( INTERNAL WORK. 387 
in the manner described on page 76 on the assumption that the fat 
has the composition C 76.54 per cent., H 12.01 per cent., O 11.45 
per cent., and the carbohydrates that of starch. 
Fifth, on the basis of the chemical processes thus computed the 
amount of energy set free is estimated from the known (average) 
heats of combustion of the materials oxidized. 
While the calculation involves numerous assumptions, and 
while, therefore, the result is of the nature of an approximation, 
most of the assumptions are so nearly correct as not to contain the 
possibility of serious error. The two which seem most questionable 
are the peculiar method of computing the digestibility of the food 
and the proteid metabolism, and the computation of the proximate 
composition of the urine. 
INFLUENCE oF Foop ConsuMPTION ON MetTaso.ism.—The 
influence of the ingestion of food in increasing the oxygen con- 
sumption and the energy metabolism of the animal is illustrated by 
the following tabulation of the results obtained in Period b (loc. cit., 
p. 282). (The animal was standing quietly, but otherwise was in 
a state of rest.) 
In the Morning, . . Later Stage After 
Fasting. Immediately After Feeding. First Feeding. 
Per Kg. Live Per Kg. Live Per Kg. Live 
Weight per Ss Feed Eaten. | Weight per iS Weight per | 
No. of Minute. a Minute. a Minute. @ 
Experiment. e. 4 4 
ow ae os 
as oS iF: aZ aol ae asd aol aa 
oe Bo . | mS! Oats oa .( 82 ./ad| oe. Bo | ag 
mas 538 2! and | Hay, Se) has = we Bea ae 
K@°) 298 | 3” |Straw,|Grms pas aoS|3 | Kae] aes] 3 
Os | mas ona O8 |m@2°}o |Os |Ra | 5 
Ss) qa |e ? is) a |e is) A | 
ne 2300 | 1500]]......]...... .; 3.602/18.365] 3.5 
ue 2300 | 1500J]......]...... 3.613/18.798) 2 
10.5 
10.5 
10.5 
11.0) 2100 | 1000 } 3.418/17.431] 0.6) 3.823/19.159! 4.5 
10.5] 2280 | 1420 | 4.039)20.889] 0.8) 3.737/19.220) 4.5 
11.0] 3180 3.745/18.913} 0.5) 3.739/19.304) 3.5 
17.5] 3150 3.584]17.647| 0.6] 3.169]16.134) 4.0 
og 2 AL 2BOO | LOO) ses ae ade cee s 3.564/18.318} 2.5 
11.0] 2330 | 1430 | 3.716]18.931) 0.5 
11.0 0 0 | 3.385]17.247| 0.5) 4.174)20.450/ 3.5 
11.0 [8 |} 2500) wv aeals bees 3.914/19.333] 3.5 
Averages ..| 3.339/16.929 |11.5] 2173 | 917 | 3.648/18.510) 0.6) 3.704/18.787| 3.5 
* Animal was uneasy. 
