420 PRINCIPLES OF ANIMAL NUTRITION: 
From the comparisons of cellulose and cane-sugar made by v. 
Knieriem (loc. cit.) and cited on p. 161, the following figures for the 
net availability of the energy of the latter substance may be com- 
puted: 
“a a Gain. 
a > Metab- Net 
g14 élizable;| 7 A 
a] ow Food per Day. Energy Over ability. 
® ° of Food, Total, Basal | Per Cent. 
iF 6 Cals. Cals. Ration, 
ical Z Cals. 
TE) S | Milk sasenea vinnie eases 350.1 | —37.9 
IV| 4 “ +11 grms. cane-sugar..| 393.7 | —15.9 22.0 50.5 
Vi 3 “ 433 “ mi « ,.| 480.7 | +69.9 | 107.8 82.5 
A series of experiments by May * upon the effect of fever on 
metabolism affords incidentally a few data bearing on the availa- 
bility of the energy of dextrose. In his experiment No. 5 (loc. cit., 
p. 23) the ingestion of 30 grams of grape-sugar, an amount approxi- 
mately equivalent to the fasting metabolism, caused no increase in 
the computed heat production as compared with that during fasting. 
In this experiment there was no fever. In Experiment No. 6 (p. 25), 
with fever, the ingestion of the same amount of grape-sugar pro- 
duced a computed gain of 2.88 grams carbon as fat, but caused no 
increase in the computed heat production. Experiment No. 7 
(p. 26) was similar to No. 6, but showed a decrease in the computed 
heat production, which, however, coincided with a decrease in the 
fever. On the whole, May’s results appear in accord with Rubner’s 
hypothesis of a substitution of the heat resulting from digestive 
work for that arising from the metabolism of tissue. 
Pentoses.—Cremer’s experiments + with rhamnose upon rabbits, 
cited in Part I, p. 157, afford data for computing the net availa- 
bility of this representative of the pentoses. For this purpose 
Cremer computes from the excretion of nitrogen and carbon (neg- 
lecting the feces), in the manner described in Chapter VIII, p. 253, 
the amount of energy liberated by the metabolism of protein and 
fat in the body, assuming that the rhamnose, after deducting the 
small amounts in feces and urine, was completely oxidized. The 
following are the results for each day of the four experiments: 
* Zeit. £. Biol., 30, 1. + Ibid., 42, 451. 
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