Contribution of Chevreul to lipid chemistry

Michel Eugène Chevreul entered at 17 the laboratory of Vauquelin, at the Museum. He began his investigations on animal fats in 1811. They appear as yet the most complete and the best executed experiments found in all chemistry. For the first time, he combined fractional solution, crystallization, distillation, melting point determination, and ultimate analysis. All started with the isolation of an acid and solid substance, “margaric acid”, the first of a long list of fatty acids isolated from various fats. Studying saponification, he determined that “anhydrous glycerine” was combining with water. After studying human gallstones, he discovered “cholesterine” (cholesterol). From whale spermaceti, he described “cetin” (mainly cetyl palmitate), containing no glycerol. He isolated from sheep fat a new acid he named “stearic acid”. This component was proposed in a joint patent by Chevreul and Gay-Lussac (1825) for the fabrication of very efficient candles. He discovered several volatile fatty acids in cow and goat butter (from C4 to C10). His master work (Recherches chimiques sur les corps gras d’origine animale, 1823b) contains his experimental procedures and his theoretical conclusions on the nature of fats, it may be considered as the first treatise on lipochemistry.