BERTHELOT, (PIERRE-EUGNE-) MARCELLIN

born Oct. 27, 1827, Paris died March 18, 1907, Paris French organic and physical chemist, science historian, and government official whose creative thought and work significantly influenced the development of chemistry in the latter part of the 19th century. Berthelot began his career as a staff assistant to Antoine-Jrme Balard at the Collge de France, Paris (1851). His doctoral thesis, based on a continuation and amplification of Michel-Eugne Chevreul's work with glycerol, established his reputation. Appointed professor of organic chemistry at the cole Suprieure de Pharmacie, Paris (1859), he accepted a chair in organic chemistry created for him at the Collge de France (1865). Inspector of higher education (1876), he continued an active interest in educational problems. He was elected a life senator in 1881. He was also minister of public instruction (188687) and of foreign affairs (189596). Berthelot did important research in alcohols and carboxylic acids, in the synthesis of hydrocarbons (including acetylene), and in reaction velocities. As a result of his work on explosives, he discovered the detonation wave. He discredited the generally held contention that the formation of organic substances requires the involvement of life processes. He also held that chemical phenomena are not governed by any laws peculiar to themselves but are explicable in terms of the laws of mechanics in operation throughout the universe. He introduced the terms exothermic and endothermic and rediscovered the action of microorganisms in the fixation of nitrogen in soils. His writings in the history of alchemy and chemistry are classics in the field. Berthelot published some 1,600 books and papers on various aspects of chemistry. His other works include translations of Greek, Syriac, and Arabic treatises on alchemy and chemistry. He also contributed many articles to La Grande Encyclopdie, which he helped to establish. The final period of his work was devoted to agricultural chemistry as well as to his historical writing. In 1889 he succeeded Louis Pasteur as secretary of the Acadmie des Sciences, Paris.