Nitrogene 9,3
Oxygene 2,2
Carbonic acid 1,2
These results I gained from more than 20 experiments, so that I could
not possibly entertain any doubt of this accuracy.
I found, by making a person observe my respirations when I was
inattentive to the process, that I made about 26 or 27 natural
inspirations in a minute. So that calculating from the above
estimations, it would follow, that 31,6 cubic inches of oxygene were
consumed, and 5,2 inches of nitrogene lost in respiration every minute,
whilst 26,6 cubic inches of carbonic acid were produced.
To collect the products of a great number of natural expirations so
as to ascertain whether their composition corresponded with the above
accounts, I proceeded in the following manner.
I fastened my lips tight on the mouth-piece of the exhausted airholder,
and suffering my nostrils to remain open, inspired naturally through
them, throwing the expired air through my mouth into the airholder.
In many experiments, I found that in about a half a minute, I made in
this way 14 or 15 expirations. The mean quantity of air collected was
171 cubic inches, and consisted of
cub. in.
Nitrogene 128
Oxygene 29
Carbonic acid 14
Comparing these results with the former ones, we find the mean
quantities of air respired in equal terms rather less; but the
proportions of carbonic acid, nitrogene and oxygene in the respired
air, nearly identical.
_e._ To ascertain the changes effected in a given quantity of
atmospheric air by continued respirations, I breathed after a compleat
expiration, at temperature 63°, 161 cubic inches of air for near a
minute, making in this time, 19 deep inspirations. After the compleat
expiration, which was very carefully made, the gas filled a space
nearly equal to 152 cubic inches, so that 9 cubic inches of gas had
disappeared.