SKETCH OF M. CHEVREUL. 549 



ancestry. His father, Michel Chevreul, a distinguished physician of 

 his day, according to Larousse's " Cyclopaedia " (born 1754, died 1845), 

 was ninety-one years old at the time of his death ; while the " Lan- 

 cet " finds somewhere nineteen additional years, and makes his age a 

 hundred and ten years. If discrepancies like this can occur in writing 

 exact biographies of our own times, why should we be surprised at the 

 variances in the legends of ancient days ? 



Michel Eugene Chevreul was born at Angers, France, where his 

 father was hospital physician and a professor in the Obstetrical School, 

 on the 31st of August, 1786. He studied the course of the Central 

 School of his native city, and then, when seventeen years old, went to 

 Paris, where he became associated with Vauquelin in the manufacture 

 of chemicals, and was made director of his laboratory. He was after- 

 ward, in 1810, selected by Vauquelin as preparator in the course of 

 Applied Chemistry at the Museum of Natural History. In 1813 he was 

 given the title of Officer of the University, and was placed in the chair 

 of Chemistry of the Lycee Charlemagne. In 1824 he was made special 

 Professor of Chemistry at the Gobelins factory, and director of the dye- 

 houses connected with that establishment. In 1826 he was admitted 

 to the Academy of Sciences, in the place of M. Proust, in whose favor 

 he had retired from the candidacy in 1816, when he had had an oppor- 

 tunity of being elected. In 1830 he succeeded his former master, Vau- 

 quelin, in the chair of Applied Chemistry in the Museum of Natural 

 History. He has been charged with the administration of the Jardin 

 des Plantes, where he has had occasion to defend the ancient preroga- 

 tives of the body he represented against the encroachments of the 

 political administration, and where he made a formal protest during the 

 siege of Paris against the barbarous bombardment of the buildings of 

 the institution. 



The enumeration of the discoveries that science owes to M. Che- 

 vreul would far pass the limits which it is possible to assign to this 

 sketch. The most important of them have been perhaps in the fields 

 of researches on fatty bodies of animal origin, and of colors, their con- 

 trasts, their harmonies, and the graduation of their shades. The " Re- 

 cherches chimiques sur les corps gras d'origine animal " ("Chemical Re- 

 searches on Fatty Bodies of Animal Origin "), on which the foundation 

 of his reputation was laid, appeared in 1823. In this work the author 

 developed his new ideas on the relations of fatty bodies and the ethers, 

 and propounded the first exact theory of saponification, whether pro- 

 duced by acids or by bases, by showing that either of those two classes 

 of bodies tend to speed the decomposition of fat-substances in acids and 

 in glycerine, through the absorption of a certain number of equivalents 

 of water. The same decomposition takes place spontaneously but slowly 

 in the open air, and is the cause of the rancidity of fats. The water 

 absorbed in the course of the transformation contributes to the forma- 

 tion of the resultant fat-acid, and the glycerine is separated. When a 



