SECRETIONS AND EXCRETIONS. 4& 



teme, with the addition of the elements of i give rise to the production of hippuric acid 

 3 at. of uric acid and 2 at. of oxygen, might I and urea. 



2 at. proteine, 2 (CWH^O 14 ) = 



3 at. uric acid, 3 (C 10 N 4 H 4 O 6 ) = 



2 at. oxygen = O 2 



The sum is ... = 



6 at. hippuric acid, 6 (C 18 N H 8 O 5 ) = C 108 N 6 H 48 O 30 



9 at- urea . . . 9 (C 2 N 2 H 4 2 ) = C 18 N 18 H 36 18 



The sum is = 



50. Finally, if we bear in mind, that, in 

 the herbivora, the non-nitrogenized con- 

 stituents of their food (starch, &c.) must, as 

 we have shown, play an essential part in 

 the formation of the bile; that to their ele- 

 ments must of necessity be added those of 

 a nilrogenized compound, in order to pro- 



duce the nitrogenized constituents of the 

 bile, the most striking result of the combina- 

 tions thus suggested is this, that the elements 

 of starch added to those of hippuric acid are 

 equal to the elements of choleic acid, 

 a certain quantity of carbonic acid : 



2 at. hippuric acid, 2 (C 18 NH 8 O 5 ) C 36 N 2 H 16 O 10 

 5 at. starch . . 5 (C 12 H 10 O 10 ) = C 60 H^O 50 

 2 at. oxygen . . ___ == _ O 2 



The sum is . . . . . 

 2 at. choleic acid 2 (C^NH^O 11 ) 

 20 at. carbonic acid 20 (C O 2 ) = C 20 



O 40 



The sum is 



51. Now since hippuric acid may be de- 

 rived, along with urea, from the compounds 

 of proteine, when to the. elements of the 

 latter are added those of uric acid (see p. 

 49;) since, further, uric acid, choleic acid, 

 and ammonia contain the elements of pro- 

 teine in a proportion almost identical with 

 that of proteine itself (see p. 44;) it is 

 obvious that, if from 5 at. of proteine, with 

 the addition of oxygen and of the elements 

 Oi" water, there be removed the elements of 

 choleic acid and ammonia, the remainder 

 will represent the elements of hippuric acid 

 and of urea ; and that if, when this separa- 



5 at. proteine "I 

 15 at. starch I _ 



12 at. water 

 5 at. oxygen J 

 In detail 



5 at. proteine, 5 (C^H^O 14 ) = 

 15 at. starch, 15 (C 12 H 10 O 10 ) C 180 

 12 at\ water, 12 ( HO ) 



5 at. oxygen = 



tion occurs, and during the further transfor- 

 mation, 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 carbonic 

 acid gas. 



That is to say that if the elements of 

 proteine and starch, oxygen and water being 

 also present, undergo transformation together 

 and mutually affect each other, we obtain, 

 as the product of this metamorphosis, urea, 

 choleic acid, ammonia, and carbonic acid, 

 and besides these, no other product whatever. 



The elements of 



f9 at. choleic acid 

 9 at. urea 

 3 at. ammonia 

 60 at. carbonic acid 



H 150 O 150 

 H 12 O 12 

 O 5 



The sum is . . . . = C 420 N 30 H 342 O 23>r 



and 



9 at. choleic acid, 

 9 at. urea, . . 

 3 at. ammonia, 



60 at. carbonic acid, 60 (C 



C^NH^O 11 ) = 

 C*N 2 H 4 O 2 > = CWH 38 O 18 

 N H 3 ) = N 3 H 9 



O 2 ) = C 60 



O 120 



The sum is 



The transformation of the compounds of 

 pioteme present in the body is effected by 

 means of the oxygen conveyed by the arte- 

 rial blood, and if the elements of starch, 

 rendered soluble in the stomach, and thus 

 carried to every part, enter into the newly 

 formed compounds, we have the chief con- 

 stituents of the animal secretions and ex- 

 cretions ; carbonic acid, the excretion of the 

 lungs, urea and carbonate of ammonia, ex- 

 7 



creted by the kidneys, and choleic acid, se- 

 creted by the liver. 



Nothing, therefore, in the chemical com- 

 position of those matters which may be 

 supposed to take a share in these metamor- 

 phoses, is opposed to the supposition that a 

 part of the carbon of the non azotized food 

 enters into the composition of the bile. 



52. Pat, in the animal body, disappears 

 when the supply of oxygen is abundant. 

 E 



