588 

 C 



GENERAL METABOLISM 



[CH. XXXIX. 



= 14'5. In carnivorous animals, which, according to Bidder 



C 

 and Schmidt, use 14 N and 6'2 C per kilo, per diem, -^ = 4 -4. 



Q 



In the human being on a flesh diet -^ = 5*2 ; the exchange thus 



approaches the condition of the carnivora. This is illustrated by 

 the following balance-sheet (Ranke) : 



The details of the above experiment may be given as illustrating 

 the method of working out a problem in exchange of material : 1832 

 grammes of meat used as food yielded 3*4 per cent, of nitrogen, i.e. 

 62'3 gr., and 12'5 per cent, of carbon, i.e. 229'3 gr. ; 70 gr. of fat 

 added to the food yielded 72 per cent, of carbon, i.e. 50 '3 gr. : 

 229'3 + 50 t 3 = 279'6 = total carbon in food. During the same period 

 86'3 gr. of urea were discharged, containing 46*6 per cent., i.e. 40'4 

 gr. of nitrogen, and 20 per cent., i.e. 17*3 gr. of carbon, to which must 

 be added 2 gr. of uric acid, containing 33 per cent., i.e. 0'66 gr. of 

 nitrogen, and 35 per cent., i.e. 0'7 gr. of carbon. Further, 2'9 gr. of 

 nitrogen and 14 gr. of carbon were discharged in the faeces, and 231 

 gr. of carbon as carbonic acid in the expired air. Hence the total 

 discharge of nitrogen = 40 '4 + 0*66 + 2*9 = 44 gr., and the total dis- 

 charge of carbon = 17'3 + 07 + 14 + 231 = 263 gr. Deducting the 

 quantity of nitrogen discharged from that taken in, 18 '3 gr. must 

 have been retained in the body, as 108 gr. of proteid, and consequently 

 53 per cent, of that weight =62'5 gr. of carbon, were also retained. 

 Comparing the quantity of carbon disposed of in the twenty-four 

 hours with the quantity introduced as food, we find the former is in 

 excess by 45 '9 gr., which must have been derived from the disinte- 

 gration of the fat of the body. 



Another table of exchange of material on adequate diet may be 

 quoted from the work of Pettenkofer and Voit. This takes into 

 account the elimination of water as well as of carbon and nitrogen. 

 In the first experiment the man did no work. 



