METABOLISM DURING INANITION. 889 
the fact that there is still plenty of non-nitrogenous material (fat) able 
to be drawn upon. The sudden increase which is sometimes met with 
after a prolonged period of starvation is due no doubt to the fact that 
by this time the non-proteid materials of the body, which have been 
up to that time used for the production of energy by their oxidation, 
are now practically exhausted, and the whole energy and heat of the 
body must necessarily be derived from the tissues themselves ; since 
these are composed essentially of proteid, there is a considerable rise 
of proteid metabolism. 
The earl tun dioxide exhaled from the lungs during starvation con- 
tinues to be given off in proportion to the weight of the body, to the 
work done, and in inverse proportion to the temperature of the environ- 
ment. In a man weighing 71 kilos., Pettenkofer and Voit found that 
during the first day of fasting 201*3 grms. C were given off 1 by the respir- 
ation, and 5'8 grms. by the urine, in which also 12*5 grms. N was elimin- 
ated. This corresponded to a loss of 78 grms. proteid (370 grms. flesh) 
and 215 grms. fat. The same man was found by Pettenkofer and Voit 
to lose, when working on the first day of fasting, 75 grms. proteid (478 
grins, flesh) and 380 grms. fat. The amount of oxygen taken in in the 
two cases was 760 and 1072 grms. respectively, and the amount of water 
exhaled 889 and 1777 grms. Eanke found on the second day of fasting, 
in a fat subject weighing about 70 kilos., 8 grms. N and 3*7 grms. C in 
the urine, and 180-9 grms. C given off by the lungs ; corresponding to 
50 grms. proteid (235 grms. flesh) and 204 grms. fat. 
For a considerable time, as a result of the oxidation of fat and body 
proteid, the temperature of a fasting animal is maintained to about its 
normal amount. Towards the end, however, of starvation, the temperature 
begins to sink, and finally rapidly falls, the meaning of this being that 
the animal has now practically exhausted all the nutriment which it 
can take from the tissues, and that the amount of oxidation has become 
reduced, so that the temperature is no longer capable of being main- 
tained at normal. The change is also, in part, doubtless due to the 
fact that the heat regulating functions of the nervous system are 
beginning to break down in consequence of the deficiency of nutriment. 
It has been suggested that an animal dying of starvation practically 
dies of cold ; and it is undoubtedly true that the life of a starved animal 
can be prolonged considerably by the employment of artificial warmth, 
since this diminishes the amount of oxidation necessary for maintaining 
the animal heat, and thus economises the energy -producing substances 
within the body ; but it is, of course, not possible for the artificial 
warming of an animal to prolong life to any great extent under 
circumstances of complete deprivation of food. 
Numerous experiments have been made to determine the amount of 
loss of the several organs and tissues of the body which have occurred 
during starvation, and also the relative composition of such tissues and 
organs as compared with those of a well-nourished animal. All such 
experiments tend to show that the most essential organs of the body, 
such as the heart and nervous system, live during a period of starvation 
at the expense of the other tissues. 1 
1 Bidder and Schmidt, " Verdauungssafte u. Stoffwechsel," 1852; Bisehoff and Voit, 
"Die Gesetze der Ernahrung des Fleisehfressers,'' 1S60 ; Pettenkofer and Voit, Ztschr. 
f. Biol., Miinchen, Bde. ii. and v. ; J. Eanke, " Die Ernahrung des Meiischen," 1876 ; Voit, 
"Ernahrung," Hermann's "Handbuch," 1881, Bd. vi. 
