Dumas, Jean Baptiste Andre (1800-1884), a French chemist. He was noted for his researches in atomic weights, the composition and density of the atmosphere, and the theory of chemical types. Dumas studied in Geneva, Switzerland. In 1821 he went to Paris, where he served on the faculties of the College de France, Ecole de Medecine, and Ecole Centrale des Arts et Manufactures. He held several government posts.