54 NUTRITION OF CARNIVORA. 



with beef, when taken out of the rectum, consisted, 

 according to L. Gmelin and Tiedemann, of urate of 

 ammonia. In like manner, the faeces in lions and tigers 

 are scanty and dry, consisting chiefly of bone earth, 

 with mere traces of compounds containing carbon ; but 

 their urine contains, not urate of ammonia, but urea, a 

 compound in which carbon and nitrogen are to each 

 other in the same ratio as in neutral carbonate of am- 

 monia. 



Assuming that their food (flesh, &c.) contains car- 

 bon and nitrogen in the ratio of eight equivalents to one, 

 we find these elements in their urine in the ratio of 

 one equivalent to one ; a smaller proportion of carbon, 

 therefore, than in serpents, in which respiration is so 

 much less active. 



The whole of the carbon and hydrogen which the 

 food of these animals contained, beyond the amount 

 which we find in their excrements, has disappeared, in 

 the process of respiration, as carbonic acid and water. 



Had the animal food been burned in a furnace, the 

 change produced in it would only have differed in the 

 form of combination assumed by the nitrogen from that 

 which it underwent in the body of the animal. The 

 nitrogen would have appeared, with part of the carbon 

 and hydrogen, as carbonate of ammonia, while the rest 

 of the carbon and hydrogen would have formed car- 

 bonic acid and water. The incombustible parts would 

 have taken the form of ashes, and any part of the car- 

 bon unconsumed from a deficiency of oxygen, would 

 have appeared as soot, or lampblack. Now the solid 



