SECRETIONS AND EXCRETIONS. 153 



choleic acid, ammonia, and carbonic acid, and besides 

 these, no other product whatever. 

 The elements of 



5 at. proteine "J f 9 at. choleic acid 

 15 at. starch | I 9 at. urea 

 12 at. water | j 3 at. ammonia 

 5 at. oxygen J [60 at. carbonic acid 

 In detail 



5 at. proteine, 5 (C^H^Ou) = 

 15 at. starch, 15 (Ci 2 Hi O w ) = 

 12 at. water, 12 ( HO ) = H 12 O 12 



5 at. oxygen O 5 



The sum is .................. = C 420 N 30 H34 2 O 237 



and 



9 at. choleic acid, 9 (C^N H^On) = C^Ng H^Og., 

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



3 at. ammonia, ... 3 ( N H 3 )= N 3 H 9 

 60 at. carbonic acid, 60 (C O 2 ) = C w O 120 



The sum is 



The transformation of the compounds of proteine 

 present in the body is effected by means of the 

 oxygen conveyed by the arterial 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 constituents 

 of the animal secretions and excretions ; carbonic 

 acid, the excretion of the lungs, urea and carbonate 

 of ammonia, excreted by the kidneys, and choleic 

 acid, secreted by the liver. 



Nothing, therefore, in the chemical composition 

 of those matters which may be supposed to take a 



