BILE CONCRETIONS. CHOLESTERIN. 445 



the lime-pigment stones are not found very often in man, but often in 

 oxen. 



The pigment-stones are generally not large in man, but in oxen and 

 pigs they are sometimes found the size of a walnut or even larger. In 

 most eases they consist principally of calcium-bilirubin with little or no 

 biliverdin, and they also often contain very small amounts of cholic acids. 

 Sometimes also small black or greenish-black, metallic-looking stones 

 are found, which consist chiefly of bilifuscin along with biliverdin. Iron 

 and copper seem to be regular constituents of pigment-stones. Man- 

 ganese and zinc have also been found in a few cases. The pigment-stones 

 are generally heavier than water. 



The cholesterin-stones, whose size, form, color, and structure may vary 

 greatly, are often lighter than water. The fractured surface is radiated, 

 crystalline, and frequently shows crystalline, concentric layers. The 

 cleavage fracture is waxy in appearance, and the fractured surface when 

 rubbed by the finger-nail also becomes like wax. By rubbing against 

 each other in the gall-bladder they often become faceted or take other 

 remarkable shapes. Their surface is sometimes nearly white and wax- 

 like, but generally their color is variable. They are sometimes smooth, 

 in other cases they are rough or uneven. The quantity of cholesterin 

 in the stones varies from 642 to 981 p. m. (RITTER x ). The cholesterin- 

 stones sometimes contain variable amounts of lime-pigments, which may 

 give them a very changeable appearance. 



Cholesterin. The formula for this body, although not positively 

 determined, is generally given as C2?H46O (OBERMULLER) or C2?H44O 

 (MAUTHNER and SUIDA). 



Because of the fact that from cholesterin, hydrocarbons which 

 have been called cholesteriline, cholesterone and cholesterilene, can be 

 prepared in different w r ays, it was believed that a certain analogy exists 

 between the cholesterin and the terpenes. The color reactions as 

 well as the recent investigations on the constitution of cholesterin indicate 

 that this body belongs to the terpenes. 



The constitution of cholesterin has not been completely determined, 

 although we have the very laborious and thorough investigations of 

 many workers of whom we especially mention MAUTHNER and SUIDA, 

 WINDAUS, STEIN, DIELS and ABDERHALDEN.S From these investigations 

 we conclude that cholesterin is a monoatomic, unsaturated, secondary 

 alcohol whose hydroxyl group exists in a hydrogenized ring, between 



1 Journ. de Tanat. et de la physiol. (Robin), 1872. 



2 The literature on cholesterin can be found in Windaus, Arch. d. Pharm., 246, 

 Hft. 2, and in Abderhalden's Bioch. Handlexikon, Bd., 3, and also in Glikin, Bioch. 

 Centralbl., 7, 372-377. 



