318 PRINCIPLES OF ANIMAL NUTRITION. 
wheat gluten, and assuming that the large amounts of soluble 
carbohydrates digested had no effect on the potential energy of the 
urine, the results were as follows: 
Protein Digested Difference in Energy of Urine.* 
none 1 
rms. . 
Total, Cals. Per ree Eveeety 
ORG Pte ah bas aeehh's audiiats 117 256.1 2.189 
OS UHigwcqhnes chm ne te pine 160 240.3 1.502 
MO Vtg bio 08 Nhe 2 iin RS B/E 122 192.6 1.579 
Average.......... eee eee 133 229.7 1.727 
* Corrected to nitrogen equilibrium. 
It will be seen that the loss of energy in the urine is much 
greater than in the case of the gluten or than in Rubner’s experi- 
ments with carnivora. Since it is improbable that the soluble 
carbohydrates of the molasses escape oxidation, it would appear 
that some of the nitrogenous material of the latter must have 
passed through the system unmetabolized. Kellner suspects that 
it is made up in part at least of xanthin bases. 
If we consider the nitrogen of the molasses to represent crude 
protein (NX6.25) with a heat value of 5.711 Cals. per gram, the 
metabolizable energy per gram would be 3.984 Cals. In view, 
however, of the fact that only a very small proportion of the nitro- 
gen of the molasses is in the proteid form, such a calculation seems 
of doubtful value. 
Swine.—In the investigations of Meissl, Strohmer and Lorenz * 
upon the production of fat from carbohydrates (p. 176) the carbon 
and nitrogen of the urine were determined in six experiments. 
Applying to the results Zuntz & Hagemann’s method of 
computation (p. 315) we obtain the following estimates for the 
energy per gram of nitrogen in the urine of the hog in these 
experiments and for the corresponding metabolizable energy of the 
digested protein: 
* Zeit. f. Biol., 22, 63. 
