152 PRODUCTION OF THE CHIEF 



liippuric acid are equal to the elements of clioleic 

 acid, plus a certain quantity of carbonic acid : 



2 at. hippuric acid, 2 (CigNHg O5 ) = CggNoHigOio 



5 at. starch 5 (C12 HioOjo) -= Qm H50O50 



2 at. oxygen = O^ 



The sum is = CggNoHgeOgo 



_ [ 2 at. choleic acid 2 (CssNH.^aOn) = C;6N2H66022 

 ^\20 at. carbonic acid 20 (C O, ) = C20 O40 



The sum is = CgeNiHgeOgz 



51. Now, since hippuric acid may be derived, 

 along with urea, from the compounds of proteine, 

 when to the elements of the latter are added those 

 of uric acid (see p. 151); since, further, uric acid, 

 choleic acid, and ammonia contain the elements of 

 proteine in a proportion almost identical with that 

 of proteine itself (see p. 136) ; it is obvious that, if 

 from 5 at. of proteine, with the addition of oxygen 

 and of the elements of water, there be removed the 

 elements of choleic acid and ammonia, the re- 

 mainder will represent the elements of hippuric 

 acid and of urea ; and that if, wdien this separation 

 occurs, and during the further transformation, the 

 elements of starch be present and enter into the 

 new products, we shall obtain an additional quantity 

 of choleic acid, as well as a certain amount of car- 

 bonic acid gas. 



That is to say — that if the elements of j)rotei7ie and 

 starch, oxygen and water being also present, undergo 

 transformation together and mutually affect each other ^ 

 we obtain, as the products of this metamorphosis, urea. 



