PIERRE AUGlJSTE ADET* Priestley's persistent espowal of the phlogiston theory was continued after he came to America. In 1796 he published the first of a series of four @mphlets. The fallacy of his arguments was promptly exposed by the French chemist Adet who at that time was the French Ambassador to the United States. The young American republic was promptly recognized by the young French republic. Representatives were sent by one to the other. The fifth of the French representatives was Pierre Auguste Adet. He came to Philadelphia in June, 1795. Like his immediate predecessor, Genet, he was an ardent Frenchman, still imbued with revolutionary ideas of action or a t least revolutionary methods of diplomacy. Unlike Genet he was not fantastic in his views; indeed he might be classified as a member of the intermediate class, bidding the excesses of the French Revolution adieu with one hand and welcoming the orderly procedure of the new republic with PIE= AUGUSTEADET the other. His interFrench ambassador to the United States, 1795-6. course and his controversies, private as well as public, even his dress, show this dual relation. Adet differed from all his predecessors in one significant respect. He was a chemist. And it is with Adet the chemist, not the diplomat, we are a t present concerned. Definite references t o him and his work are few. Undoubtedly, he shared the responsibility of the younger contingency of chemists during the early days of the French Revolution because by 1787 he had assimilated Lavoisier's fundamental work on the overthrow of the phlogiston theory and was definitely aligned with Lavoisier, Fouraoy, de
* Read at the seventy-second meeting of the American Chemical Society. September 6 1 1 , 1926. Philadelphia. Penna. 43
44
JOURNAL OF CHEMICAL EDUCATION
J a ~ u a n u 1931 ,
Morveau, and Berthollet, and more specifically with Hassenfratz. These two chemists, Hassenfratz and Adet, must have become early converts to the views of Lavoisier, because they had already worked out a fairly complete system of chemical symbols for representing the new chemistryla chimie frangaise. Their system was described in two papers published early in 1787 (Mdmoires sur de nouveuux Carac?hes & employer en Chimie), and was regarded by Lavoisier and his associates as so essential to the new chemistry that it was appended to that memorable book, "M&t!zude de Nomenclature Chimique proposde @r Mm. de Morueau, Lavoisier, Berthollet, et de Fourcroy," which appeared late in 1787. The symbols devised by Hassenfratz and Adet were geometrical, and were constructed of straight lines, semicircles, circles, and in some cases arcs. Each simple substance was assigned a symbol, making fifty-four in all. Straight Smes and semicircles were used for non-metallic simple substances and circles enclosing the initial letters of their names were for sulfur, ) for hydrogen, used for metals. Thus, - stood for oxygen,
-
-
for phosphorus,
@ for nickel and @ for lead. Symbols for com-
pounds were intended to indicate the nature, number, and relative quantities of their simple components. Thus, @ represented lead phosphide and 'j hydrogen sulfide. Other geometrical combiiations represented an acid radical, an alkali, a gas, a liquid, an excess of a simple substance in a compound. Relative quantities in a compound were indicated by different positions of one of the elements. Lavoisier, Bertbollet, and de Fourcroy in their report to the French Academy of Sciences on this system of Hassenfratz andAdet, praised the system because it brought facts before the eye, gave correct ideas of the composition of compounds, and established a rule for writing the symbols of new compounds. The geometrical symbols of Hassenfratz and Adet, like those of the alchemists who preceded, and of John Dalton who followed, were completely superseded by the symbols introduced by Berzelius about 1814. Nevertheless, Adet and his associate deserve credit for devising a system of symbols which supplemented the contemporary system of nomenclature. In his writings Adet used Lavoisier's system of naming elements and compounds, and as a chemist he was a staunch advocate of the new chemistry, thereby rendering great service to chemistry in America and elsewhere. The literature contains only a few references to Adet's experimental work, the most important being a paper on the liquor of Lihavius (1). As stated above, Adet came to Philadelphia in June, 1795, about a year after Priestley amved in America. In 1796 Priestley published the first of a series of four pamphlets on phlogiston and the decomposition of water.
VOL.8. NO. 1
PIERRE AUGUSTE ADET
45
These pamphlets are accurately described and fully discussed in a paper by Dr. Tenney L. Davis (2) and need not be considered here. We need only note that Priestley adhered firmly to the doctrine of phlogiston and asserted that his experiments showed that water is a simple substance, not a compound of hydrogen and oxygen. A controversy was immediately precipitated, which lasted about seven years. Two opponents of Priestley entered the field a t once: John Maclean (3), professor of chemistry at Princeton University, and Pierre Auguste Adet. The 1796 pamphlet was addressed: To Messrs. Berthollet, de la Place, Monge. Momeau, Foumoy, and Hassenfratz, the surviving answerers of Mr. Kirwan, .and I request the favour of an answer to my objections.
...
Answers came quickly. The first was from Adet, whose name strangely enough had not been included among those from whom Priestley requested ' the favour of an answer." Adet must have obtained very early a copy of the pamphlet because he translated it into French and published the translation with his response in 1797 as a pamphlet of 96 pages, the title page of which is shown on page 46. Priestley's k t pamphlet appeared soon after Maclean began his work a t Princeton. The pamphlet was reviewed by Maclean, in "Two Lectures on Combustion Supplementary to a Course of Lectures." This review by Maclean was published, and with the following advertisement prefixed: t
Owing to other engagements a part only of the first of these lectures was read to the students. They are now printed to save the young gentlemen the trouble of transcribing them. P.S. It was not till after they were s&t to the press that I was informed Mr. Adet had published an answer to Dr. Priestley's pamphlet.
Adet's pamphlet was published about a week before Maclean's. Samuel L. Mitchell (4), professor of chemistry in King's College (later Columbia University) and editor of the Medical Refiository, entered the controversy and opened the pages of his journal to the participants. James Woodhouse also joined the controversy and argued for a time on both sides of the question, though he finally took his stand against phlogiston on the iirm ground of experiment. Adet's response was not only prompt, hut sharp, logical, and adequate. It was confined chiefly to the second part of the question; uiz., the decomposition of water, though of course the two parts were interwoven. This form of attack was wise because it could be based on f a d s recently obtained by simple experiments. After expressing his amazement that any one acquainted with the experi-
VOI. 8, No. 1
47
PIERRE AUGUSTE ADET
mental results should still persist in denying that water could he decomposed, Adet says he felt driven to state once again: (1) That in causing water to pass through a red-hot gun barrel, the iron hecomes oaydated by the oxygen of the water; (2) notwithstanding the di5erence which exists between the black oxyd of iron, produced by the decompositionof water, and thecommon for these reasons: that, red oxvd of the same metal.. they . are still both of them oavds, . like other oxyds, they both dissolve in acids without disengaging anything, and metallic bodies are incapable of combining with acids unless they are previously united to oxygen; (3) although there is same difference between this oxyd and the common red oxyd, i t does not follow that they are not both ouyds: . . the difference between the two being only owing to the different circumstances under which they have combined with oxygen. ~
In general Adet asserted that Priestley's objections to the compound nature of water could he explained without the phlogiston idea. The participation of Adet in this dis&sion was regarded by most American and European chemists as a determining factor, and his arguments alone, so they thought, would have convinced the most skeptical phlogistonist. But Priestley was tenacious and obdurate. I n the fourth and last pamphlet (18034) he reprints his letter to the French chemists and says also (among other things). On the opening of this contruversy I told Mr. Adet that I should have greater pride in acknowledging myself convinced, if I saw reason to be, than in victory, and should surrender my arms with pleasure. I was sincere in that declaration; and certainly the conquest of a man's prejudice is more honourable to h i than the discovery, or the most successful defence, of truth. This, however, I must, for the present, a t least, decline, and leave it to you; contenting myself with the inferior praise of confirming the hypothesis for which I have contended. If, from the politeness habitual to Frenchmen, you should decline this honour, thinking my claim better founded to i t than yours, I may hereafter be induced to receive it; hut for the present, yielding to you a palm more glorious than that of any victory, and trusting that your political revolution may be more stable than this chemical one. I am, with greatest respect, Gentlemen. Your fellow citizen, Joseph Priestley. Northumberland in America, Oct. 22, 1803.
Adet's response, as given ahove, was his only written contribution t o the phlogiston-water controversy. For on Nov. 25, 1796, Adet issued a note saying, Citizen P. A. Adet informs his fellow citizens that by order of the Executive Directory, he has today notified the Secretary of State the suspension of the functions of the Minister Plenipotentiary of the French Republic to the United States of America.
The activities of Adet the politician are so fully recorded in official papers and other documents of the period that they need not be considered in a paper dealing with Adet the chemist. After leaving the United States he held other diplomatic and semi-official posts under the French government. However, he retained his interest in chemistry and in 1804 issued a book entitled "Le~onsEldmataire de Chimie." Adet died in 1832.
45
JOURNAL OF CHEMICAL EDUCATION
JANUARY,
1931
Literature Cited "SUI le muriate d'6tain fumant ou Liqueur de Libavius," Ann. chim., ( I ) LIBAVIUS, 1, 5 (1794). (2) DAVIS."Priestley's Last Defense of Phlogiston," J. CHEM.EDUC., 4, 1 7 M (Feb., 1927). "Doctor Maclean and the Doctrine of Phlogiston," ibid., 2, 7G-7 (3) FOSTER, (Sept., 1925). ( 4 ) HALL,"A Chemist of a Century Ago," ibid., 5, 250, 253-7 (Mar., 1928).
