The French chemist Jean Baptiste André Dumas (1800-1884) worked in the field of organic chemistry and developed the "type" theory of organic structure.

On July 14, 1800, Jean Baptiste Dumas was born at Alais. In his youth he was apprenticed to an apothecary. In 1816 he moved to Geneva and studied physiological chemistry in the laboratory of A. Le Royer. In Geneva, Dumas met the famous scientist Alexander von Humboldt, who persuaded Dumas to move to Paris, where he would find greater scientific opportunities. This he did in 1823, and he was engaged as a lecture assistant in chemistry at the École Polytechnique; he became professor of chemistry in 1835. During this period Dumas began to work on his major book, Treatise on Chemistry, and he also participated in the founding of the Central School for Arts and Manufactures.

In 1830 Dumas challenged the so-called dualistic theory of the great Swedish chemist...