128 METAMORPHOSES OF BILE. 



must include the analytical expression of these modes 

 of decomposition ; in other words, that it must enable 

 us to show that the composition of the products derived 

 from it is related, in a clear and simple manner, to the 

 composition of the acid itself. This is the only satis- 

 factory test of a formula ; and the analytical expression 

 thus obtained, loses nothing of its truth or value, if it 

 should appear, as the researches of BERZELIUS seem 

 to show, that choleic and choloidic acids are mixtures 

 of different compounds ; for the relative proportions of 

 the elements cannot in any way be altered by this cir- 

 cumstance. 



25. In order to develope the metamorphoses which 

 choleic acid suffers under the influence of acids and 

 alkalies, the following formula alone can be adopted as 

 the empirical expression of the results of its analysis. 

 Formula of choleic acid : C 76 N 2 H 66 O 22 . (29) 



J repeat, that this formula may express the composi- 

 tion of one, or of two or more compounds ; no matter 

 of how many compounds the so-called choleic acid 

 may be made up, the above formula represents the rela- 

 tive proportions of all their elements taken together. 



If now we subtract from the elements of choleic acid, 

 the products formed by the action of muriatic acid, 

 namely, ammonia and taurine, we obtain the empirical 

 formula of choloidic acid. Thus ; from the 



Formula of choleic acid C 76 N 2 H 66 O 22 



subtract 

 1 atom taurine . . . C 4 NH 7 O 10 > r N H O 



1 -VTTT / == ^4 -^2** 10^10 



1 eq. ammonia . . . NH 3 $ 

 There remains the formula of cho- 

 loidic acid = C 72 H S6 O 12 (30) 



