182 



THE BILE. 



\ 



Fig. 50. 



suppression of the bile. These substances are, therefore, produced 

 in the glandular cells of the liver, by transformation of some other 

 of their ingredients. They are then exuded in a soluble form, as 

 part of the bile, and finally discharged by the excretory hepatic 

 ducts. 



The two substances described above as the tauro-cholate and 

 glyko-cholate of soda exist, properly speaking, only in the bile of 

 the ox, where they were first discovered by Strecker. In examin- 

 ing the biliary secretions of different species of animals, Strecker 

 found so great a resemblance between them, that he was disposed 

 to regard their ingredients as essentially the same. Having estab- 

 lished the existence in ox-bile of two peculiar substances, one 

 crystallizable and non-sulphurous (glyko-cholate), the other uncrys- 

 tallizable and sulphurous (tauro-cholate), he was led to consider 

 the bile in all species of animals as containing the same substances, 

 and as differing only in the relative quantity in which the two 

 were present. The only exception to this was 

 supposed to be pig's bile, in which Strecker found 

 a peculiar organic acid, the "hyo-cholic" or 

 " hyo-cholinic" acid, in combination with soda as 

 a base. 



The above conclusion of his, however, was not 

 entirely correct. It is true that the bile of all 

 animals, so far as examined, contains peculiar 

 substances, which resemble each other in being 

 freely soluble in water, soluble in absolute alco- 

 hol, and insoluble in ether ; and in giving also a 

 peculiar reaction with Pettenkofer's test, to be 

 described presently. But, at the same time, these 

 substances present certain minor differences in 

 different animals, which show them not to be 

 identical. 



In dog's bile, for example, there are, as in ox- 

 bile, two substances precipitable by ether from 

 their alcoholic solution; one crystallizable, the 

 other not so. But the former of these substances 

 crystallizes much more readily than the glyko- 

 cholate of soda from ox-bile. Dog's bile will not unfrequently begin 

 to crystallize freely in five to six hours after precipitation by ether 

 (Fig. 50) ; while in ox-bile it is usually twelve, and often twenty- 

 four or even forty-eight hours before crystallization is fully estab- 



Doo'sBiLE, extract- 

 ed with absolute alcoh ol 

 and precipitated with 

 ether. 



