(b. Geneva, Switzerland, 23 July 1752; d. Geneva, 19 April 1825)
The son of Charles Pictet and Marie Dunant, Pictet came of an old and respected Genevan family. After a private education he studied at the Law Faculty of the Academy of Geneva, and it was only after qualifying as a lawyer in 1774 that he returned his attention seriously to science. His first mentor was the astronomer J. A. Mallet-Favre; but the greatest influence on him during his early years was that of H. B. de Saussure, who fostered Pictet’s interest in physics and meteorology and secured his appointment to the chair of philosophy at the Academy of Geneva when age and ill health brought about his own retirement in 1786.
Pictet was always prominent in public life. At the time of Geneva’s annexation to France in 1798, he did much to protect the interests of his city and of the Protestant religion, to which he ardently subscribed. Respected by Napoleon and a frequent visitor to Paris during the Consulate and Empire, he served as a member of the Tribunate from 1802 until 1807 and as one of the inspectors of the Imperial University from 1808 to 1815. He was prominent also in the scientific cicles of Paris at this time; Berthollet and other French scientists were among his closest friends, and he often attended meetings of the first class of the Institut de France, of which he became a nonresident associate in 1802 and a corresponding member in 1803. His many other honors included membership of the Legion of Honor (1804) and fellowships of the Royal Society of London and of Edinburgh (1791 and 1796, respectively). By his marriage to Susanne Francoise Turrettini, which lasted from 1776 until her death in 1811, he had three daughters.
Pictet’s most important research, a series of experiments on heat and hygrometry, was described in his Essai sur le feu (1790). Although widely read and even translated into English and German, the Essai broke little new ground. For example, his demonstration that radiant heal is reflected in the same way as light merely confirmed a conclusion already reached by J. H. Lambert and Saussure. And his experiments on the refraction and velocity of radiant heat, which could have led to results of great interest, were inconclusive, Although Pictet’s research was mainly experimental, he was not uninterested in theory. In the Essai, for instance, he discussed the competing vies of the nature of heat at some length and, although unwilling to commit himself, declared a slight preference for the material theory in the form given by Lavoisier. Hence he chose to consider heat as the fluid caloric rather than as a vibration either of the ordinary particles of matter or, in the maner of several Swiss scientists, of an all-pervading subtle fluid. He also opposed many of his compatriots by taking up Lavoisier’s cause in the struggle for the acceptance of the new chemistry, and it was in a series of lectures given by Pictet in 1790 that Lavoisier’s views were first given public support in Geneva.
Although Pictet earned a considerable reputation by his own research, which embraced geology, geodesy, astronomy, and meteorology as well as physics, he was even better known for his help and encouragement to others. In Geneva he worked tirelessly as a leading member of the Societe des Arts, the Societe de Physique et d’Histoire Naturelle. and the Societe Helvetique des Sciences Naturelles; and he made what were probably his most important contributions to science as the joint founder and editor of two scientific journals: the Journal de Geneve (published by the Societe des Arts from 1787 to 1791) and the Bibliotheque britmmique, founded in 1796 in collabora collaboration with his younger brother Charles and his friend F. G. Maurice . Established originally to inform Continental readers of British publications and research, the Bibliotheque britannique was especially important in the maintenance of communications between Britain and the Continent during the Napoleonic Wars . After 1815, when it abandoned its special concern for British science and was renamed the Bibliotheque universelle, the journal continued to serve as a source of information that took little account of national barriers, although after 1815 Swiss contributions increased in number and importance .
Through his extensive international correspondence and his travels—mainly in France, Italy, and Britain—Pictet won many friends. As a zealous worker for science, a discerning editor, a patriot who showed no trace of chauvinism, and a man of great gentleness and modesty, he fully deserved the high esteem in which he was held throughout his life.
I . ORIGINAL WORKS . Pictet’s Essai sur le feu (Geneva, 1790), trans . into English by W. B[elcombe] as An Essay on Fire (London, 1791), was intended to be the first volume in a work entitled Essais de physique, but no further volumes were published . His Voyage de trois mois en Angleterre, en Ecosse, et en Irlande pendant l’ete de l’an IX (1801 v. st .) (Geneva, an XI ), first published as a series of letters to the Bibliotheque britannique, is a very interesting account . His numerous contributions to the Bibliotheque britannique and the Bibliotheque universelle are listed in the Royal Society Catalogue of Scientific Papers, IV, 902-903 ; but his articles in the Memoires de la Societe des arts and the Menoires de la Societe de physique et d’histoire naturelle do Geneve are not mentioned . Some of Pictet’s correspondence with other Genevans is preserved at the Bibliotheque Publique et niversitaire of Geneva, but most of his personal papers and other correspondence are in the possession of the Rilliet family of Geneva. A copy, by Edmond Pictet, of a diary kept by Pictet while in Paris between 1802 and 1804 has been published as “Journal d’un genevois a Paris,” in Memoircs et documents publics par la Societe c/’histoire et d’archeologie de Geneve, 2nd ser ., 5 (1893-1901), 98-133 .
II.secondary literature. The standard biographical source is the obituary by J. P. Vaucher, in Biblotheque universelle, see. “Sciences el Arts,” 29 (1825), 65-88. Other useful sketches are R. Wolf, Biographien zur Kulturgeschiclle dev Schweiz, 111 (Zurich, I860), 373- 394; Michaud, ed., Biographie universelle, new ed., XXXIII, 208-210; and A. de Montet, Dictionaire biographiqtic des genevois et des vattdois, II (Lausane, 1878), 296-298. A MS of Edmond Pictet’s “Dates des principales fonctions publiques, distinctions scienlifiqucs el autres, dans la vie de Marc-Augusle Pictet,” in the Bibliotheque Publique et Universitaire in Geneva, contains useful information not available elsewhere. Accounts of Pictet’s conections with Mine de Stael and of his part in the introduction of Lavoisier’s ideas in Geneva appear in P. Kohler, Madame de Stael et la Suisse (Lausane- Paris, 1916), 408-412; and J. Deshusses, “Le physicien Marc-Ausic fictet et fadoplion de la doctrine chimique dc Lavoisier par les savants genevois,” in Bulletin de l’stititu national geneois, 61 (1961), 100-112. His work for the Bibliotheque brilanique is discussed in D. M. Bickcrton, “A Scientific and Literary Periodical, the Bibliotheque britunique (1796-1815): Its Foundation and Early Development,” in Revue de l’literature comparée, 4 (1972), 527-547.