141 
that the temperature of the incoming water current was as a rule above 
the dew point of the air inside the chamber. 
The fifth column shows the heat equivalent of the external muscular 
work done in the work experiments. It is measured by the bicycle- 
dynamo apparatus by which the mechanical work is transformed into 
electrical energy and into heat. 
According- to the figures of Table 148, in the 45 days of the 13 rest 
experiments the average amounts of heat given off per day from the 
skin (together with that in the expired air) was 1,669, in urine and 
feces 31, and in the water evaporated from the lungs and skin 550 
calories, making the whole daily elimination 2,250 calories. With 
E. O. the range in total heat eliminated was from 2,062 to 2,452 and 
the average 2,278 calories. With A. W. S. the range was from 2,226 
to 2,348 and the avereage 2,279 calories. With J. F. S. the range was 
from 2,065 to 2,297 and the average 2,136 calories. Taking into 
account the experiments with all the subjects, the average amounts of 
heat given off in different ways may be expressed in percentages as 
follows: 
Table 149. — Percentages of total energy given off from the body in different icays. 
Heat. 
In rest 
experi- 
ments. 
In work 
experi- 
ments. 
From skin by radiation and conduction (and in exhaled air) 
In urine and feces 
In water vaporized from lungs and skin 
Heat equivalent of external muscular work done 
Per cent. 
74.2 
1.4 
24.4 
Per cent. 
62.3 
.5 
30.8 
6.4 
Total. 
100.0 
100.0 
Energy given off from the body in different periods of the day. — Table 
150 summarizes the data for the outgo of energy during the different 
periods of the day in the 13 experiments covering 45 experimental 
days. As in the two previous tables, the figures for heat eliminated 
include (1) the quantity given off from the body and measured by the 
calorimeter; (2) that given off in the water vaporized during the same 
periods — i. e., carried awa} T from the bod} T in water vapor; and (3) the 
heat equivalent of the external muscular work done. The temperature 
of the body and the amount of material it contains varies somewhat 
from time to time. a It is assumed that at the hour when the experi- 
mental day begins and ends — 7 a. m. — the} T will be very nearly the 
same from day to day. If they are the same at these times, the total 
quantit} T of heat in the bod}^ at the beginning and end of each experi- 
mental day will be the same. The total quantity of energy given off 
a In order to obtain more accurate data regarding variations of body temperature 
and corresponding changes in the store of energy in the body from hour to hour, 
special apparatus lias been devised for measuring the temperature of the body. See 
Arch. Physiol.. [Pfliiger], 88 (1901), No. 9-10, p. 492. 
