THE CHEMISTRY OF CHOLESTERINE 91 



the sitosterine of Burian. With this discovery in mind, a glance 

 at the tables given by von Hauth shows that most of the 

 phytosterines that have been described with melting-points of 

 130 to 1 37 must be phytosterine mixed with some impurity. 

 We may say, then, that the higher plants contain as their typical 

 cholesterine constituent, phytosterine, an unsaturated alcohol, 

 isomeric with cholesterine, of melting-point 137 . 



Its empirical formula is difficult to settle exactly by analysis. 

 The results of Chevreul, Couerbe, Marchand, and others 

 pointed to the proportions C 27 H 46 ; Gerhardt, however, sug- 

 gested C 2C H 4 40, and for many years this was adopted. Ober- 

 muller 1 attempted to decide the question by accurate analysis of 

 pure derivatives, and his work again seemed to confirm the 

 formula C 27 H 46 ; but in 1894 Mauthner and Suida, on reviewing 

 all the older analyses, pointed out that the carbon values in 

 particular were always higher than would be required for this 

 formula, and that they corresponded very much better with a 

 formula Car^O. Further, such an assumption would remove 

 difficulties they had found in assigning formulae to the hydro- 

 carbons derived from cholesterine by the loss of the elements 

 of water. They accordingly analysed carefully dried and 

 purified cholesterine and its compounds, and in every case 

 the results appeared to confirm their conclusion. For instance, 

 for cholesterine they found : 



I. II. III. IV. V. C 27 H w O C^H^O 



C . . . 84*07 84*04 84*00 84*12 84*02 83*96 84*37 

 H. . . 12*24 — n*79 n'85 11*84 11*92 11*46 



Dried at 110° 130° 115" 125°— 130° 



and when it is remembered that the carbon values in organic 

 analysis are usually lower than those required by theory, it will 

 be seen that there is good reason for the adoption of the lower 

 hydrogen formula. All the modern workers on the subject, 

 however, still use CziH i6 as the formula for cholesterine ; 

 and to avoid confusion, therefore, it will be employed in the 

 present paper. 



Chemically cholesterine is an unsaturated secondary alcohol. 

 It combines with two atoms of bromine, forming the dibromide, 



1 Zeit. Physiol. Ch, 15, 37. 



