Dumas, Jean Baptiste Andrц?

Dumas, Jean Baptiste Andrц? (Dumas, Jean Baptiste Andrц?) (1800-1884), French chemist. Born July 14, 1800 in Ale. Studied Aptekarskii case, in 1816 went to Geneva, where he worked as an assistant pharmacist in a pharmacy, which had a laboratory. Engaged in the University of Geneva, became fascinated with chemistry and physiology. In 1823, on the advice of Alexander von Humboldt, who drew attention to the young scientist, he moved to Paris. He worked as taxidermist at the Ecole Polytechnique, he taught chemistry in high school. In 1832, succeeded Gay-Lussac's law at the Sorbonne, remained there until 1868. At the same time worked at the Ecole Polytechnique (since 1835 a professor), the Central School of Arts and Crafts (1829-1952), Medical School (from 1939). After the February Revolution of 1848 became a member of the National Assembly, then minister of agriculture and trade. He was a member of the Senate (1856), president of the Municipal Council of Paris (1859), head of the mint (1868). After 1870 withdrew from political activity and devoted himself entirely to science.

Dumas' works are predominantly in the field of organic chemistry. In 1826, he proposed a way to determine the density of vapors of various substances. In 1827, determined the composition of acetone and esters, together with P. Bulle suggested that ethyl alcohol and its esters - are derivatives of ethylene. On this basis, they had constructed a theory eterina, which can be considered a precursor of the theory of radicals. In 1837, Dumas and Liebig in a joint paper identified organic chemistry as the chemistry of complex radicals - groups of atoms that remain unchanged during the chemical reaction.

In 1830 Dumas suggested method for determining nitrogen in organic compounds (Dumas method). In the same year, began experiments on the substitution of hydrogen atoms, halogen-organic compounds. Acting chlorine on acetic acid, has received a new substance - trichloroacetic acid. This discovery has dealt a blow to the dualistic theory of Berzelius, according to which the electronegative chlorine could not replace the electropositive hydrogen. January 13, 1834 Dumas made a presentation at the Academy of Sciences, stating that "chlorine has an amazing ability to attract to itself and to replace its hydrogen atom by atom '. Combining the data obtained, Dumas metalepsii formulated rules of thumb (from the Greek. 'replace'). In 1840 he (together with A. Regnault) proposed to consider the chemical compounds as the products 'substitution' of atoms a few basic compounds, called 'types'. The mechanical theory of 'types' together with the old theory of radicals due to the works of Laurent, Gerard and others. resulted in 50-ies 19. to the theory of radicals. In 1843, Dumas was informed of the existence of the homologous series - formic acid and deduced general rules for the homologous series in organic chemistry.

It should be noted, and such works of Dumas, as the receipt of methanol from mint oil (1825), extraction of anthracene from coal tar (1831), establishing (jointly with E. Peligot) the fact that fats are esters. In addition, the scientist worked on hematopoiesis, determining the chemical composition of blood, anti-phylloxera (vine pest).

Dumas - author of a textbook on chemical engineering, chemistry course in the annex to the craft "(Traitц? de chimie appliqueц? aux arts, v. 1-8, 1828-1846) and reprinted several times Lectures on the Chemical Philosophy, which outlined the development of chemical theories. In 1840 Dumas was elected a member of the Royal Society of London, in 1880 - the Berlin Academy of Sciences, in 1845 - a foreign member of the St. Petersburg Academy of Sciences. In 1859, became president of the French Chemical Society.

Dumas died in Cannes, April 11, 1884.