920 METABOLISM. 



individuality and the race of the animal are of importance for flesh deposi- 

 tion. 



The conditions in young, growing individuals differ from those in 

 adults. In the first the protein is necessary for the building up of the 

 growing tissue and in them an abundant true flesh deposition takes place. 

 For this protein fattening the amount of supply does not take first place, 

 but rather the energy of development. 



As above stated (Chapter IX), in regard to the formation of fat in the 

 animal body, the most essential condition for a fat deposition is an over- 

 feeding with non-nitrogenous foods. The extent of fat deposition is 

 determined by the excess of calories administered over those actually 

 needed. But as protein and fat are expensive nutritive bodies as com- 

 pared with carbohydrates, the supply of greater quantities of carbo- 

 hydrates is important for fat deposition. The body decomposes less 

 substances at rest than during activity. Bodily rest, besides a proper 

 combination of the three chief groups of organic foods, is therefore 

 also an essential requisite for an abundant fat deposit. 



E. GRAFE and D. GRAHAM 1 report an experiment on a dog in which they were 

 able to keep the body weight nearly constant for about two months by excessive 

 food with about 210 per cent of the minimum need of calories and with a diet 

 very rich in non-nitrogenous food-stuffs. No fattening occurred in this case; 

 the calories produced were considerably increased and the author considers this 

 case as an accommodation to the food and a luxus-consumption of non-nitrogenous 

 food-stuffs. 



Action of Certain Other Bodies on Metabolism. Water. If a quan- 

 tity in excess of that which is necessary, is introduced into the organism, 

 the excess is quickly and principally eliminated with the urine. This 

 increased elimination of urine causes in fasting animals (Vorr, FORSTER), 

 but not to any appreciable degree in animals taking food (SEEGEN, SAL- 

 KOWSKI and MUNK, MAYER, DuBELiR 2 ), an increased elimination of 

 nitrogen. The reason for this increased nitrogen excretion is to be found 

 in the fact that the drinking of much water causes a complete washing 

 out of the urea from the tissues. Another view, which is defended by 

 VOIT, is that because of the more active current of fluids, after taking 

 large quantities of water, an increased metabolism of proteins takes place. 

 VOIT considers this explanation the correct one, although he does not 

 deny that by the liberal administration of water a more complete washing 

 out of the urea from the tissues takes place. Opinions on this subject 

 are not yet in accord, and recently HEILNER has advocated VOIT'S 



1 Zeitschr. f . physiol. Chem., 73. 



2 Voit, Untersuch. iiber den Einfluss des Kochsalzes, etc. (Miinchen, 1860); Forster, 

 cited from Voit in Hermann's Handbuch, 6, 153; Seegen, Wien. Sitzungsber., 63; 

 Salkowski and Munk, Virchow's Arch., 71; Mayer, Zeitschr. f. klin. Med., 2; Dubelir, 

 Zeitschr. f . Biologic, 28. 



