CHEVREUL , MICHEL EUGÈNE

Chevreul , Michel Eugène: translation

One of the longest-lived of all chemists, Chevreul, who was born at Angers in France, studied at the Collège de France (1803). He was an assistant to Antoine François de Fourcroy (1809), assistant at the Musée d'Histoire Naturelle (1810), then professor of physics at the Lycée Charlemagne (1813–30).

In 1810 Chevreul began a great program of research into fats, which was published in his book Recherches chimiques sur les corps gras d'origine animale (1823; Chemical Researches on Animal Fats). By acidification of soaps derived from animal fats and subsequent crystallization from alcohol he was able to identify for the first time various fatty acids: oleic acid, margaric acid (a mixture of stearic and palmitic acids), butyric acid, capric and caproic acids, and valeric acid. He recognized that fats are esters (called ‘ethers’ in the nomenclature of the day) of glycerol and fatty acids and that saponification produces salts of the fatty acids (soaps) and glycerol. In 1825 Chevreul and Joseph Gay-Lussac patented a process for making candles from crude stearic acid. Other fats investigated by Chevreul were spermaceti, lanolin, and cholesterol.

In 1824 Chevreul became director of the dyeworks for the Gobelins Tapestry, where he did important work on coloring matters, discovering hematoxylin in logwood, quercetin in yellow oak, and preparing the reduced colorless form of indigo. He also investigated the science and art of color with special application to the production of massed color by aggregations of small monochromatic dots, as in the threads of a tapestry.

Chevreul's later appointments were professor of chemistry at the Musée d'Histoire Naturelle (1830) and director there (1864). His other work included the discovery of creatine (1832) and studies on the history of chemistry.