Jean Baptists Andre Dumas

Born July 14, 1800, in Ales; died April 11, 1884, in Cannes. French chemist. From 1835 to 1840 he was a professor at the Ecole Polytechnique; from 1829 to 1852, at the Ecole Centrale des Arts et Manufactures; and beginning in 1839, at the Ecole de Médecine in Paris. In 1832 he organized a chemical teaching laboratory, where he gave instruction based on the ideas of J. von Liebig. In that year he also became a member of the Paris Academy of Sciences; in 1840 he became a fellow of the Royal Society in London; in 1845, a foreign corresponding member of the St. Petersburg Academy of Sciences; and in 1880, a member of the Berlin Academy of Sciences.

In 1826, Dumas published a method of determining vapor density. Using it to find the atomic weights of a number of elements, he did not differentiate clearly between atoms and molecules, causing him to draw erroneous conclusions. He established the composition of esters and, in collaboration with the French chemist P. Boullay, proposed the idea that ethyl alcohol and its ethers and esters are derivatives of ethylene, which J. Berzelius called etherin. Dumas regarded it as a base, like ammonia. These views were developed in the theory of radicals. In 1839, with the French chemist E. M. Peligot, he established that fats are esters. He formulated an empirical law of replacement of hydrogen by chlorine in organic compounds (1834). In 1839 he set forth the assumption that all elements in chemical compounds can be replaced by other elements. In 1843 he established the existence of the first homologous series in organic chemistry, the formic acid series. In 1830 he proposed a method for volume determination of nitrogen in the most diverse organic compounds. He studied the chemical composition of blood and the effect of food on the chemical composition of milk from different animals. He also dealt with problems of sericulture (1857) and took part in measures to combat phylloxera (1873).