72 PHYSIOLOGICAL CHEMISTRY. 



sure, passing gradually from red to violet, blue, and green, the liquid 

 finally becoming colorless. (Hoppe-Seyler.) 



Cholesterine is a constant ingredient of the bile, in which it occurs 

 in the proportion of 0.5 part per thousand, and which seems to be its 

 principal channel of exit from the system. It is also present in the 

 sebaceous matter of the skin, and appears in considerable quantity in 

 accidental deposits or exudations, such as biliary calculi, the fluid of 

 hydrocele, and the contents of various encysted tumors. It exists in 

 the blood, the liver, the spleen, the crystalline lens, and especially 

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

 by Flint* in the proportion of about one part per thousand. It is also 

 present in the yolk of egg, and in the spermatozoa of all the higher 

 and lower animals, f It is not confined to the animal body, but is found 

 in many vegetable structures, such as wheat, Indian corn, peas and beans, 

 olives, almonds, young buds, and mould-fungi. 



The physiological relations of cholesterine are very obscure, as com- 

 pared with those of true fatty substances. Notwithstanding its wide 

 distribution in the animal system, in nutritious substances, in the blood, 

 and in such important organs as the brain and nerves, it is mostly re- 

 garded as a product of decomposition of their organic ingredients, rather 

 than as serving for the nutrition of the tissues. But from what sub- 

 stance it is derived, or in what way it is produced, is at present unknown. 

 It seems to be, without doubt, absorbed from the substance of the nervous 

 system by the blood, transported in this way to the liver, and thence 

 discharged with the bile into the alimentary canal. In the observations 

 of Flint,* its quantity in the blood of the dog was found to increase 

 while passing through the brain, from 0.52 to 1.09 per thousand parts. 

 Its presence in the blood, as a product of organic disintegration, would 

 explain its frequent occurrence in exudations and morbid deposits in 

 different parts of the body. According to most observers (Lehmann, 

 Gorup-Besanez, Hoppe-Seyler) it is a normal ingredient of the feces, 

 as well as of the sebaceous matter, and is therefore either wholly or 

 partly discharged from the body under its own form. 



* American Journal of the Medical Sciences. Philadelphia, October, 1862. 

 f Hoppe-Seyler. Physiologische Chemie. Berlin, 1877, p. 81. 



