URINE. 493 



II. The urine of the monkey, according to Coindet, has a 

 greenish-yellow colour, and its specific gravity varies from 1 -0045 

 to 1*0108. It contains a good deal of salts of sulphuric and 

 phosphoric acids, a great deal of salts of potash, but no uric acid.* 



III. The urine of the dog,f according to Tiedemann and Gme- 

 lin, has a yellowish or greenish-brown colour. It has an acid 

 reaction ; becomes reddish-yellow, and then green when mixed 

 with muriatic acid. When mixed with nitric acid, much uric 

 acid fell, and the urine became green, then blue, and finally 

 dark-red.J These phenomena show clearly that the urine of the 

 dog examined contained bile. 



IV. The urine of the horse has usually an amber colour. 

 When voided it is sometimes transparent, sometimes muddy, and 

 it soon deposits a white precipitate, consisting chiefly of carbo- 

 nate of lime. Its specific gravity, according to Fourcroy and 

 Vauquelin, varies from 1*03 to 1*05. The specific gravity of a 

 specimen examined by Dr Prout was 1-0293. That of a horse 

 experimented on by Boussingault, 1*064.|| The average quan- 

 tity voided in twenty-four hours was only 2-928 Ibs. He found 

 in it a greater quantity of urea than in human urine. It was 

 announced many years ago by Fourcroy and Vauquelin, that the 

 urine of the horse contains benzoic acid. But Liebig has shown 

 that the acid contained in the urine of the horse is not the ben- 

 zoic, but another acid containing peculiar properties, to which he 

 has given the name of hippuric^ and which has been described 

 in a former part of this work.** 



The constituents of the urine of the horse, as determined by 

 Fourcroy and Vauquelin, are the following : 



Water and mucus, . 94' 



Carbonate of lime, . !! 



Carbonate of soda, . 0*9 



Hippurate of soda, . 2 -4 



Chloride of potassium, . 0-9 



Urea, . . 0-7 



lOO-Oft 



* Biblioth. Univer. xxx. 492. f The gall -ducts of this animal were tied. 



\ On Digestion, ii. 4. Annals of Philosophy, xvi. 150. 



|| Ann. de Chim. et de Phys. Ixxi. 128. f Ibid, xliii. 188. 



* See Chemistry of Vegetables, p. 46. ft Mem. de Hnstitut, ii. 431. 



