THE FOOD AS A SOURCE OF ENERGY. 319 
pane Pre a iuoees Total Energy Metane 
ment Feed. as Urea, | vpurie | Energy |Perymm™| Energy 
No. Grms. Acid, |°% Cals” Nitrogen, ea 
Grms. F Cals. |Protein, 
als. 
1 TRIGGareve, doy ine Gintaleis aes e's 9.58 0.88 | 115.7 | 11.06 | 3.941 
2 MS ¥a3 ealag PAE EER RET 9.22 1.04 | 125.6 | 12.24 | 3.753 
3 Barley ws gies 3s ciecd eck sce ia 13.04 1.04 | 146.5 | 10.40 | 4.048 
4 Whey, rice, and flesh meal.| 59.89 | 1.17 | 410.0 | 6.72 | 4.636 
5 Nothing................. 9.35 0.45 83.7 | 8.54 | 4.344 
6 ap igtae wanda Rov aitacenl ae 6.48 0.29 56.4 8.33 | 4.379 
Kornauth & Arche * report the following results on the urine of 
swine fed chiefly upon cockle: 
Experiment Nitrogen, Carbon, Ratio, 
No. Grms. Grms. C:N. 
Mee sd raiehap aw rar arose 10.56 10.30 0.975 :1 
Diels aebwlng wea Wea 10.30 9.53 0.926 : 1 
Boxee weve mevadees 10.41 9.96 0.957 : 1 
Average.........] 10.42 9.93 0.953 :1 
The results, computed as in the previous case, make the average 
energy content of the urine 10.27 Cals. per gram of nitrogen, 
equivalent to a metabolizable energy of 4.067 Cals. per gram of 
protein. 
In the two fasting experiments of Meissl, Strohmer & Lorenz 
the ratios of carbon to nitrogen and of computed energy to nitro- 
gen are similar to those obtained with fasting carnivora. The 
abundant supply of proteids in the diet in the fourth experiment 
seems to have had the effect of reducing these ratios to values 
comparable with those obtained by Rubner for extracted meat 
and by Kellner for the digested protein of wheat gluten. These 
facts seem to indicate clearly that the nature of the proteid meta- 
bolism in all these animals is substantially the same. In the ex- 
periments in which ordinary grains were used, the computed energy 
content of the urine is notably greater relatively to its nitrogen. 
How far the excess of carbon found in these cases was due to an 
* Landw. Vers. Stat., 40, 177. 
