u6 Society for Experimental Biology and Medicine. 



ous to the glycocoll feeding, there was a loss of 0.435 gm. N. It 

 is believed that this loss includes the glycocoll nitrogen retained 

 temporarily. 



A second dog weighing in good condition 5.4 kg. fasted 

 for 10 days during which the body weight fell to 4.6 kg. The 

 nitrogen output on the last fasting day was 1 .697 gm. For five 

 days immediately following this, 1.496 gm. of nitrogen were given, 

 two-thirds of it (1.006 gm.) in the form of very pure gelatin and one- 

 third (0.490 gm.) in the form of beef heart. A total energy supply 

 of 130 cal. per kg. (chiefly carbohydrates) was maintained. On 

 the fifth day there were 1.55 gm. N in the urine. On the next day 

 the gelatin N was replaced by glycocoll N and, singularly enough, 

 the nitrogen output in the urine was exactly 1.559 gm. This, how- 

 ever, is probably a mere coincidence and is not to be interpreted 

 as showing that glycocoll N exerts the same sparing effect on the 

 body proteid as gelatin, for on the second day with glycocoll, the 

 nitrogen in the urine rose to 1.898 gm. 



A fasting period of five days was next introduced, the nitrogen 

 in the urine on the last day being 1.288 gm. For three days there- 

 after 7 gm. of glycocoll, containing 1.332 gm. N were given, and the 

 total energy supply was made up with carbohydrates and a small 

 quantity of fat (10 gm.) to 140 cal. per kg. The nitrogen loss rep- 

 resented by the urine alone on the three days was o. 1 25, 0.280 and 

 0.674 gm. respectively. Then the glycocoll was dropped and the 

 carbohydrates with a small quantity of fat were continued for two 

 days. The nitrogen in the urine for these days was 0.987 and 

 0.7 1 3 gm. respectively. A third day would probably have reduced 

 it still more, since as Landergren 1 has shown, it is possible to re- 

 duce the nitrogen output of a man to about one-third of what it 

 would be in fasting, by ingestion of carbohydrates alone. While, 

 therefore, there is an evident benefit, as regards waste of nitrogen, 

 conferred by the glycocoll while it is being ingested, the nitrogen 

 which it conserves is rapidly eliminated after the feeding period. 

 It is possible that this nitrogen is retained temporarily in the form 

 of glycocoll itself, since as shown by Parker and Lusk, 2 the 

 amount of glycocoll which may be removed by combination with 



1 Landergren : Review by I Iammarsten, Maty s Jahresber., 1 902, p. 685. 



2 Parker and Lusk: Amer. Journ. of Phystol. y 1 900, iii, p. 472. 



