
 Power, Communication of ----- 398 
 
 Pumps ....... 399 
 
 Steam Boilers - _. .- - - - - 376 
 
 Steam Engine - ... 375 
 
 " " rendered easy - - 436 
 
 Force and Heat of 388 
 
 Specific Gravity of Metals, Stones, Earths, Resins. Liquors, 
 
 and Woods - - . . 418-420 
 
 u " compared with Beaume and Twedale's 
 
 Hydrometer Scale ... 468
 
 
 
 490 + INDEX TO SUPPLEMENT. 
 
 Table showing the square inch of the Area of the Safety 
 Valve; also, feet of Vertical Height of Feed Pipe, 
 
 measured from the water line in the boiler - - 377 
 
 " of degrees of Heat, Libs, of Pressure on the Safety 
 
 Valve .... 373 
 
 u showing the Effective Pressure in each inch of the 
 Piston, the Area equal to what one horse power 
 
 will be ...... 382 
 
 e Showing the Force and Heat of Steam 38f 
 " Showing the Height of a Fall of Water in feet, the 
 
 Time of falling in seconds - - - - 39L 
 
 of Mill Work ..... 405 
 
 u showing the Relative Force of Overshot Wheels, 
 
 Steam Engines, Horses, Men and Wind Mills - 406 
 
 " showing Strength of Materials 414 
 " showing the Relative Weight that may be borne by 
 
 different materials ..... 408 
 
 " of Sizes and Strength of Chains ... 414 
 of Specific Gravities of different Bodies - 415 418 
 " of Weight of a Square foot of Cast and Malleable 
 
 Iron, Copper, and Lead .... 416 
 
 u of the Weight of a Lineal Foot of Malleable and Cast 
 
 Iron Bars - - - - - - 417 
 
 " of the Properties of different Bodies - - 422 
 
 " of the Weight of Cast Iron Pipes - - - 423 
 
 " of Boring and Turning .... 425 
 
 " of the Proportions of Timbers for small and large 
 
 buildings ..... 428429 
 
 " of Bricklayers' Work ..... 432 
 
 " for ascertaining Circles and Diameters - - 435 
 
 The Power of Steam Engines, and the method of com put 
 
 ing it - - - - - - 387 
 
 Timbers, Proportions of, for large and small buildings 428 
 
 Turning and Boring ..... 425 
 
 Twedale's Hydrometer - - - - .487 
 
 Undershot Wheels ..... 403 
 
 Velocity of Water Wheel ..... 395 
 
 Watei ....... 391 
 
 Watek Wheel ..... 3S9 393 
 
 " Pressure ...... 389 
 
 " Wheel, Height of ..... 395 
 
 *..- " Velocity of 39 
 
 - " Number of Buckets - - - - 397
 
 
 - 
 
 

 
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