* ANALYSES OF URINE OF DIFFERENT ANIMALS. 



Desirous of knowing by another experiment, whether the 

 urine of the beaver, like that of all other herbivorous animals, 

 • contained any muriate of ammonia, I put into a portion of the 



thickened liquor a bit of caustic potash ; and as no smell of 

 ammonia was perceived, even when heat was applied, I con* 

 eluded, that it contained no muriate of ammonia. But a phe- 

 nomenon presented itself, that occasioned me some surprise, 

 and made me desirous of discovering its cause. The liquor 

 coagulated into a gelatinous mass. Suspecting that this effect 

 was produced by the precipitation of some earthy substance, I 

 treated the whole of the thickened urine I had with caustic 

 potash j filtered off the liquor to obtain the matter in question j 

 and after it was washed and calcined, combined it with sul- 

 phuric acid, diluted with water, and obtained sulphate of mag- 

 nesia mixed with a little sulphate of lime. 

 , The acetate of Though I have said, that the urine of the beaver contains 



Tna^iieiia P* r " acetate of magnesia, yet I am not perfectly certain of it. It 

 haps a pro- . .,, ,,., . i i ■«« j . 



duct. is possible, that during the evaporation, though effected by a 



gentle heat, a certain quantity of acetic acid was formed ; and 

 that this acted on the carbonate of magnesia, remaining in the 

 liquor in consequence of its being more soluble than the car- 

 bonate of lime. 

 Colouring W e commonly find by the colour, smell, and taste of the 



juatter of its beaver's urine, and particularly by its property of dying 

 the urine. alumed stuffs, the kind of vegetable on which it h;is fed. 

 Instance. I" that in question I very evidently distinguished the colour- 



ing matter of willow bark, and its keeper afterward confirmed 

 my observation. 

 Properties of There are cases, theiefore, in which certain vegetable sub- 

 vegetables not stances are capable of passing the digestive organs and the cir- 

 stroyed in the dilation, without losing the properties that distinguish them ia 

 circulation. their natura l state . ^ 



Presence of * found also in the urine of the beaver a quantity of iron, 



iron, that at first astonished me: but on reflecting, that it had been 



saved in a tin vessel, and that it contained carbonic acid, I be- 

 lieve the greater part of the metal must be ascribed to this 

 vessel. 



The urine of the beaver, then, is composed of 



l,Urea, 

 Component 2 . A ■ j 



parts of the ' ' 



urine. 3, Ben* 



