COMPOSITION OF THE BILE. 403 



two salts were discovered in the bile of the ox, by Strecker, in 1848. Sodi- 

 um glycocholate exists in quantity in ox-gall. Both of these salts may be 

 precipitated from an alcoholic extract of bile by an excess of ether. The 

 taurocholate is precipitated in the form of dark, resinous drops which crys- 

 tallize with difficulty. The glycocholate is readily crystallizable. The bil- 

 iary salts are very soluble in water and in alcohol. Their reaction is neutral. 



There can be no doubt that the biliary salts are products of secretion and 

 are formed in the substance of the liver. In no instance have they ever 

 been discovered in the blood in health ; and although they present certain 

 points of resemblance with some of the constituents of the urine, they have 

 never been found in the excreta. In experiments made by Miiller, Kunde, 

 Lehmann and Moleschott, on frogs, in which the liver was removed and 

 the animal survived several days and in the observations of Moleschott, be- 

 tween two and three weeks it was found impossible to determine the pres- 

 ence of the biliary salts in the blood. There is no reason, therefore, for sup- 

 posing that these salts are products of disassimilation. Once discharged 

 into the intestine, they undergo certain changes and can no longer be recog- 

 nized by the usual tests ; but experiments have shown that, changed or un- 

 changed, they are absorbed with the products of digestion. They are prob- 

 ably concerned in the digestive action of the bile. 



Cholesterine. Cholesterine (C^H^O) is a normal constituent of various 

 of the tissues and fluids of the body. Most authors state that it is found in 

 the bile, blood, liver, nervous tissue, crystalline lens, meconium and faecal 

 matter. It is to be found in all these situations, with the exception of the 

 faeces, where it does not exist normally, being transformed into stercorine in 

 its passage down the intestinal canal. 



In the fluids of the body cholesterine exists in solution ; but by virtue of 

 what constituents it is held in this condition, is a question that is not en- 

 tirely settled. It is stated that the biliary salts have the power of holding 

 cholesterine in solution in the bile, and that the small quantity of fatty acids 

 contained in the blood holds it in solution in that fluid ; but direct experi- 

 ments on this point are wanting. In the nervous tissue and in the crys- 

 talline lens, it is united with the other substances which go to make up 

 these parts. After it is discharged into the intestinal canal, when it is not 

 changed into stercorine it is to be found in a crystalline form, as in the 

 meconium, and in the faeces of certain animals in a state of hibernation. In 

 pathological fluids and in tumors, it is found in a crystalline form and may 

 be detected by microscopical examination. 



Cholesterine is usually described as an alcohol, having many of the prop- 

 erties of the fats, but not that of saponification with the alkalies. It is neu- 

 tral, inodorous, crystallizable, insoluble in water, soluble in ether and very 

 soluble in hot alcohol, though sparingly soluble in cold alcohol. It is in- 

 flammable and burns with a bright flame. It is not attacked by the alkalies 

 even after prolonged boiling. When treated with strong sulphuric acid it 

 strikes a peculiar red color. 



Cholesterine may easily and certainly be recognized under the microscope 



