424 NUTRITION. 



average, only half of the water which entered the intestine was 

 absorbed, but in the carnivora, as was shown by Schmidt's other 

 experiments, the quantity amounted only to !--, or at most 4-. If 

 we disregard the quantities of the other elements which remain in 

 the intestine, we find that in the herbivora, a very small portion, 

 from 15- to 20g only of the water, which is either absorbed or 

 formed, is eliminated through the kidneys, whilst in the herbivora 

 as much as 4-5ths of the absorbed water passes into the urine. The 

 fact that the absorbed carbon is excreted in far larger quantities 

 through the lungs in the herbivora than the carnivora (the 

 relation of the carbon in the urine being as 1 : 19 in the former, 

 and as 1 : 9'5 in the latter) possibly depends solely upon the 

 nature of the food, and not upon any special relations of the 

 organism; for the non-nitrogenous matters become almost com- 

 pletely decomposed into carbonic acid and water, and hence they 

 yield absolutely nothing, or only a very small amount to the urine, 

 whilst the products of decomposition which are produced from the 

 albuminafes yield their nitrogen to the urine, although always in 

 combination with certain quantities of carbon. We thus obtain a 

 kind of check for our calculations of the urine and respiration. In 

 the same manner we find in reference to the hydrogen that relatively 

 much less is eliminated through the kidneys in the herbivora than in 

 the carnivora. (The ratio of the hydrogen excreted through the urine 

 is to that eliminated through the lungs as 1 : 23*0 in the herbivora, 

 and as 1 : 3'3 in the carnivora.) The case differs in respect to the 

 nitrogen ; for the herbivora frequently excrete by perspiration as 

 much as 40 of the nitrogen they had absorbed, whilst the carni- 

 vora scarcely eliminate as much as Ig. Earlier investigations 

 have taught us that the urine of the herbivora is poorer in nitrogen 

 and in urea, the substance in which it is carried off, than that of 

 the carnivora, which (as Schmidt has also observed) is very often 

 scarcely anything more than a saline solution of urea. It would, 

 therefore, almost appear as if the process, of oxidation were so 

 far more abundant in the herbivora than the carnivora, that in the 

 organism of the former the albuminates were decomposed even 

 beyond what was necessary for the formatiom of urea ; and on this 

 account, the urine of the herbivora is entirely deficient in the earlier 

 product of the disintegration of the albuminates, namely, uric 

 acid. 



When the metamorphosis of matter is effected in the organism 

 without any compensation from without, the proportions of the 

 elements of the urine to those of the perspiration are almost 



