CHOLESTERINE. 



77 



Fig. 17. 



matter of the skin, the liver, the spleen, the crystalline lens, and espe- 

 cially in the nerves, spinal cord, and brain, in which last it has been 

 found by Flint 1 in the proportion on the average of about one part per 

 thousand. Recent observations have shown that it is also a constituent / 

 of various articles of food, such as the yolk of egg, and even of many 1 

 vegetable products, as peas, beans, 3 olives, almonds, and Indian corn. 3 J 



Cholesterine is a cry stalliz able substance, insoluble in water, freely 

 soluble in ether, chloroform, boiling alcohol, and the volatile and fatty 

 oils. It is partially soluble in 

 watery solutions of the biliary 

 salts and of the saponified fats. 

 It is deposited from its alco- 

 holic or ethereal solution in 

 the form of very thin, color- 

 less, transparent, rhomboidal 

 plates, portions of which are 

 often cut out by lines of cleav- 

 age parallel to the edges of the 

 crystal. They frequently occur 

 deposited in layers, in which 

 the outlines of the subjacent 

 crystals show very distinctly 

 through the substance of 

 those placed above. It is 

 often found, in a crystalline 

 form, in the fluid of hydrocele 

 and other morbid exudations, in the contents of encysted tumors, and 

 in biliary calculi. Crystallized cholesterine melts at 145 (293 F.) ? 

 and distils unchanged in vacuo at about 360 (680 F.). Its solutions 

 rotate the plane of polarization to the left 32. 



If cholesterine be triturated with strong sulphuric acid, and chloro- 

 form added to the mixture, a blood-red color is produced, which after- 

 ward disappears by exposure to the air, passing gradually from red to 

 violet, blue, and green, the solution finally becoming colorless. 



Our knowledge with regard to the physiological relations of choleste- 

 rine is less definite than as to those of the true fatty substances. Its 

 abundant proportion in the brain and nerves, and its association in these 

 tissues with other important constituents, have led to the opinion that 

 it is an essential ingredient of the nerve substance. Whatever may be 

 its source in these organs, it is no doubt absorbed from the nervous 

 system by the blood, carried to the liver, and thence discharged with 



1 American Journal of the Medical Sciences, October, 1862. 



Hoppe-Seyler, Handbuch der Physiologisch- und Pathologisch-Chemischen, 

 Analyse. Berlin, 1870, p. 98. 

 3 Hardy, Principes de Chimie Biologique. Paris, 1871, p. 123. 



GHOLBSTERINE, from an Encysted Tumor. 



