THE RELATIONS OF METABOLISM TO FOOD-SUPPLY. 127 
save one the gain of nitrogen by the body showed a marked increase, 
and this, it is to be noted, after the feeding had been continued for 
a considerable time. The one exceptional case, on wheat straw, 
is readily explained by the obvious effect of this material in increas- 
ing the metabolic nitrogen of the feces and thus diminishing the 
apparent digestibility of the protein of the ration. Had account 
been taken of these metabolic products, the increased gain of 
nitrogen by the animals would doubtless have been more marked 
inall cases. This gain, it would seem, may fairly be ascribed to the 
large additions of digestible non-nitrogenous matter derived from 
the hay: or straw added. 
CoMPARATIVE EFFECTS OF Fat AND > CARBOHYDRATES. —C. Voit * 
found the hexose carbohydrates to be superior to fat in diminishing 
the proteid metabolism. He gives the following comparisons: 
Food per Day. Urea 
Date. per Day, 
Meat, | Carbohydrates or Fat, Grms. 
Grms. Grms, 
Nov. 16-22, 1857............05. 150 | 150-350 sugar 13.4 
“©” 92 Dec. 2, 1857 ....2...0.. 150 250 fat 15.6 
Oct. 28-Nov. 8, 1857 a Mana one 176 100-364 starch 15.1 
Nov. 815, 9 © weeeeeeeeee 176 250 fat 16.2 
Feb. 23-25, 1861............... 400 200 fat 31.9 
© O58 cece ee 400 250 starch 30.5 
“ 28-Meh. 8, 1861 wesw eens: 400 250 sugar 30.3 
June 19-23, 1859........2....0. 500 250 fat 38.5 
 23—' ay Oe Fannay Shi saite Sha ay 500 300 sugar 32.7 
© QB-29 ccc e eee ees 500 200 « 35.6 
“ 3o_Tely 2, 1859 s¢ iosceinon 500 100 “ 37.9 
299 B65 cus cade eee we 800 250 starch 52.8 
Pep 338° eR ee 800 200 fat 54.7 
26, 1864. .....200- *....{ 1000 0 73.5 
ard 26 oe rs Pik oe Anastasios 1000 100 starch 68.5 
“« 97 RN or on ae taae 1000 400 “ 60.2 
“oF 1864 0.00... e ee 1000 0 ; 
A aT Ayg ee - =} 1000 100 fat 74.5 
Ge cee oD 300 « 69.3 
a aoe cae asain eeNeee 1000 0 80.2 
2219. 1859). oes sae eee ye 2000 200-300 starch 128.4 
a eg, en pean 2000 250 fat 135.9 
* Zeit. f. Biol., 6, 447. 
