Messrs. Allen and Pepys on Respiration. 409 
Here the increase of azote appears rather greater, viz. 110 
cubic inches, but the calculation in this case is made upon the 
gas expired, and, from the above statement, we may see, that 
the evolution of azote goes on diminishing ; we have some- 
times even found, that towards the close of an experiment it 
has been almost reduced to nothing. The question now is, 
whether this increase of azote can be owing to the residual 
gas contained in the lungs at the beginning of the experiment, 
or whether a portion of oxygen is not actually exchanged for 
azote, when pure oxygen gas is respired. 
Here it may be useful to compare the azote found in our 
former experiments on oxygen, with the present. 
Bar. 
Therm. 
Oxygen Gas 
inspired. 
Gas ex- 
pired. 
Defi- 
ciency. 
Time. 
Quantity 
respired in 
a Minute. 
Azote 
evolved. 
Inferred' 
Capacity 
of Lungs 
No. 1. 
0 
53 
3260 
3193 
67 
/ n 
9,20 
-P- 
OO 
I IO 
141 
2. 
3°>3 
70 
3420 
33 6 2 
58 
7> 2 S 
461 
1 77 
225 
3 - 
3 °nS 
70 
3130 
3060 
70 
8,45 
357 
187 
236 
4 - 
29,9 
5 1 
2668 
2544 
124 
13 > 
205 
i° 5 
1 33 
The greatest increase of azote was in the 2d and gd experi- 
ments, when the thermometer was at 70°, which might mate- 
rially influence the results : in the other cases, it was not 
higher than 53. 
From the experiments of Goodwin, we might be inclined 
to admit the capacity of the lungs, inferred from the 1st and 
4th experiments, as very possible ; but it seems difficult to 
conceive that it can amount to 23 6 or 225 cubic inches, and 
yet this must be the case, unless a portion of azote is given 
off from the blood, or there is some process in nature by 
which it is capable of being produced from oxygen. 
Having, by the kindness of our friend Henry Cline, jua. 
