Michel Eugène Chevreul

Michel Eugène Chevreul ( born August 31, 1786 in Angers, France, † April 9, 1889 in Paris) was a French chemist and founder of the chemistry of fats and the modern theory of colors.

Life

Chevreul's father was a highly respected surgeon. He attended from 1799, the Central School of Angers where he learned Latin, Greek, Italian, mineralogy, physics and chemistry. In 1803 he moved to Paris and studied with Antoine François de Fourcroy and Louis Nicolas Vauquelin -. In 1804, Vauquelin was appointed Professor of Applied Chemistry at the Muséum national d' histoire naturelle and Chevreul became his assistant. In 1813 Chevreul was professor of natural sciences at the Lycée Charlemagne.

In 1818 he married Sophie Davallet.

Chevreul filed a patent for non-drip candles and, together with Joseph Louis Gay -Lussac in 1824, a candle factory. In 1824 he was of Louis XVIII. appointed director of a tapestry - dyeing. Besides, he continued to teach at the Lycée Charlemagne and worked on a two-volume work for organic analysis.

1826 Chevreul was a member of the Académie des Sciences. 1830 Chevreul made ​​on a book about the theory of color, but it was moved only in 1839 ( De la Loi du Contraste simultaneous des Couleurs ). In 1832 he became a member of the Societe Royale d'Agriculture and was its president since 1849. In 1860 he was elected a member of the Leopoldina. In 1862 his wife died.

On the occasion of his 100th birthday, he was visited by photographer Nadar, what is considered the first photo reportage of the story.

Until his 102nd birthday, he wrote articles and regularly attended meetings of the Academie de Science. In 1889 he died at the age of 102 years.

Important academic stations at a glance

Significant students Chevreul

• Charles Frédéric Gerhardt
• Stanislao Cannizzaro

Scientific achievements

Indigo

Chevreul isolated with 20 years several plant dyes. At this time, yet were no simple separation methods, his work has been associated with great effort. When heating indigo he was able to prove in pure form in the steam and then resublimierten solid indigo and also discovered the reduced, colorless form of indigo.

Fettchemie

In 1811 Chevreul received a potassium soap made from lard for examination. He treated the soap with acid and was isolated from this reaction, an acidic, pearly connection. He had the first fatty acids isolated and named this first margarine (Greek: μαργαρίτηξ = pearl, margarine), later also acidic and acidic magarique Stearique (stearic acid ). Chevreul isolated a second fatty acid, which he called acidic Oleique (oleic acid).

Later Chevreul investigated further Fats: goose fat, cow butter, goat butter, sheep fat, Jaguar fat and fats of dolphins. He noted that there are (appointed by him, stearine (Greek: στέαρ = tallow) ) solid and liquid ( Élaine (Greek: έλαιον = oil) ) are fats. He called the fatty acid derived from goat cheese caproic acid (Latin capra = goat) from the butyric acid, lanolin from wool grease (Latin lana = wool). The insulated from the Delphi oil fatty he called Delphi acid, later as Phokäersäure. In the saponification of fats, another by-product appeared alongside the fatty acids. Even Carl Wilhelm Scheele had tasted this byproduct of saponification and found it sweet. Chevreul investigated the chemical bond between the fatty acid and the sweet substance ( the Chevreul Glycérine ( glycerol) called ). Chevreul found that in the reaction of fatty acids with glycerol to form fats, water was removed. After Louis Jacques Thénard he called the bond between glycerol and fatty acids ether third order ( the exact binding mode of the ester was then still unknown). Chevreul had the right bonding detected in his work on those later chemists were able to build.

In addition to the fatty acids Chevreul was a fat, which could not be saponified. He called it cholesterols ( cholesterol). In spermaceti he found no glycerin, although it was also possible to saponify. He found a neutral substance, which he called Ethal ( cetyl alcohol ).

Business start-up candles

Chevreul had in common with Gay-Lussac a patent for the production of stearic acid. With this patent, he and Gay -Lussac a candle factory in Paris. These new candles on Stearinbasis developed no strong soot and no toxic gases ( acrolein) as then in use tallow candles.

Since the company was very small, the commercial success did not come first. Adolphe de Milly, a student of Chevreul, and M. Rider bought the patent of Chevreul and soon founded a highly successful Kerzenmanufaktur. For living rooms, these candles one of the most important lighting means were.

Color theory

In addition to Newton Optics and Goethe's color theory the work of Chevreul De la Loi du Contraste simultaneous des Couleurs is one of the most important works on color theory. Chevreul developed from the three primary colors red, yellow, blue, a color wheel, with 23 mixed colors for each color, so that a circle of 72 colors was born. Also for the gradual brightening and darkening, he developed color scales.

• Simultaneous contrast

If one of two very similarly colored fabrics or pieces of paper with slight brightness and color variations directly to each other, the result is a strong color contrast for the viewer.

• Of successive contrast

Fixes to various areas of color individually, the surface changes color, the complementary color appears even more by the eye.

By the spatial juxtaposition of pigments he determined systematically the maximum simultaneous contrast and thereby received a color series of counter pairs. This is today the range of school color boxes (DIN 5023 ). He had gone through his major works great influence on the development of art and industry of modern painting (among Georges Seurat ).

Significant personality

At the Eiffel Tower, his name was immortalized as a significant figure, see: The 72 names on the Eiffel Tower.

Writings

• De La Loi You Contraste simultaneous Des Couleurs Et De L' Objet assortment Des Colores. Considere D' Apres Cette Loi Dans Ses repeat Avec La Peinture, Les Tapisseries Des Gobelins, Beauvais Pour Les Tapisseries De Meubles Les Tapis, La Mosaique, Les Vitraux colorees, L' Impression Of ETOFFES, L' Imprimerie L' Enluminure, La Décoration Des edifices, L' Habillement Et L' Horticultur. Pitois - Levrault, Paris 1839.
• Des couleurs et de leurs application aux arts Industrial and à l'aide of cercles chromatiques. J. B. Baillière et fils Libraires, Paris, 1864.