838 METABOLISM. 



the first days of starvation. After the first few days of starvation the 

 elimination of nitrogen is more uniform. It may diminish gradually 

 and regularly until the death of the animals or there may be a rise in the 

 last days, a so-called premortal increase. Whether the one or the other 

 occurs depends upon the relation between the protein and fat content 

 of the body. 



Like the destruction of proteins during starvation, the decomposi- 

 tion of fat proceeds uninterruptedly, and the greatest part of the calories 

 needed during starvation are supplied by the fats. According to RUBNER 

 and VOIT the protein catabolism varies only slightly in starving animals 

 at rest and at an average temperature, and forms a constant portion 

 of the total exchange of energy; of the total calories in dogs 10-16 per 

 cent comes from the protein decomposition and 84-90 per cent from the 

 fats. This is at least true for starving animals which had a sufficiently 

 great original fat content. If on account of starvation the animal has 

 become relatively poorer in fat and the fat content of the body has fallen 

 below a certain limit, then in order to supply the calories necessary a 

 larger quantity of protein is destroyed and the premortal increase now 

 occurs (E. VOIT) . The reason for this premortal rise in protein catabol- 

 ism is still not completely understood (SCHULZ and collaborators l ). 



Since the fat has a diminishing influence on the destruction of pro- 

 teins corresponding to what was said above, the elimination of nitrogen 

 in starvation is less in fat than in lean individuals. For instance, only 

 9 grams of urea were voided in twenty-tour hours during the later stages 

 of starvation by a well-nourished and fat person suffering from disease 

 of the brain, while I. MUNK found that 20-29 grams urea were voided 

 daily by CETTi, 2 who had been poorly nourished. 



The investigations on the exchange of gas in starvation have shown, 

 as previously mentioned, that its absolute extent is diminished, 

 but that when the consumption of oxygen and elimination of carbon 

 dioxide are calculated on the unit weight of the body, 1 kilo, this 

 quantity quickly sinks to a minimum and then remains unchanged, or, on 

 the continuation of the starvation, may actually rise. It is a well- 

 known fact that the body temperature of starving animals remains almost 

 constant, without showing any appreciable decrease, during the greater 

 part of the starvation period. The temperature of the animal first sinks 

 a few days before death, which occurs at about 33-30 C. 



From what has been said about the respiratory quotient it follows 

 that in starvation it is about the same as with fat and meat exclusively 

 as food, i.e., approximately 0.7. This is often the case, but it may occa- 



1 Zeitschr. f. Biologie, 41, 167 and 502. See also Kaufmann, ibid., and-iV. Schulz, 

 ibid., and Pfluger's Arch., 76, with Mangold, Stiibel and Hempel, ibid., 114. 



2 Berl. kliii. Wochenschr., 1887. 



