B44 Olservations on the Alsorption, of {Nov. 
the lightest liquids possess a greater power of absorbing gases than 
those the specific yravity of which is greater. Scarcely any other 
liquids are excepted from this rule but those the specific,gravities of 
which diifer but little ; and these exceptions vhs without doubt, the 
consequence of peculiar aflinities. * 
Probably the specific gravity of the gases themselves has an in- 
fluence on the quantity of them which a liquid is capable of absorb- 
ing, and on the time requisite for that purpose ; for all gases which 
are evidently heavier than atmospherical air are absorbed im greater 
quantity by water than azote, hydrogen, oxygen, and. carbonic 
oxide: and of two gases which are absorbed in equal. volumes bya 
liquid, the lighter requires a much longer time than the heavier. 
Thus naphtha absorbs olefiant gas much more slowly than it does 
nitrous oxide, 
13. Influence of Barometrical Pressure on the Absorption of Gases 
by Liquids. 
_ Dr. Henry caused carbonic acid in different states ob density to 
be absorbed by water, and found that in all cases the liquid’ ab-) 
sorbed its own bulk of the gas, whatever its density might be. He 
concluded trom this that the space which a gas occupies in water is 
in the direct (inverse?) ratio of the pressure. I have ascertained 
the accuracy of this conclusion by means of the contrivance de- 
scribed in paragraph 4, not only with respect to carbonic acid, the 
most absorbable gas employed by Dr. Henry, but likewise with re- 
spect to sulphurous acid gas, the absorption of which is nearly 50 
times greater. A volume of water which, under a barometrical 
pressure of 28:74 inches, and at the temperature of 621°, absorbed 
44 times its bulk of sulphurous acid gas, still absorbed the same 
volume of that gas when the barometrical pressure was reduced to 
14°33 inches, while the temperature continued the same. Oil of 
lavender, under a barometrical pressure of 6°89 inches, absorbed’ 
1°9 volume of carbonic acid: it absorbed the same bulk when the 
barometrical pressure was 28°74 inches. Olive oil gave the same 
results with carbonic acid gas under different degrees of barometrical 
pressure. Probably the same law holds with respect to all liquids.’ 
- It deserves attention that in liquids the quantities of gases ab- 
sorbed are as the compressions; while in solid bodies, as the gases 
become less dense, the absorption seems to increase. 
* Metallic Anise of great specific gravity must be capable of absorbing 2 
still smaller quantity of gas than the liquids employed in my experiments. It 
follows from this that in pneumatic experiments, when it is our object to measure 
the production of great quantities of carbonic acid, or any other pretty absorb- 
able gas, it will be adyautageous to employ saline solutions, and particularly 
solution, of common salt, which differs most from pure water of all that can be 
easily used, Common sea salt will answer still better than pure salt. A satarated 
solution of it absorbs not quite the third of its bulk of carbonic acid, and re- 
aes for that a far one time than pure water does to absorb its own volume of 
the gas, 
