Favre, Pierre Antoine

(b. Lyons, France, 20 February 1813; d. Marseilles, France, 17 February 1880)

chemistry.

Favre received a medical degree from the Faculty of Medicine in Paris in 1835. Inspired by Jean Dumas’s lectures in chemistry at the School of Medicine in 1840, he turned to chemistry. He was admitted to Eugene Peligot’s private laboratory and helped in the latter’s classic work on uranium compounds; he became Peligot’s préparateur at the Conservatory of Arts and Manufactures. He was named fellow of the Faculty of Medicine of Paris in 1843 and worked in G. Andral’s laboratory on physiological problems. In 1851 he became head of the analytical chemistry laboratory of the Central School of Arts and Manufactures, while continuing as a fellow of the Faculty of Medicine. In 1853 he received the degree of Doctor of Physical Science. He was named professor of chemistry of the Faculty of Science of Besancon in 1854 and was called to the newly created Faculty of Science at Marseilles in 1856.

Twice leureate of the French Academy of Sciences, Favre was elected a correspondent of the chemistry section in 1864 and a correspondent of the physics section in 1868. Favre became dean of the Faculty of Science in Marseilles in 1872, retiring in 1878 because of ill health.

Favre’s earliest independent researches were determinations of the equivalent weight of zinc and studies of cupric carbonate and the ammonium carbonates of zinc and magnesium. He wrote several papers on such physiologically important compounds as lactic acid, mannitol, and the constituents of human perspiration.

His interests turned to thermochemistry about 1848—indeed, Favre is perhaps best-known for using the term “calorie” (1853) to denote the unit of heat. Between 1845 and 1853, he and Johann T. Silbermann, a French physicist, collaborated in a series of important thermochemical researches. They demonstrated the falsity of Dulong’s rule, which states that the heat of combustion of a compound composed of carbon and hydrogen is the sum of the heats of combustion of the elements it contains. Particularly valuable was their study of the heats of combustion and formation of a large number of substances using a newly devised “mercury calorimeter.” The instrument was somewhat inaccurate, and their results were superseded after some years but were nevertheless widely used. They also showed that the heat of combustion of carbon in oxygen is less than that of carbon in nitrous oxide, evidence that helped to strengthen the case for the diatomicity of the oxygen molecule. The collaboration between Favre and Silbermann was influential in replacing the vague notion of chemical affinity with more precise thermodynamic expressions.

In 1857 Favre elegantly substantiated Joule’s ideas about the conservation of energy by means of a voltaic battery operating an electric motor which raised a weight. He showed that the total heat evolved in the battery and the circuit, when added to the equivalent in heat required to raise the weight, was equal to that evolved by the battery alone when it was short-circuited.

Shortly before retirement Favre and the mathematician Claude Valson determined both the heats and the volume changes of solution of many salts. This study was cited by Arrhenius in defense of the theory of electrolytic dissociation. Favre was often called upon by the state and by commercial interests; he served as a consultant in the preparation of canned foods, salt, and petroleum distillates for house and street illumination.

Favre was a careful and skillful experimenter. Highly regarded by his contemporaries for his diligence and chemical ability, his mission was to gather data, not to devise the bold new hypotheses which alter the scientific paradigm.

BIBLIOGRAPHY

I. Original Works. Favre’s works include more than seventy papers (alone or with collaborators), which are listed by Poggendorff and in the first series of the Catalogue of Scientific Papers of the Royal Society of London.

II. Secondary Literature. J. S. Partington gives a brief analysis of Favre’s work in A History of Chemistry, IV (London, 1964), 691 and passim. A short biography by F. LeBlanc, “Notice nécrologique sur P. A. Favre...,” is in Bulletin de la Société chimique de Paris, 33 (1880), 390–400; see also Comptes rendus hebdomadaires des séances de l’Académie des sciences, 90 (1880), 329. There is no detailed study of his life and achievement.

Louis Kuslan