METABOLISM, NUTRITION AND DIETETICS 461 



In both cases we say that the body is in nitrogenous equi- 

 librium. 



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 urea and 

 gives off carbon dioxide ; but its expenditure, and especially 



FIG. 135. 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. 



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 part of its proteid 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. 135 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 



