Duclaux, Pierre Émile

Born June 24, 1840, in Aurillac; died May 3, 1904, in Paris. French microbiologist and chemist. Member of the Paris Academy of Sciences (1888).

Upon graduation in 1862 from the Higher Normal School in Paris, Duclaux worked in the laboratory of L. Pasteur. From 1895 he was director of the Pasteur Institute. He investigated the chemical composition of milk, lactic fermentation, the action of rennin, and the composition and formation of various cheeses. He proposed a method of identifying volatile acids by means of fractional distillation; he studied the phenomenon of osmosis and the movement of liquids in capillary tubes. Duclaux summarized his works on microbes and the role of microbes in the development of diseases in the four-volume work Microbiology (1898-1901).