530 A MANUAL OF PHYSIOLOGY 



income.* In both cases we say that the body is in nitrogenous 

 equilibrium. 



A starving animal or a fever patient, on the other hand, is 

 living upon capital, the former entirely, the latter in part ; the 

 expenditure of nitrogen is greater than the income. A growing 

 child is living below its income, is increasing its capital of flesh. 

 In neither case is nitrogenous equilibrium present. 



The starving|animal, as long as life lasts, excretes kreatinin, 

 urea and other nitrogenous substances, and gives off carbon 

 dioxide ; but its expenditure, and especially its expenditure of 

 nitrogen, is pitched upon the lowest scale. It lives penuriously, 

 it spins out its resources ; its glycogen goes, its fat goes, a certain 



FIG. 184. DIAGRAM SHOWING Loss OF WEIGHT OF THE ORGANS IN 

 STARVATION. 



The numbers under I. are the percentages of the total loss of body-weight 

 borne by the various organs and tissues. The numbers under II. give the 

 percentage loss of weight of each organ calculated on its original weight as 

 indicated by comparison with the organs of a similar animal killed in good 

 condition. 



part of its protein goes, and when its weight has fallen from 25 to 

 50 per cent., it dies. At death the heart and central nervous 

 system are found to have scarcely lost in weight ; the other organs 

 have been sacrificed to feed them. Fig. 184 shows the percentage 

 loss of weight and the proportion of the total loss which falls upon 

 each of the organs of a cat in starvation (Voit). 



For the first day of starvation the excretion of urea in a dog 

 or cat is not diminished ; it takes about twenty-four hours for 



* For long experiments extending over many days the nitrogen balance 

 may be considered as practically the same as the protein balance, but this 

 is not necessarily true of short periods of time, since the stock of nitrogen 

 present in the body in other forms than proteins, although relatively 

 small, is subject to variations. 



