FINAL PRODUCTS. 425 



exactly the same as in feeding with fat meat s and hence, for the 

 sake of brevity, we shall omit all further details. 



If we pause for a moment in our consideration of the excretion 

 of the elements, we shall find the most decisive confirmation, in 

 two interesting series of experiments by Schmidt, of the proposi- 

 tion first enounced by Liebig, that the bile is not only resorbed in 

 the intestine, but is also consumed, and for the most part separated 

 through the lungs. Thus, for instance, we find from the statistical 

 observations made by Schmidt on two dogs, having biliary fistulee, 

 that whether the animals had had a very abundant or only a scanty 

 flesh-diet, from lOg to 12% of the absorbed carbon, and from 11 ta 

 13 o of the absorbed hydrogen were excreted by the bile, and that 

 this loss was not uniformly distributed through the excretions, but 

 was exclusively limited to the products of respiration. Only 3J 

 or S'2% of the absorbed nitrogen passes into the bile, and this 

 is as nearly as possible the quantity which is missing from the 

 urine. 



We regret that we are compelled to deviate from our general 

 rule in respect to this comprehensive inquiry, by omitting to con- 

 firm by numerical data the facts and conclusions that have been 

 advanced ; but had we done otherwise we should have been obliged 

 to transcribe the whole of Schmidt's observations, as he has merely 

 given the most necessary empirical results. We must, therefore, 

 content ourselves with giving the most important conclusions 

 deduced from his inquiries, more especially as many points refer- 

 ring to the individual factors of the metamorphosis of matter 

 would have been introduced in the proper place, had we been 

 earlier acquainted with the special details of these admirable 

 labours. 



We learn from the experiments on cats, that for 1 000 grammes' 

 weight of these animals there are required in the twenty-four hours 

 at least as much as 44'118 grammes of flesh to maintain the original 

 bodily weight, and that in addition to this, 18'632 grammes of oxygen 

 must be absorbed in order to apply this nutrient matter to the 

 wants of the organism ; and, consequently, that the minimum of 

 food for the carnivorous animals experimented-upon averages, 

 according to this observation about l-23rd, and the necessary 

 oxygen about 1-5 5th of the whole weight of the body. On the 

 other hand, when the animals are kept without food, only 22' 118 

 grammes are lost in the course of twenty-four hours from the whole 

 weight of the body by the excretions (between the third and the 

 ninth day), to the metamorphosis of which 15*749 grammes of 



V 



