DR. DALTON ON THE CONSTITUTION OF THE ATMOSPHERE. 
363 
corking the phial immediately, leaving only a drop or two of water within. The 
cork was then well closed with sealing-wax. No. 1 was taken on the Mer de Glace, 
Aitgust 21, estimated at the height of 6000 feet above the sea; the second on the 
pass of the Simplon, August 29, at the height of 6174 feet above the sea; and the 
third on the Wenger n Alp on the 15th September, at the height of 6230 feet. These 
airs were analysed in October with the following results. 
Mer de Glace. — Average of four first experiments 20*2 oxygen per cent. 
Average of four last experiments 19*4 oxygen per cent. 
Simplon. — Average of four first experiments 1 9*98 oxygen per cent. 
Average of four last experiments 19'53 oxygen per cent. 
Wengern Alp. — Average of four first experiments 20*45 oxygen per cent. 
Average of four last experiments 20*11 oxygen per cent. 
It may not be amiss to subjoin a few experiments on air in close chambers, where 
a number of people have been congregated for two hours, the air being taken at the 
moment of breaking up. 
1802, March 6. — Got a 20-ounce phial filled at the close of a congregation of 
500 people assembled for two hours with 50 candles burning ; the air completely 
neutralized 150 grains of lime water, but took very little more; this accords nearly 
with 1 per cent, of carbonic acid gas. The oxygen was not examined. 
1824, November 28. — Examined the air at the close of an ordinary congregation, 
perhaps 200 people, retained for two hours. 
Average of five experiments gave the oxygen 20*42 per cent. 
1826, March 16. — Examined the air from a crowded congregation after two hours’ 
confinement, but some doors open. 
Average of four experiments gave the oxygen 20*23 per cent. 
There was a very slight appearance of carbonic acid each time a charge was passed 
up through lime water, a phenomenon never observed in ordinary atmospheric air. 
The general conclusions, it seems to me, to be drawn from these experiments are, 
that the proportion of oxygen to azote in the atmosphere on the surface of the earth 
is not precisely the same at ail places and times ; and that in elevated regions the 
proportion of oxygen to azote is somewhat less than at the surface of the earth, but 
not nearly so much so as the theory of mixed gases would require ; and that the 
reason for this last must be found in the incessant agitation in the atmosphere from 
winds and other causes. 
June 6, 1837- 
3 B 
MDCCCXXXVII. 
