ON THE BALANCE OF THE VITAL ECONOMY. 



429 



72.927 kilogrammes. 



72.781 " 



rather a feeling of heaviness and weariness in the muscles, with nervous ex- 

 citation often rising to sleeplessness, which he attributes to the accumulation 

 in the blood of the alkaline salts of the meat. The following gives the result 

 by Ranke of an experiment on his own person in Pettenkofer's Respiration 

 apparatus when consuming as much pure flesh as possible : 



Initial weight, 

 Turmimil weight, 



Difference : a loss of weight of 140 grammes, notwithstanding the large amount 



of meat consumed. 



Esesta. N. C. 



86. 3 grammes of urea, . 40 28 17.26 



1.95 " of uric acid, 65 0.70 



99.0 " of feces, . 3.26 14.88 



In the respiration, ... 0. 231.20 

 2073 c. c. urine. 

 26.6 grammes of common salt. 



Ingesta. 



1832 grammes of meat, 

 70 " of fat, . 

 31 " of salts. 



3371 c c. of water. 



The difference in the amount of N = 18.1 grammes in favor of the ingesta, 

 shows that about 523 grammes of albumen were retained in the body, and 

 in order to cover the egesta about 23 grammes of fat must have been sup- 

 plied by the body. The result of the addition of fat to the food of a car- 

 nivorous animal was found byrBischoff and Voit materially to diminish the 

 disintegration of albuminous compounds, as shown by the diminished elimi- 

 nation of urea, so that only a third or fourth part is required. This is 

 intelligible enough when it is remembered that only a certain quantity of 

 ozonized oxygen is present at any moment in the body, and that since the 

 hydrocarbons possess a much higher affinity for oxygen than the albuminous 

 compounds, they essentially spare or prevent the disintegration and oxida- 

 tion of the latter. They do not, however, interfere with the ordinary de- 

 composition and reconstruction of the muscular tissues. But if, with the 

 fat, an increased proportion of meat be given, the proportion of urea also 

 increases, obviously because when much more albuminous material is con- 

 tained in the blood than is required for the maintenance of the tissues, and 

 especially of the muscles, it undergoes oxidation, and instead of being ap- 

 plied to the tissues is used up for the production of heat. Sugar and starch 

 consumed with a meat-diet seem to operate in precisely the same manner as 

 fat, except that their action, in combining with oxygen, and thus sparing 

 both the adipose and nitrogenous compounds, is in consequence of their 

 greater affinity for oxygen, still more marked than fat ; and if large quanti- 

 ties of sugar be given with sufficient albumen, a deposition of fat invariably 

 takes place. 



341. The differences which exist between Carnivora and Herbivora, in 

 regard to the mode in which the constituents of the Ingesta are distributed 

 through the excretions, are very striking. The first and most remarkable 

 feature of difference between them, is the very large proportion which the 

 fecal discharges of the Herbivora bear to the other excretions, which obvi- 

 ously proceeds from the iudigestibility of a large part of the alimentary 

 substances they consume. Of the water taken into the alimentary canal or 

 formed within the body, nearly two-thirds passes off with the fseces in the 

 Horse, whilst nearly the whole is absorbed in the Cat ; and of that which is 

 absorbed by the Horse, little more than one-seventh passes into the urine, 

 the remainder being exhaled from the lungs and skin ; whilst in the Cat, the 

 proportion which passes off by the skin is less than one-sixth of that which 

 is absorbed, the remainder being eliminated by the urine. Of the carbon 

 taken into the system, a relatively larger proportion passes off by the lungs 



