CHOLESTBRIN. 275 



OHO LE3TERIN. C 37 H 32 O. 



Chemical Relations. 



Properties. This body, formerly known as biliary fat, separates 

 from its solutions in nacreous scales containing 2 atoms of water ; 

 examined under the microscope, these crystals appear in very thin 

 rhombic tablets, whose obtuse angles = 100 30", and whose acute 

 angles = 7^30'; it fuses at 145, solidifying again, and becoming 

 perfectly crystalline at 135; it may be distilled in vacuo at 360 

 without undergoing decomposition ; it becomes electrical on fric- 

 tion, is perfectly insoluble in water, but dissolves in 9 parts of 

 boiling alcohol, from which the greater part again separates on cool- 

 ing ; it is also slightly soluble in soap-water, and more freely 

 in the fatty oils and taurocholic acid ; it is inflammable, arid 

 burns with a smoky flame. Treated with concentrated sulphuric 

 acid it assumes a red tint at 60, and is converted, with the 

 loss of water, into three probably polymeric carbo-hydrogens, which 

 their discoverer, Zwenger,* has named cholesterilins. If choles- 

 terin be heated with concentrated phosphoric acid to its melting 

 point, there are formed two carbo-hydrogens, isomeric with 

 the cholesterilins, to which Zwengerf has applied the name 

 of cholesterones. By prolonged boiling with concentrated nitric 

 acid, it becomes first converted into a resinous mass, which, by pro- 

 longed digestion, is resolved (RedtenbacherJ) into acetic, butyric, 

 caproic, oxalic, and cholesteric acids (see page 122). A portion 

 of the hydrogen may be abstracted from cholesterin by chlorine or 

 bromine, of which an equivalent quantity takes the place of the 

 hydrogen thus removed. It is riot decomposed by concentrated 

 alkalies, even when the mixture is submitted to prolonged heat. 

 On dry distillation it leaves a charcoal, and yields an oily distillate, 

 which after rectification with water evolves an agreeable odour, 

 resembling that of the Geranium. 



Composition. Cholesterin has been analysed by Marchand, 

 Schwendler and Meissner, and subsequently by Payen,|| with toler- 

 ably similar results, which have led to the establishment of the 

 above formula, C 37 H 32 O. As we have not yet succeeded in com- 



* Ann. d.Ch. u. Phann. Bd. 66, S. 5-13. 



t Ibid. Bd. 69, S. 347-354. 



J Ibid. Bd. 57, S. 162-170. 



Journ. f. pr .Ch. Bd. 16, S. 37-48. 



II Ann. de Chim. et de Phys. 3 Ser. T. 1, p. 54. 



