134 
One point, however, is so interesting- that a word regarding it may 
be in place here. Comparisons of figures for amounts of hydrogen 
oxidized, as given in the tabular details of the experiments, show that 
if all the water formed by the oxidation of the hydrogen of the food 
and body material were eliminated through the lungs and skin and none 
through the kidneys, it would account for only about one-third of the 
water of respiration in the rest experiments and only about one-fourth 
of that in the work experiments. It is therefore evident that the 
increase of water of respiration and perspiration during periods of 
muscular activity is due not so much to an increased oxidation of 
hydrogen as to an increased excretion through the lungs and skin of 
water from some other source. 
The amounts of water eliminated by the lungs and skin in the dif- 
ferent periods of the day, as compared with the day as a whole, are 
shown in Table 146. 
Table 146. — Water eliminated by lungs and skin — Amounts per day, and rates and pro- 
portions for different periods. 
2 ■ 
i ; 
~ = 
- V 
o C 
- V 
M — 
J 8 
Total amount in 
24 hours. 
Rat 
e per hour. 
Aver- 
age 
for 24 
hours. 
Proportion of total for 24 
hours. 
Subject and kind of ex- 
periment. 
Day periods. 
Night periods. 
Day periods. 
Night periods. 
7 a. m. 
to 
1 p. m. 
1 p. m. 
to 
7 p. m. 
7 p. m. 
to 
1 a. m. 
1 a. m. 
to 
7 a. m. 
7 a. m. 
to 
1 p. m. 
1 p. m. 
to 
7 p. m. 
7 p. m. 
to 
1 a. m. 
1 a. m. 
to 
7 a. m. 
REST EXPERIMENTS. 
E. 0.. 9 experiments: 
Minimum 
Grams 
697 
1,212 
977 
821 
898 
859 
791 
879 
830 
Grams 
32.0 
55. 9 
39.1 
35.0 
37.5 
36.3 
33.7 
38.9 
36.0 
Grams 
23.4 
56.4 
41.8 
35.2 
37.9 
36.2 
34.6 
39.4 
36.0 
Grams 
30.4 
57.7 
43.7 
34.8 
39.3 
37.4 
33.1 
39.8 
35. 2 
Grams 
23.4 
.50.3 
38.2 
31.8 
34.9 
33.3 
30.0 
32.8 
31.1 
Grams 
29.0 
50.5 
40.7 
34.2 
37.4 
35.8 
32.9 
36.6 
34.6 
Pcrct. 
Per ct. 
Per ct. 
Per ct. 
Maximum 
Average 
A. W. S., 1 experiment: 
33 
24.0 
25. 7 
26.8 
23.5 

Average 
J. F. S., 3 experiments: 
3 
25.3 
25. 3 
26.1 
23.3 
9 
26.0 
26.0 
25.5 
22. 5 
Average of 13 ex- 
periments 
45 
939 
38.3 
40.3 
41.6 
36.4 
39.1 
24.5 
25.7 
26.6 
23.2 
WORK EXPERIMENTS. 
E. 0., 2 experiments: 
1, 762 
2,699 
2,275 
1.197 
2,094 
1,670 
89.2 
147.1 
120.3 
66.8 
134.5 
98.5 
69.4 
153.0 
108.5 
67.1 
140. 2 
111.5 
56.8 
107.7 
85.6 
31.7 
38.4 
34.8 
49.7 
77.2 
64.8 
30.8 
37.3 
33.5 
73.4 
112. 5 
94.8 
49.9 
87.3 
69.6 
Maximum 
Average 
8 
31.7 
28.6 
22.6 
17.1 
J. F. S., 4 experiments: 
Minimum 
Average 
12 
35.4 
40.1 
12.5 
12.0 
Average of 6 ex- 
periments 
20 
1,912 
107.2 
110.3 
55.1 
46.0 
79.7 
33.7 
34.6 
17.3 
14.4 
