(b. Cortaillod, Neuchiâtel, Switzerland, 9 June 1805; d. Paris, France, 12 or 18 September 1868), chemistry.
After working in several pharmacies in Neuchâtel, Persoz went to Paris, to study under Thenard at the Collège de France. From 1826 to 1832 he was préparateur to Thenard, and in 1833 he earned his docteurès sciences physiques from the Paris Faculty of Sciences. Persoz then spent seventeen years (1833–1850) in Strasbourg in scientific, teaching, and administrative posts, including those of professor of chemistry at the Faculty of Sciences, assayer of the Mint, and professor of chemistry and director of the Strasbourg School of Pharmacy. Returning to Paris in 1850, Persoz became a suppléant to Dumas, who was then teaching chemistry at the Sorbonne; he was appointed maître de conférences at the École Normale Supérieure at about the same time. In 1852 he received a professorship at the Conservatoire des Arts et Métiers, where he lectured on dyeing and printing of textiles.
Among Persoz’s most important accomplishments were two collaborative works published in 1833. The first, written with Anselme Payen, reported the isolation of diastase from malt extract; this research revealed that diastase converts starch into sugar. The second work, written with Biot, showed that the partial hydrolysis of starch with mineral acids yields a substance (dextrin) that proved dextrorotatory on the plane of polarized light, and that a similar effect on polarized light can be obtained by boiling cane sugar with dilute acid.
Persoz later published an influential book on the chemistry of molecular combinations, Introduction àl’ étude de la chimie moléculaire (Paris-Strasbourg, 1839), and a four-volume treatise with an atlas on textile printing, Traité théorique et pratique de l’impression des tissus (Paris, 1846). Noteworthy, too, among his numerous investigations were his discovery of the production of methane by heating an acetate with caustic alkali (1839), his method for combining sulfur dioxide and phosphorus pentachloride to obtain thionyl chloride (1849), and his work on tungsten compounds (1863). Many of his publications dealt with analytical chemistry and chemical technology.
I. Original Works. In addition to his treatises on the chemistry of molecular combinations (1839) and on the printing of textiles (1846) already mentioned, Persoz published many papers in the Comptes rendus hebdomadaires des séances de 1’Académie des Sciences, and in leading chemical journals of the day. For listings of Persoz’s articles written alone or with others, see Poggendorff, II, 408–410, and III, 1024; and the Royal Society Catalogue of Scientific Papers, IV, 838–840, and VIII, 596.
II. Secondary Literature. See Fritz Ferchl, Chemisch Pharmazeutisches Bio- and Bibliographikon (Mittenwald, 1937), 404–405; Gabriel Humbert, Contribution à l’histoire de la pharmacie strasbourgeoise (Mulhouse, 1938), 217–219; E. V. McCollum, A History of Nutrition (Boston, 1957), 13–14, and passim; J. R. Partington, A History of Chemistry, IV (London-New York, 1964), 429 and passim; and René Sartory,“Jean-François Persoz,” in Figures pharmaceutiques françaises (Paris, 1953), 95℃100.