Mr. Dalton on the constitution of the atmosphere. 185 
sufficient reason, then the height of the azotic atmosphere 
will be only 44 miles. The very fine and attenuated carbonic 
acid atmosphere must ascend to the height of 10 miles, if a 
full atmosphere of this gas ascend to 30 miles ; and that of 
steam or aqueous vapour to the height of 50 miles, allowing 
the specific gravity of steam to be .625, and the weight of 
its atom to be 8. 
It may be worth while to contrast this view of the consti- 
tution of the atmosphere with the only other one, as far as I 
know, that has been entertained. 
According to one view. 
1. The volumes of each gas 
found at the surface of the earth 
are proportional to the whole 
weights of the respective atmo- 
spheres. 
Weight of 
atmosphere. 
Azote - = loo = 79 
Oxygen - = ^ = 21 
Aqueous vap. = —• = 1.33 
Carbonic acid = ^ = .10 
101.43 
According to the other view. 
1. The volume of each gas 
found at the surface of the 
earth multiplied by its specific 
gravity , is proportional to the 
whole weight of the respective 
atmosphere. 
Weight of 
sp. gr. atmosphere. 
Azote - = ~ x .97 = 16.6 
Oxygen = £xi.ii = 23.3 
Aque. va. = A- x .625 = 0 .g 3 
Car. acid =~x 1.53 = 0.15 
100.88* 
* In order to show the ratios more completely we have assumed the two compound 
atmospheres differing a little in the total weights. 
2 B 
MDCCCXXVI. 
