18 Comparative Analysis of the Urine of various Animals. 



Second cliflTcrcnce : thev do not contain anv uric acid, 

 nor any combination of this acid with the alkalis. At least, 

 there was no sensible trace when the experiment was lour 

 times repeated. 



The defect of uric acid in these urines was the more re- 

 markable, as I used to ascribe its formation to aiiimal food, 

 'i'hc third dilVereiice exhibited by the urine of tlie lion 

 and the royal tiger from ikat of man, was the almost total 

 absence ol phosphate of lime. 



This is what might be naturally expected, since this salt 

 cannot be dissolved in water except by means of a super- 

 abundance of acid, and the urine in question is on the 

 contrary alkaline. 



It would nevertheless seem that the kidneys of these 

 animals sepnrate a, certnin quantity of this salt from the 

 blond; fori found slight traces of it in these urines; 

 and ammonia is formed in the bladder only, where pro- 

 bably it precij)itates phosphate of lime: and this is without 

 doubt the reason that the urine of these animals issues 

 from the bladder almost always in a turbid state. 



If according to this we ever find calculi in the bladders 

 of these animals, they can he formed of phosphate of lime 

 only, since this is the only insoluble substance they contain. 

 Fourth difference : the urines of the lion and the liger 

 contain but an infinitely small quantity of muriate of soda^ 

 wherea" that of men generally exhibits a great deal, 



\Vc find in these urines a great cjuantity of urea very 

 much disposed to crystallization, and in general a little co- 

 loured ; phosjihates of soda and ammonia, sulphate of 

 potash, a mucous matter, and a trace of iron. 



'I'he al)ove are the point.-; in which the urines of the lion 



and roval tiger rcsendile that of man ; but they differ, as has 



been shown, in a suflicient number of points lo warrant us 



in I'orming a particular species. It is composed as follows: 



1. Urea. 



'2. Aninud nuicus. 

 3. Phosphate of soda. 

 •1. Piujsnhate of annnonia. 

 .'). Muriate of anmnonia. 

 ('). A irace of phosphaic of lime. 

 7, Suljihate of potasli in a large quantity, 

 fct. An atom of muriate of soda. 



Uilne of the Beaver. 



A careful aualyiis several limes repeated of the urine of 



the 



