342 



THE SECRETIONS: 



Urine of Animals. 



The chemistry of the urine of animals is still in a very defi- 

 cient state. I shall here give the little that is known on the 

 subject. 



The urine of carnivorous animals is, at the period of its dis- 

 charge, acid, but speedily becomes alkaline, in consequence of 

 the formation of ammonia. This observation of Hieronymi's 

 is confirmed by Hiinefeld, who found that the urine of the bear 

 retained its acid reaction for a considerable period. Vauquelin 

 found a large proportion of urea, but no uric acid in the urine 

 of beasts of prey. Hiinefeld also missed the uric acid, but it 

 was detected by Hieronymi. Hieronymi carefully analysed 

 the urine of the lion, the tiger, and the leopard, and its compo- 

 sition appeared much the same in these three animals. The spe- 

 cific gravity of the urine of each animal varied between 1059 

 and 1076. It was clear, of a bright yellow colour, had a 

 pungent disagreeable odour, an acid reaction, and a nauseous 

 bitter taste ; after standing for a short time, it became alkaline. 

 On collecting and evaporating the urine, there was a coagula- 

 tion of some white flocculent matter ; and as the concentration 

 increased, the greater part of the urea began to separate in a 

 crystalline form. The mixed urine of these three animals gave 

 the following result : 



Water . . . . 846-00 



Solid constituents . . . 154-00 



Urea, alcohol-extract, and free lactic acid 132-20 



Uric acid . . . 0-22 



Vesical mucus . . 5-10 



Sulphate of potash . 1-22 

 Chloride of ammonium, and a little chloride of sodium 1-16 



Earthy phosphates . . 1-76 



Phosphates of soda and potash 8-02 



Phosphate of ammonia . 1'02 



Lactate of potash . . 3-30 



The urine of herbivorous animals likewise contains a large 

 quantity of urea, but no uric acid, 1 there being in its place hip- 

 puric acid. The urine of the horse was analysed by Fourcroy 

 and Vauquelin : they describe it as of a yellow colour, often 



1 [Traces of uric acid have been occasionally detected by Fo wnes and other chemists' 

 in the urine of the graminivora. See Vol. I, p. 53.] 



