550 THE POPULAR SCIENCE MONTHLY. 



fatty substance is submitted to the action of a strong acid, the decom- 

 position takes place instantaneously, because the acid separates the 

 glycerine and unites with it. If, on the other hand, the action is ac- 

 complished by means of an energetic base, the base determines the 

 formation of a fat-acid, and combines with it, so as to leave the gly- 

 cerine isolated. Glycerine had been discovered by Scheele in 1775, 

 but, until M. Chevreul's experiments, was regarded as only accidentally 

 present in some fats ; and to M. Chevreul is due the discovery that it 

 is always separated in the saponification of fats, and that those bodies 

 are now regarded as salts, formed of glycerine as a base, combined 

 with some acid. This theory led up to the invention of star-candles, 

 a boon to mankind, of the value of which the present generation, with 

 its gas-lights and petroleum-lamps, can have no conception. For this 

 discovery M. Chevreul was awarded the grand prize of twelve thou- 

 sand francs founded by the Marquis d'Argenteuil, in conferring which 

 the Societe d'Encouragement pour lTndustrie Nationale declared with 

 justice that it was only registering the opinion of all Europe concern- 

 ing researches which might serve as models to all chemists. M. Che- 

 vreul, it may be added, never thought of turning his discoveries to his 

 personal profit, but gave them freely to the world, and was satisfied 

 with being a student of science. 



M. Chevreul's researches in coloring-matters at the Gobelins fac- 

 tory and at the Museum gave occasion to the publication of " Le- 

 90ns de chimie appliquee a la teinture " (" Lessons on the Applica- 

 tion of Chemistry to Dyeing," 1828-1831) ; of a memoir on the law of 

 the simultaneous contrast of colors, and on the arrangement of colored 

 objects according to that law in its relations to painting (" Sur la loi 

 du contraste simultane des couleurset sur l'assortiment des objets colo- 

 rees, considere d'apres cette loi dans ses rapports avec la peinture," 

 1829), and of a memoir on colors and their application in the indus- 

 trial arts (" Des couleurs et de leur application aux arts industriels a 

 l'aide des cercles chromatiques," 1864) ; works embodying novel ideas, 

 the application of which in manufactories and workshops has been 

 attended with important results. M. Chevreul was much grieved 

 when, in his advanced age, the management of the Gobelins factory 

 placed him on the retired list ; but, in order to appease his feelings, 

 he was allowed to retain his appointment with the full salary attached 

 to it. In 1879 he was retired from the directory of the Museum, but 

 was permitted to retain his chair as professor. 



Among the honors that have been accorded to him are membership 

 of the Royal Society ; President of the Agricultural Society ; Com- 

 mander, Grand Officer, and Grand Cross of the Legion of Honor ; and 

 other memberships and decorations at home and abroad. He was a 

 member of the International Juries at the Expositions of London and 

 Paris. In September, 1872, the French Academy of Sciences pre- 

 sented him with a medal in anticipatory commemoration of the fiftieth 



