CASEINE IDENTICAL. 53 



the flesh, the blood, the brain, and nerves, in short, 

 every thing, has disappeared. 



The only excrement, strictly speaking, is a substance 

 expelled by the urinary passage. When dry, it is pure 

 white, like chalk ; it contains much nitrogen, and a 

 small quantity of carbonate and phosphate of lime 

 mixed with the mass. 



This excrement is urate of ammonia, a chemical 

 compound, in which the nitrogen bears* to the carbon 

 the same proportion as in bicarbonate of ammonia. 

 For every equivalent of nitrogen it contains two equiv- 

 alents of carbon. 



But muscular fibre, blood, membranes, and skin, con- 

 tain four times as much carbon for the same amount of 

 nitrogen, or eight equivalents to one ; and if we add to 

 this the carbon of the fat and nervous substance, it is 

 obvious that the serpent has consumed, for every equiv- 

 alent of nitrogen, much more than eight equivalents of 

 carbon. 



If now we assume, that the urate of ammonia contains 

 all the nitrogen of the animal consumed, then at least 

 six equivalents of carbon, which were in combination 

 with this nitrogen, must have been given out in a differ- 

 ent form from the two equivalents which are found in 

 the urate of ammonia. 



Now we know, with perfect certainty, that this car- 

 bon has been given out through the skin and lungs, 

 which could only take place in the form of an oxidized 

 product. 



The excrements of a buzzard which had been fed 

 5* 



