Michel Eugène Chevreul

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Michel Eugène Chevreul (August 31, 1786 – April 9, 1889) was an important French chemist whose work with fatty acids led to early applications in the fields of art and science. He is credited with discovering margarine and designing an early form of soap made from animal fats and salt. He also lived to 102 and was a pioneer in the field of gerontology.

He was born in Angers, where his father was a physician. His birth certificate kept in the registry book of the town bears the signature of his father, grandfather and a great-uncle, all of whom were surgeons.

At about the age of seventeen he went to Paris and entered LN Vauquelin's chemical laboratory, afterwards becoming his assistant at the Muséum National d'Histoire Naturelle in the Jardin des Plantes. In 1813 he was appointed professor of chemistry at the Lycée Charlemagne, and subsequently undertook the directorship of the Gobelins tapestry works, where he carried out his researches on colour contrasts (De la loi du contraste simultané des couleurs, 1839; the 1854 English translation is titled The Principles of Harmony and Contrast of Colors). In 1826 he became a member of the Academy of Sciences, and in the same year was elected a foreign member of the Royal Society of London, whose Copley Medal he was awarded in 1857.

Chevreul in 1886

He succeeded his master, Vauquelin, as professor of organic chemistry at the natural history museum in 1830, and thirty-three years later assumed its directorship also; this he relinquished in 1879, though he still retained his professorship. A gold medal was minted for the occasion of Chevreul's 100th birthday in 1886, and it was celebrated as a national event. Chevreul received letters of commendation from many heads of state and monarchs, including Queen Victoria. He had a series of recorded meetings with Felix Nadar, with Nadar's son Paul taking photographs, making up the first photo-interview in history. Overall, it was a fitting tribute to a man who lived through the entire French Revolution and lived to see the unveiling of the Eiffel tower.

Ironically, Chevreul began to study the effects of ageing on the human body shortly before his death at the grand age of 102 which occurred in Paris on 9 April 1889. He was honoured with a public funeral. In 1901 a statue was erected to his memory in the museum with which he was connected for so many years.

His scientific work covered a wide range, but his name is best known for the classical researches he carried out on animal fats, published in 1823 (Recherches sur les corps gras d'origine animale). These enabled him to elucidate the true nature of soap; he was also able to discover the composition of stearin, a white substance found in the solid parts of most animal and vegetable fats, and olein, the liquid part of any fat, and to isolate stearic and oleic acids, the names of which were invented by him. This work led to important improvements in the processes of candle-manufacture. Chevreul was a determined enemy of charlatanism in every form, and a complete sceptic as to the "scientific" psychical research or spiritualism which had begun in his time (see his De La baguette divinatoire, et des tables tournantes, 1864).

Chevreul was also influential in the world of art. After being named director of the dye works at the Gobelins Tapestry Works in Paris, he received many complaints about the dyes being used there. In particular, the blacks appeared different when used next to blues. He determined that the yarn's perceived color was influenced by other surrounding yarns. This led to a concept known as simultaneous contrast.

Chevreul's work addressed painting with the aim of reproducing nature as closely as possible, by separating effects of light and chiaroscuro, which the artist must repeat, from those of color contrast, which would apply to the paint's own color and so be exaggerated. Yet the color principle subsequently had a great influence on the birth of Neo-Impressionism and Orphism.

[edit] Works

De la loi du contraste simultané des couleurs et de l'assortiment des objets colorés (1839), translated into English by Charles Martel as The principles of harmony and contrast of colours (1854) (sample pages from third edition), ISBN 0887400906