Atmospheric Air and Oxygen Gas by Respiration • 253 
No. 
Time. 
Cubic inches 
of common air 
Cubic Inches 
of Gas 
Deficiency. 
Inspired. 
Expired. 
1 . 
time not noted 
3760 
3741 
19 
2. 
1 1 minutes 
39OO 
3869 
31 
3 - 
*°2 
3624 
3620 
4 
4 - 
1°2 ~ — 
357 0 
3550 
20 
5 - 
1 1 — — 
3685 
3 %3 
32 
6. 
11 " 
33 80 
3355 
25 
7- 
10 2 
3180 
3141 
39 
8. 
10 1 — — 
3360 
3298 
6 2 
9- 
ioi — — 
3290 
32 67 
23 
10. 
1 ! — 
358 o 
3543 
37 
In this last experiment we ascertained that the expired gas 
contained 8 per cent, of carbonic acid . 
The breathing in these cases was as nearly natural as we 
conceive it possible to be in any apparatus ; the operator was 
scarcely fatigued, and his pulse not raised more than about one 
beat in a minute ; the respirations however were deeper and 
fewer than natural, amounting only to about 58 in eleven 
minutes, whereas from repeated observations at different and 
distant times he makes 19 in a minute. The smallness of the 
deficiency surprised us very much, as, from the reports of 
other experimenters we had been prepared to expect a much 
greater loss. It might be objected that the air was rarefied 
by passing through the lungs ; but this was almost imme- 
diately counteracted by the mass of quicksilver in the gaso- 
meters, which amounted at least to one hundred and fifty 
pounds ; and we have repeatedly noticed, that air under these 
circumstances has suffered no perceptible diminution by stand- 
ing for a considerable time ; in one case, in which air from 
