BRONGNIART, ALEXANDRE

born Feb. 5, 1770, Paris, Fr. died Oct. 7, 1847, Paris French mineralogist, geologist, and naturalist, who first arranged the geologic formations of the Tertiary Period (from 66.4 to 1.6 million years ago) in chronological order and described them. Brongniart was appointed professor of natu ral history at the cole Centrale des Quatre-Nations, Paris, in 1797, and in 1800 he was made director of the Svres Porcelain Factory, a post he retained until his death. He worked to improve the art of enameling in France and made Svres the leading such factory in Europe. Among Brongniart's early papers is the Essai d'une classification naturelle des reptiles (1800; Essay on the Natural Classification of Reptiles), in which he divided the class Reptilia into four orders: Batrachia (now a separate class, Amphibia), Chelonia, Ophidia, and Sauria. He made the first systematic study of trilobites, an extinct group of arthropods that became important in determining the chronology of Paleozoic strata (from 540 to 245 million years ago). In 1804 he began a study of fossil-bearing strata in the Paris Basin with the French naturalist Georges Cuvier. Summarizing this study in his Essai sur la gographie minralogique des environs de Paris, avec une carte gognostique et des coupes de terrain (1811; Essay on the Mineralogical Geography of the Environs of Paris, with a Geological Map and Profiles of the Terrain), Brongniart helped introduce the principle of geologic dating by the identification of distinctive fossils found in each stratum and noted that the Paris formations had been created under alternate freshwater and saltwater conditions. As professor of mineralogy (182247) at the National Museum of Natural History, Paris, he turned his attention to ceramic technology; his last major work was Trait des arts cramiques (1844; Treatise on the Ceramic Arts).