GLYCOCHOLIC ACID. 227 



cholic acid or the conjugated biliary acids occur in the blood, 

 and whether these or choloidic acid occur in the intestine, we must 

 for the present leave these questions altogether undecided. 



Kunde, one of my pupils, has very distinctly recognised the pre- 

 sence of biliary matters by means of Pettenkofer's test in the fluid 

 from the hydrocele of an otherwise healthy man. By the same 

 test he was able to demonstrate the presence of biliary matters in the 

 blood of frogs, whose livers he had extirpated. (Of six frogs on 

 which he operated, only two survived.) 



Origin. We have already (see p. 126) attempted to show the 

 probability that cholic acid obtains its essential elements from the 

 fats, and that, in short, it is oleic acid conjugated with a non- 

 nitrogenous body. But in glycocholic acid we again meet with 

 the same nitrogenous adjunct which we have already encountered 

 in hippuric acid, and which, consequently, seems to be an ordinary 

 product of decomposition of nitrogenous bodies. We have already 

 remarked (see p. 197) that we are not in ac ondition to name the 

 proximate source of this adjunct, which is, however, isomeric with 

 fumar amide. 



This is not the most appropriate place for entering into the 

 physiological reasons for showing the part which the fat takes in 

 the formation of the principal constituents of the bile, or for 

 balancing the reasons for or against the formation of bile within the 

 hepatic cells. These are subjects pertaining to the second depart- 

 ment of our work, in which we shall consider the bile in general as 

 an animal secretion. We may, however, be permitted to remark 

 that the possibility of the primary formation of this acid in the 

 blood is indicated partly by the above-mentioned experiments of 

 Kunde, and partly by the not unfrequent occurrence of icterus 

 independently of any hepatic affection (Virchow), that is to say, 

 without infiltration of the parenchyma of the liver and of the 

 hepatic cells with bile- pigment. 



Uses. As we are not at present accurately acquainted with the 

 changes which glycocholic acid undergoes in the intestinal canal, 

 we are unable to state whether this acid exerts any special action 

 in the process of digestion. 



Q 2 



