Elements of Chemistry

Antoine Lavoisier

• Publisher: Dover Publications
• Year: 2011
• ISBN:
  9780486141251
• Topic: Physical Sciences
• Subtopic: Chemistry
• Index: Chemistry

The debt of modern chemistry to Antoine Lavoisier (1743–1794) is incalculable. With Lavoisier's discoveries of the compositions of air and water (he gave the world the term 'oxygen') and his analysis of the process of combustion, he was able to bury once and for all the then prevalent phlogiston doctrine. He also recognized chemical elements as the ultimate residues of chemical analysis and, with others, worked out the beginnings of the modern system of nomenclature. His premature death at the hands of a Revolutionary tribunal is undoubtedly one of the saddest losses in the history of science.
Lavoisier's theories were promulgated widely by a work he published in 1789: Traité élémentaire de Chimie. The famous English translation by Robert Kerr was issued a year later. Incorporating the notions of the "new chemistry, " the book carefully describes the experiments and reasoning which led Lavoisier to his conclusions, conclusions which were generally accepted by the scientific community almost immediately. It is not too much to claim that Lavoisier's Traité did for chemistry what Newton's Principia did for physics, and that Lavoisier founded modern chemistry.
Part One of the Traité covers the composition of the atmosphere and water, and related experiments, one of which (on vinous fermentation) permits Lavoisier to make the first explicit statement of the law of the conservation of matter in chemical change. The second part deals with the compounds of acids with various bases, giving extensive tables of compounds. Its most significant item, however, is the table of simple substances or elements — the first modern list of the chemical elements. The third section of the book reviews in minute detail the apparatus and instruments of chemistry and their uses. Some of these instruments, etc. are illustrated in the section of plates at the end.
This new facsimile edition is enhanced by an introductory essay by Douglas McKie, University College London, one of the world's most eminent historians of science. Prof. McKie gives an excellent survey of historical developments in chemistry leading up to the Traité, Lavoisier's major contributions, his work in other fields, and offers a critical evaluation of the importance of this book and Lavoisier's role in the history of chemistry. This new essay helps to make this an authoritative, contemporary English-language edition of one of the supreme classics of science.

ELEMENTS

or

CHEMISTRY.

PART I.

Of the Formation and Decomposition of Aeriform Fluids—of the Combuſtion of Simple Bodies— and the Formation of Acids.

CHAP. I.

Of the Combinations of Caloric, and the Formation of Elqſtic Aëriform Fluids.

THAT every body, whether ſolid or ſluid, is augmented in all its dimenſions by any increaſe of its ſenſible heat, was long ago fully eſtabliſhed as a phyſical axiom, or univerſal propoſition, by the celebrated Boerhaave. Such fac‍ts as have been adduced for controverting the generality of this principle offer only fallacious reſults, or, at leaſt, ſuch as are ſo complicated with foreign circumſtances as to miſlead the judgment; But, when we ſeparately conſider the effec‍ts, ſo as to deduce each from the cauſe to which they ſeparately belong, it iſ eaſy to perceive that the ſeparation of particles by heat is a conſtant and general law of nature.

When we have heated a ſolid body to a certain degree, and have thereby cauſed its particles to ſeparate from each other, if we allow the body to cool, its particles again approach each other in the ſame proportion in which they were ſeparated by the increaſed temperature; the body returns through the ſame degrees of expanſion which it before extended through ; and, if it be brought back to the ſame temperature from which we ſet out at the commencement of the experiment, it recovers exac‍tly the ſame dimenſions which it formerly occupied. But, as we are ſtill very far from being able to arrive at the degree of abſolute cold, or deprivation of all hear, being unacquainted with any degree of coldneſs which we cannot ſuppoſe capable of ſtill farther augmentation, it follows, that we are ſtill incapable of cauſing the ultimate particles of bodies to approach each other as near as is poſſible; and, conſequently, that the particles of all bodies do not touch each other in any ſtate hitherto known, which, tho’ a very ſingular concluſion, is yet impoſſible to be denied.

It is ſuppoſed, that, ſince the particles of bodies are thus continually impelled by heat to ſeparate from each other, they would have no connec‍tion between themſelves ; and, of conſequence, that there could be no ſolidity in nature, unleſs they were held together by ſome other power which tends to unite them, and, ſo to ſpeak, to chain them together; which power, whatever be its cauſe, or manner of operation, we name Attrac‍tion.

Thus the particles of all bodies may be conſidered as fubjec‍ted to the ac‍tion of two oppoſite powers, the one repulſive, the other attrac‍tive, between which they remain in equilibrio. So long as the attrac‍tive force remains ſtronger, the body muſt continue in a ſtate of ſolidity ; but if, on the contrary, heat has ſo far removed theſe particles from each other, as to place them beyond the ſphere of attrac‍tion, they loſe the adheſion they before had with each other, and the body ceaſes to be folid.

Water gives us a regular and conſtant example of theſe fac‍ts ; whilſt below Zero * of the French thermometer, or 32° of Fahrenheit, it remains ſolid, and is called ice. Above that degree of temperature, its particles being no longer held together by reciprocal attrac‍tion, it becomes liquid ; and, when we raife its temperature above 80°, (212°) its particles, giving way to the repulſion cauſed by the heat, aſſume the ſtate of vapour or gas, and the water is changed into an aëriform fluid.

The ſame may be affirmed of all bodies in nature: They are either ſolid or liquid, or in the ſtate of elaſtic aëriform vapour, according to the proportion which takes place between the attarc‍tive force inherent in their particles, and the repulſive power of the heat ac‍ting upon-theſe; or, what amounts to the ſame thing, in proportion to the degree of heat to which they are expoſed,

It is difficult to comprehend theſe phenomena, without admitting them as the effec‍ts of a real and material ſubſtance, or very ſubtile fluid, which, inſinuating itſelf between the particles of bodies, ſeparates them from each other ; and, even allowing the exiſtence of this fluid to be hypothetical, we ſhall ſee in the ſequel, that it explains the phenomena of nature in a very ſatisfac‍tory manner.

This ſubſtance, whatever it is, being the cauſe of heat, or, in other words, the ſenſation which we call warmth being cauſed by the accumulation of this ſubſtance, we cannot, in ſtric‍t language, diſtinguiſh it by the term heat; becauſe the ſame name would then very improperly expreſs both cauſe and effec‍t. For this reaſon, in the memoir which I publicſhed in 1777 *, I gave it the names of igneous fluid and matter of heat : And, ſince that time, in the work † publicſhed by Mr de Morveau, Mr Berthollet, Mr de Fourcroy, and myſelf, upon the reformation of chemical nomenclature, we thought it neceſſary to baniſh all periphraſtic expreſſions, which both lengthen phyſical language, and render it more tedious and leſs diſtinc‍t, and which even frequently does not convey ſufficiently juſt ideas of the ſubjec‍t intended. Wherefore, we have diſtinguiſhed the cauſe of heat, or that exquiſitely elaſtic fluid which produces it, by the term of caloric. Beſides, that this expreſſion fulfils our objec‍t in the ſyſtem which we have adopted, it poſſeſſes this farther advantage, that it accords with every ſpecies of opinion, ſince, ſtric‍tly ſpeaking, we are not obliged to ſuppoſe this to be a real ſubſtance ; it being ſuſſicient, as will more clearly appear in the ſequel of this work, that it be conſidered as the repulſive cauſe, whatever that may be, which ſeparates the particles of matter from each other; ſo that we are ſtill at liberty to inveſtigate its effec‍ts in an abſtrac‍t and mathematical manner.

In the preſent ſtate of our knowledge, we are unable to determine whether light be a modification of caloric, or if caloric be, on the contrary, a modification of light. This, however, is indiſputable, that, in a ſyſtem where only decided fac‍ts are admiſſible, and where we avoid, as far as poſſible, to ſuppoſe any thing to be that is not really known to exiſt, we ought proviſionally to diſtinguiſh, by diſtinc‍t terms, ſuch things as are known to produce different effec‍ts. We therefore diſtinguiſh light from caloric ; though we do not therefore deny that theſe have certain qualities in common, and that, in certain circumſtances, they combine with other bodies almoſt in the ſame manner, and produce, in part, the ſame effec‍ts.

What I have already ſaid may ſuſſice to determine the idea affixed to the word caloric ; but there remains a more difficult attempt, which is, to give a juſt conception of the manner in which caloric ac‍ts upon other bodies. Since this ſubtile matter penetrates through the pores of all known ſubſtances; ſince there are no veſſels through which it cannot eſcape, and, conſequently, as there are none which are capable of retaining it, we can only come at the knowledge of its properties by effec‍ts which are fleeting, and difficultly aſcertainable. It is in theſe things which we neither ſee nor feel, that it is eſpecially neceſſary to guard againſt that extravagancy of our imagination, which forever inclines to ſtep beyond the bounds of truth, and is very difficultly reſtrained within the narrow line of fac‍ts.

We have already ſeen, that the ſame body becomes ſolid, or fluid, or aëriform, according to the quantity of caloric by which it is penetrated ; or, to ſpeak more ſtric‍tly, according as the repulſive force exerted by the caloric is equal to, ſtronger, or weaker, than the attrac‍tion of the particles of the body it ac‍ts upon.

But, if theſe two powers only exiſted, bodies would become liquid at an indiviſible degree of the thermometer, and would almoſt inſtantaneouſly paſs from the ſolid ſtate of aggregation to that of aëriform elaſticity. Thus water, for inſtance, at the very moment when it ceaſes to be ice, would begin to boil, and would be transformed into an aëriform fluid, having its particles ſcattered indefinitely through the ſurrounding ſpace. That this does not happen, muſt depend upon the ac‍tion of ſome third power. The preſſure of the atmoſphere prevents this ſeparation, and cauſes the water to remain in the liquid ſtate till it be raiſed to 80° of temperature (212°) above zero of the French thermometer, the quantity of caloric which it receives in the loweſt temperature being inſufficient to overcome the preſſure of the atmoſphere.

Whence it appears that, without this atmoſpheric preſſure, we ſhould not have any permanent liquid, and ſhould only be able to ſee bodies in that ſtate of exiſtence in the very inſtant of melting, as the ſmalleſt additional caloric would inſtantly ſeparate their particles, and diſſipate them through the ſurrounding medium. Beſides, without this atmoſpheric preſſure, we ſhould not even have any aëriform fluids, ſtrc‍tly ſpeaking, becauſe the moment the force of attrac‍tion is overcome by the repulſive power of the caloric, the particles would ſeparate themſelves indefinitely, having nothing to give limits to their expanſion, unleſs their own gravity might collec‍t them together, ſo as to form an atmoſphere.

Simple reflec‍tion upon the moſt common experiments is ſuſſicient to evince the truth of theſe poſitions. They are more particularly proved by the following experiment, which I publicſhed in the Memoirs of the French Academy for 1777, P. 426.

Having filled with ſulphuric ether * a ſmall narrow glaſs veſſel, A, (Plate VII. Fig. 17.), ſtanding upon its ſtalk P, the veſſel, which is from twelve to fifteen lines diameter, is to be covered by a wet bladder, tied round its neck with ſeveral turns of ſtrong thread ; for greater ſecurity, fix a ſecond bladder over the firſt, Tht veſſel ſhould be filled in ſuch a manner with the ether, as not to leave the ſmalleſt portion of air between the liquor and the bladder. It is now to be placed under the recipient BCD of an air-pump, of which the upper part B ought to be fitted with a leathern lid, through which paſſes a wire EF, having its point F very ſharp; and in the ſame receiver there ought to be placed the barometer GH. The whole being thus diſpoſed, let the recipient be exhauſted,,and then, by puſhing down the wire EF, we make a hole in the bladder. Immediately the ether begins to boil with great violence, and is changed into an elaſtic aëriform fluid, which fills the receiver. If the quantity of ether be ſuſſicient to leave a few drops in the phial after the evaporation is finiſhed, the elaſtic fluid produced will fuſtain the mercury in the barometer attached to the air-pump, at eight or ten inches in winter, and from twenty to twenty-five in ſummer *. To render this experiment more complete, we may introduce a ſmall thermometer into the phial A, containing the ether, which will deſcend conſiderably during the evaporation.

The only effec‍t produced in this experiment is, the taking away the weight of the atmoſphere, which, in its ordinary ſtate, preſſes on the ſurface of the ether; and the effec‍ts reſulting from this removal evidently prove, that, in the ordinary temperature of the earth, ether would always exiſt in an aëriform ſtate, but for the preſſure of the atmoſphere, and that the paſſing of the ether from the liquid to the aëriform ſtate is accompanied by a conſiderable leſſening of heat; becauſe, during the evaporation, a part of the caloric, which was before in a free ſtate, or at leaſt in equilibrio in the ſurrounding bodies, combines with the ether, and cauſes it to aſſume the aëriform ſtate.

The ſame experiment ſucceeds with all evaporable fluids, ſuch as alkohol, water, and even mercury ; with this difference, that the atmoſphere formed in the receiver by alkohol only ſupports the attached barometer about one inch in winter, and about four or five inches in ſummer; that formed by water, in the ſame ſituation, raiſes the mercury only a few lines, and that by quickſilver but a few frac‍tions of a line. There is therefore leſs fluid evaporated from alkohol than from ether, leſs from water than from alkohol, and ſtill leſs from mercury than from either; conſequently there is leſs caloric employed, and leſs cold produced, which quadrates exac‍tly with the reſults of theſe experiments.

It would have been more ſatisfac‍tory if the Author had ſpecified the degrees of the thermometer at which theſe heights of the mercury in the barometer are produced.

Another ſpecies of experiment proves very evidently that the aëriform ſtate is a modification of bodies dependent on the degree of temperature, and on the preſſure which theſe bodies undergo. In a Memoir read by Mr de la Place and me to the Academy in 1777, which has not been printed, we have ſhown, that, when ether is ſubjec‍ted to a preſſure equal to twenty-eight inches of the barometer, or about the medium preſſure of the atmoſphere, it boils at the temperature of about 32° (104), or 33° (106.25°), of the thermometer. Mr de Luc, who has made ſimilar experiments with ſpirit of wine, finds it boils at 67° (182.75°). And all the world knows that water boils at 80° (212°). Now, boiling being only the evaporation of a liquid, or the moment of its paſſing from the fluid to the aëriform ſtate, it is evident that, if we keep ether continually at the temperature of 33° (106.25°), and under the common preſſure of the atmoſphere, we ſhall have it always in an elaſtic aëriform ſtate; and that the ſame thing will happen with alkohol when above 67° (182.75°), and with water when above 80° (212°); all which are perfec‍tly conformable to the following experiment *.

I filled a large veſſel ABCD (Plate VII. Fig. 16.) with water, at 35° (110.75°), or 36° (113°) ; I ſuppoſe the veſſel tranſparent, that we may ſee what takes place in the experiment; and we can eaſily hold the hands in water at that temperature without inconvenience. Into it I plunged ſome narrow necked bottles F, G, which were filled with the water, after which they were turned up, ſo as to reſt on their mouths on the bottom of the veſſel. Having next put ſome ether into a very ſmall matraſs, with its neck a b c, twice bent as in the Plate, I plunged this matraſs into the water, ſo as to have its neck inſerted into the mouth of one of the bottles F. Immediately upon feeling the effec‍ts of the heat communicated to it by the water in the veſſel ABCD it began to boil; and the caloric entering into combination with it, changed it into elaſtic aëriform fluid, with which I filled ſeveral bottles ſucceſſively, F, G, &c.

This is not the place to enter upon the examination of the nature and properties of this aëriform fluid, which is extremely inflammable; but, confining myſelf to the objec‍t at preſent in view, without anticipating circumſtances, which I am not to ſuppoſe the reader to know, I ſhall only obſerve, that the ether, from this experiment, is almoſt only capable of exiſting in the aëriform ſtate in our world ; for, if the weight of our atmoſphere was only equal to between 20 and 24 inches of the barometer, inſtead of 28 inches, we ſhould never be able to obtain ether in the liquid ſtate, at leaſt in ſummer ; and the formation of ether would conſequently be impoſſible upon mountains of a moderate degree of elevation, as it would be converted into gas immediately upon being produced, unleſs we employed recipients of extraordinary ſtrength, together with refrigeration and compreſſion. And, laſtly, the temperature of the blood being nearly that at whi...

Table of contents

• Cover
• Title Page
• Copyright
• Elements of Chemistry
• Contents
• Part I.
• Part II.
• Part III.
• Appendix.