Thénard, Louis Jacques

Thénard, Louis Jacques (lwē zhäk tānär`), 1777–1857, French chemist. He became professor at the Collège de France (1802), dean of the Faculty of Sciences, Paris (1821), chancellor of the Univ. of Paris (1832), and was made a baron in 1825. He collaborated with Gay-Lussac in studies of boron, chlorine, iodine, and potassium, worked on esters, and discovered (1799) hydrogen peroxide and Thénard's blue, an ultramarine coloring used for porcelain. He wrote many scientific papers and a standard textbook, Traité de chimie élémentaire (4 vol., 1813–16).