PREVOST, PIERRE

(b. Geneva, Switzerland, 3 March 1751; d. Geneva, 8 April 1839)

physics, philosophy, literature.

Prevost’s principal contribution to physics was his theory of exchanges, enunciated in 1791, in which he stated that all bodies regardless of temperature are constantly radiating heat and that an equilibrium of heat between two bodies consisted in an equality of exchange. W. C. Wells’s theory of the formation of dew was a consequence of Prevost’s hypothesis, and Fourier took Prevost’s work as the basis for his mathematical analysis of heat radiation.

Prevost’s father, a Calvinist minister and principal of the college of Geneva, made every effort to assure the excellence of his children’s education. Consequently, Prevost studied not only the classical languages and literatures but also the sciences under H. B. de Saussure, Lesage, and Mallet. In accordance with his father’s wishes he pursued theology for several years but then turned to law and received his doctorate in 1773.

From 1773 to 1780 Prevost worked as a teacher and tutor in Holland, in Lyons, and finally in Paris. Simultaneously, he was engaged in a translation of the works of Euripides; in 1778 he published Orestes, which gained him fame among classical scholars. As a result, he was invited to Berlin in 1780 by Frederick the Great as a member of the Academy of Sciences and Belles-Lettres. While in Berlin, Prevost contributed several memoirs on moral philosophy and poetry, and stimulated by Lagrange, published articles on scientific subjects. Upon the death of his father in 1784, he returned to Geneva and filled the chair of literature there for a year before going to Paris to work on an edition of Greek drama. Late in 1786 he returned to Geneva and became active in politics, serving as a member of the Council of Two Hundred, as attorney general, and as a member of the national assembly created to change the constitution of Geneva.

In 1788 Prevost published De l’origine des forces magnétiques, which made him known among physicists, and thereafter he became principally interested in heat phenomena owing to the publication in 1790 of Essai sur le feu, the work of a fellow Genevan. Marc Auguste Pictet. Pictet, following Deluc, believed that heat consisted in a continuous material fluid and that the radiation of heat between two objects at unequal temperatures was accomplished by the progressive expansions and contractions of this fluid, drawing an analogy between this process and the transmission of sound. Rejecting this view in “Sur l’équilibre du feu” (1791), Prevost conceived of heat as a “discrete fluid” or medium composed of particles the intervals of which are very great in comparison to their dimensions; during the process of radiation these particles, in the form of rays, stream continuously between the two radiating bodies. When the equilibrium of heat is upset, it is gradually reestablished by the unequal exchange of particles. In later writings Prevost clarified his ideas while retaining his conviction in the materiality of heat.

In 1793 Prevost was named to the chair of philosophy and general physics at Geneva, and he retained this post until his retirement in 1823. He wrote extensively on political economy, psychology, public education, probability theory, electricity, and meteorology. He translated Adam Smith’s Wealth of Nations, Malthas’s Essay on Population, the moral philosophy of Dugald Stewart, and Hugh Blair’s works on rhetoric. In addition, Prevost maintained an active correspondence with scientists, philosophers, and classical scholars throughout Europe. He was named a corresponding member of the Royal Society of Edinburgh in 1796, of the Royal Society of London in 1801, and of the Institute of France in 1801.

Early in the French Revolution Prevost argued for the continued independence of Geneva and pleaded for moderation in the social and political reform of the city-state, which led to his detention for three weeks in 1794 by the revolutionary party. In 1798 he was named to the commission that regulated the union of Geneva with France; and in 1814, when Geneva was restored to the status of a republic, he was elected a member of the representative council.

Prevost remained mentally active until his death. In his last years he turned his attention to the study of aging in human beings, writing in detail about the progressive physical infirmities that he observed in himself.

BIBLIOGRAPHY

I. Original Works. Prevost’s principal works are Euripide, (Paris, 1782); De l’economie des anciens gouvernemens comparée à celle des gouvernemens modernes (Berlin, 1783); De l’origine des forces magnétiques (Geneva, 1788); “Sur l’équilibre du feu,” in Journal de physique, 38 (1791), 314-332; Recherches physico-mécaniques sur la chaleur (Geneva, 1792); Genève, égalité, indépendance, libetié (Geneva, 1793); Essais philosophiques par feu Adam Smith (Geneva, 1797); Des signes envisagés relativement à leur influence sur la formation des idées (Paris, 1798); Essais de philosophic, 2 vols. (Geneva, 1804); Dugald Stewart: Éléments de la philosophie de resprit humain, 2 vols. (Geneva, 1808); Malthas: L’essai sur le principe de population (Geneva, 1809); Du calorique rayonnant (Paris, 1809); Deux traités de physique mécanique (Geneva, 1818); and Exposition élémentaire des principes qui servent de base à la théories de la chaleur rayonnante (Geneva, 1832). An extensive collection of Prevost’s MSS is in the archives of the Bibliotheque Publique et Universitaire de Geneve.

II. Secondary Literature. On Prevost’s life and work, see C. Bartholmerz, “Pierre Prevost,” in Dictionnaire des sciences philosophiques (Paris. 1851), 208-211; A. P. de Candolle, “Notice sur Pierre Prevost,” in Archives des sciences physiques et naturelles, 19 (1839), 1- 10; and A. Cherbuliez, Discours sur la vie et les travaux de feu Pierre Prevost (Geneva, 1839).

John G. Burke