Background

Chevreul was born on August 31, 1786, at Angers, where his father was the director of the medical school. Chevreul's birth certificate, kept in the registry book of Angers, bears the signature of his father, grandfather, and a great-uncle, all of whom were surgeons.

Education

After his early education in Angers, Chevreul went to Paris in 1803 to study chemistry under Nicolas Vauquelin at the Muséum d’Histoire Naturelle, thereby beginning a career of nearly ninety years at that institution.

Career

Chevreul rose rapidly through the scientific ranks during the 1820’s and 1830’s, his two most important positions being those of professor of chemistry at the Museum from 1830 and director of dyeing at the Manufactures Royales des Gobelins, the national tapestry workshop, where he succeeded Claude Berthollet in 1824. For nearly sixty years he taught courses in chemistry at these two institutions. He was director of the Museum from 1864 to 1879. Chevreul became a member of the Académie des Sciences in 1826 and was elected to the presidency in 1839 and again in 1871.

Chevreul displayed his versatility in his many books and papers in history, philosophy, and psychology. He contributed many papers to the Journal des savants on a variety of subjects, of which the most important were his studies on alchemy, the early history of chemistry, and the history of medicine. He wrote two books on these subjects: Histoire des connaissances chimiques (1866) and Résumé d’une histoire de la matière (1878). Chevreul’s interest in psychology culminated in 1853, when the Académie des Sciences appointed him chairman of a committee to investigate séances and other psychic phenomena, as well as the use of divining rods and exploring pendulums in locating water or mineral deposits. He published an exposé of psychic phenomena and of these devices in his De la baguette divinatoire (1854). Chevreul also produced many papers on philosophy and on scientific method. His ideas on scientific method found their most complete expression in his De la méthode a posteriori expérimentale (1870).

Chevreul’s scientific researches on dyes, color theory, and the chemistry of natural fats all stemmed from his association with Vauquelin at the Museum. Vauquelin introduced Chevreul to the study of organic substances in 1807 by having his student investigate plant dyes. This was Chevreul’s first important series of researches. He isolated and examined several natural dyes. On the completion of these studies in 1811 Chevreul turned to the chemistry of natural fats as his next project.

This study occupied him until 1823, and he returned to the study of dyes upon his appointment the following year as director of dyeing at Gobelins. Chevreul’s immediate task at Gobelins was to work on the improvement of color intensity and fastness in wools. He had been selected for this position because he was an outstanding chemist; and his initial studies were on the chemical aspects of dyes and dyeing, attempting to place the art of dyeing on a more rational basis than the complicated and empirical procedures then employed. He embarked upon a thorough study of the properties of natural dyes and between 1838 and 1864 published several important papers in the Mémoires de l’Académie des Sciences, reviewing the chemistry and technology of dyeing. These papers and his two-volume Leçons de chimie appliquée à la teinture (1829-1830) rendered an important service to the dye industry during the years prior to the advent of synthetic dyestuffs. In addition to the chemical aspects of dyeing Chevreul made an intensive study of the principles governing the contrast of colors, which resulted in his monumental De la loi du contraste simultané des couleurs (1839), the most influential of his many books.

After many experiments on color contrast Chevreul formulated for the first time the general principles and effects of simultaneous contrast, the modification in hue and tone that occurs when juxtaposed colors are seen simultaneously. He also continued to be acclaimed for the discovery of several important principles governing color behavior. Finally, one important aspect of Chevreul’s color studies must be mentioned: their influence in the fine arts. The neo-impressionist painters derived their methods of painting from Chevreul’s principles, applying separate touches of pure colors to the canvas and allowing the eye of the observer to combine them.

While his color studies made him one of the most influential scientists of the nineteenth century, Chevreul’s work on the chemical nature of the natural fats established him also as one of the major figures in the early development of organic chemistry. When he began these studies in 1811, research in organic chemistry was in a very rudimentary state. Chemists had isolated many materials from animal and plant sources and had investigated their chemical properties. These immediate principles were of a more complex nature than inorganic bodies and supposedly were the products of special forces in the organism, forces that were different from those in the inanimate world. The whole subject of animal and vegetable chemistry was in a state of confusion. Among the prerequisites to a removal of this confusion was a means of determining the elementary composition of organic materials, which were just beginning to succumb to elementary analysis when Chevreul embarked upon his investigation of animal fats. This was the first area of organic chemistry to receive a thorough examination, and Chevreul’s researches between 1811 and 1823 resulted in the natural fats’ becoming the first class of naturally occurring organic substances whose fundamental character was understood. While animal fats and vegetable oils had been utilized since antiquity, especially in the making of soaps, chemists had accomplished little in clarifying the nature of the saponification process or in understanding the chemical nature of the ingredients and products.

Chevreul isolated, studied, and named many of the members of the fatty acid series from butyric to stearic acid. By 1816 he had established that all animal fats yielded both fatty acids and glycerol on saponification with alkali, the glycerol having earlier been observed by Scheele as a conversion product of several fats and oils. After his discovery of the fatty acids Chevreul attacked the saponification process itself, and by a masterly interpretation of reactions, he unraveled its nature.

In his later years he continued to work at the Museum and to attend meetings of the Academy, presenting his last communication to this body in 1888, when he was 102. Because of his achievements and great age, his colleagues accorded him great respect and regarded him as one of the most distinguished scientists of the century.

Achievements

• Chevreul elucidated the chemical composition of animal fats and whose theories of color influenced the techniques of French painting. Prior to his work there was no method of submitting the products of analysis to a system of tests to determine whether the products were pure principles. He applied such a system of tests in his study of fats, which thereby became the first exact model of analytical research in organic chemistry.
  
  In the opinion of his contemporaries, Chevreul’s studies constituted the best work done in organic chemistry, wherein quantitative and atomic relations had been established, constitutions discovered, relationships discerned, and the way shown toward the clarification of the difficulties of organic chemistry.

Works

More photos

• book

  • Recherches Chimiques Sur Les Corps Gras d'Origine Animale

    (French Edition)

    1823
  • Histoire des Connaissances Chimiques

    (French Edition)

    1866
  • De la Méthode A Posteriori Expérimentale Et de la Généralité de Ses Applications

    (French Edition)

    1870
  • The Laws of Contrast of Colour: And Their Application
  • The Principles of Harmony and Contrast of Colours, and Their Applications to the Arts

Membership

• Académie des Sciences , France

  1826

Personality

Chevreul was very regular and methodical throughout his long life. His countrymen admired the centenarian for his abilities in many different fields.

Connections

Chevreul married Sophie Davallet, the daughter of a tax official, in 1818. She died in 1862 and Chevreul forsook almost all social life, living his remaining years in the Museum and going out only to scientific meetings.

Spouse:

Sophie Davallet

References

• Écrits alchimiques de Michel-Eugène Chevreul French Edition
  2016
• Michel Eugène Chevreul: Pioneer of Organic Chemistry
  1962
• Oeuvres Scientifiques De Michel-Eugène Chevreul: Doyen Des Étudiants De France 1806-1886 French Edition