LIQUID PARTS OF ANIMALS. 



well dried amounts to one-eighth or one-ninth of the original 

 quantity of bile. 



Ox-bile has been long used as a substitute for soap to remove 

 stains from carpets, woollen cloths, &c. On that account it was 

 considered by the iatro-chemists as a soap or a compound of an 

 animal oil and an alkali. The alkali was ascertained to be soda; 

 and this soda was, of course, united to an oily acid, which con- 

 verted it into soap. This view was considered as overturned by 

 the experiments of Thenard. Berzelius's analysis was not incoin - 

 patible with the soapy nature of bile ; though he does not appear 

 to have considered the liquid in that point of view. 



It was shown by M. Demarcay in 1838 that the old opinion 

 of the soapy nature of bile, supported by Cadet, is, after all that 

 has been said to the contrary, the true one. He has proved that 

 the essential constituents of bile are soda, and an oily acid com- 

 bined with the soda, which he has distinguished by the name of 

 choleic acidy* and of which an account has been given in a pre- 

 vious part of this volume.f 



We possesss but little information respecting the bile of birds. 

 Tiedemann and Gmelin found it very different in different species, 

 and even in those of the same species. Sometimes it was greenish- 

 blue, sometimes emerald green, and sometimes verdigris green. 

 In fowls and ducks it was so glutinous, that it could be drawn 

 into long threads, and it contained mucous clots. They even 

 made an analysis of the bile of a duck. They found the salts 

 the same as in ox-bile ; and it is probable, from their experi- 

 ments, that it consists essentially of choleate of soda, though no 

 experiments are stated from which the properties of the choleic 

 acid can be determined. J 



According to Tiedemann and Gmelin, the bile contained in 

 the gall-bladder of the Rana temporaria amounted to only a few 

 drops. It was yellowish-green, transparent, and very liquid. Its 

 taste was sweetish and much less bitter than the bile of fishes. 

 When mixed with solution of potash, it becomes muddy, and 

 yellow flocks precipitate. 



* Ann. de Chim. et de Phys. Ixvii. 177. 



f It is not unlikely that, besides choleic acid, bile may contain some other oily 

 acid. At least, Dema^ay made no attempt to determine whether some other 

 acid was not present. 



| Recheiches sur la Digestion, ii. 158. 



