OF ANIMALS. 457 



and soda salts. Braconnot also found in calves' urine an organic 

 matter which was soluble in alcohol, precipitable by tannic acid, 

 dissolved on boiling, but again separated on cooling. Lastly, this 

 secretion does not contain even 1-g- of solid constituents; according 

 to Braconnot,, they amount to 0'62$. 



The allantoic fluid of the foetal calf has, as yet, only been care- 

 fully analysed by Lassaigne ;* from his observations, it seems to 

 possess precisely the same properties and the same composition 

 as the urine of the calf, while still living on milk. 



We have already mentioned that the urine of rabbits, as w el 

 probably, as that of other herbivorous animals, becomes acid, and 

 assumes almost all the properties of the urine of the carnivora, 

 when these creatures have been kept fasting for a long time, 

 or have been compelled to digest animal food. 



Hyraceum appears, from Reichel's analysis, to be at all events 

 very much mixed with the urine of the animal (Hyrax capensis) : 

 but from a microscopical and chemical examination, to which I 

 exposed a specimen of this substance, whose therapeutic value was 

 to be tested, I convinced myself that it consists solely of the 

 solid excrement of this creature; I found in it the remains of 

 plants and vegetable fibres, together with isolated prosenchyma 

 cells and spiral vessels, which rendered it more than probable that 

 the vegetable matters had passed through the intestine, and were 

 not either accidentally or intentionally superadded after its dis- 

 charge; it was only on the outer surface that fragments of the 

 skeletons of insects could be detected, stamped, as it were, 

 upon it : in addition to a very large amount of resinous matters 

 and carbolic acid, this mass undoubtedly contained biliary 

 matters ; but no urea, or uric, or hippuric acid could be discovered. 



The urine of birds, which for the most part forms a whitish 

 investment to the solid excrements of these animals, consists 

 essentially of urates, and especially of the bi-urates of ammonia 

 and lime ; Coindet maintains that he has found urea in birds' 

 urine. 



The urine of serpents, which is often discharged independently 

 of the solid excrement, is at first pulpy, but soon becomes solid 

 and dry; it consists for the most part of alkaline bi-urates, 

 a little urea, and earthy phosphates. 



The urine of frogs is fluid ; it contains urea, chloride of 

 sodium, and a little phosphate of lime. 



* Ann. do Cliim. ct de Phys. 1 Scr. T. 17, p. 301. 



