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(75 per cent.) of fats may be obtained. The fatty extract 

 is saponified with alcoholic caustic soda, or with sodium 

 ethylate in etherial solution (Kossel and Obermiiller). In the 

 latter case saponification is rapid and complete in the cold, and 

 the separation of the soaps is easy. The cholesterine thus 

 obtained crystallises from 85 per cent, alcohol in thin rhombic 

 plates containing a molecule of water of crystallisation, or 

 from ether, chloroform, etc., in anhydrous silky needles melting 

 at 147 . In the animal kingdom this widely diffused cholesterine 

 is the only body of its type hitherto discovered, with the 

 exception of the Iso-cholesterine of melting-point 138 which, 

 according to Schulze, 1 is contained, along with cholesterine, 

 in wool-fat and must apparently be regarded as a cholesterine 

 excreted through the skin of the sheep. But in the vegetable 

 world the labours of many investigators 2 have brought to light 

 a large number of vegetable cholesterines which are very 

 similar in properties to cholesterine itself. In the work of 

 von Hauth 2 we find references to forty-eight such bodies obtained 

 from the most varied plants, their seeds, leaves, and juices, 

 and from vegetable oils and waxes. No fewer than thirty-one of 

 these, however, are isomeric with cholesterine and have melting- 

 points lying between 130 and 137 C, and recent work makes 

 it extremely probable that they are all more or less impure forms 

 of one substance, phytosterine. Burian 3 in 1897 for the first time 

 made a careful examination of a phytosterine extracted from 

 germinating wheat, which he called sitosterine. He purified 

 it with great care and obtained it back unaltered from pure 

 derivatives, and showed that its chemical properties formed 

 a complete parallel with those of cholesterine. Thus it forms 

 crystalline esters, a dibromide, and by loss of water a hydro- 

 carbon, as cholesterine itself. Windaus and Hauth, 3 again, 

 in 1907 made a study of the original phytosterine of Hesse 

 obtained from Calabar beans. They at once recognised that 

 Hesse's product was a mixture, and after much difficulty 

 succeeded in separating it into two bodies: (1) stigmasterine, 

 an alcohol C 3u H 4s O, melting-point 170°, which forms a character- 

 istic tetrabromide ; and (2) a phytosterine, present to the extent 

 of some 75 per cent, of the mixture, which proved identical with 



1 Ber. 6, 1075 (1873). 



2 For references see von Hauth, Inaug. Diss. Freiburg, 1907. 



3 See bibliography at the end of this article. 



