on the Absorption of Carbonic Acid Gas by Liquids. 105 
weight of vapor contained in the gas was found to correspond 
closely with that proper to the temperature and a state of satura- 
tion. In other words, the. vapor mingled with the gas was at is 
um tension. As in its neutral state, the liquid of the gas- 
ometer contained most dissolved matter, it was to be inferred that 
the effect upon the tension of the vapor rising from it would then 
be most perceptible, and that therefore in the working condition 
of the apparatus, the saturation of the vapor could nat be less, — 
although it might be a small fraction more. Similar experiments 
with the gas under these conditions gave us, however, the same 
results. We concluded, therefore, that the dissolved matter in 
the gasometer, is not in sufficient quantity to produce - sensible 
modification of the tension of the aqueous vapor evolved, and 
that in all our experiments, we may assume the gas to - ig 
ated with vapor proper to the temperature at which we 
Of the Correction for Moisture —This being Jedeael ccm 
the pressure of the atmosphere and the vaporous tension jointly, 
requires a record of the barometer for each experiment. By the 
equal adjustment of the columns in the measuring tube, the en- 
tire tension of vapor and gas together, is the same at the close as 
at the beginning of the experiment, and is measured by the height 
of the barometer. 'The tension of the vapor remains unchanged, 
because it is vapor of igo eg and is condensed into water in 
pee as the gaseous space contraets in the progress of the 
absorption. If therefore v represent the @, ent a tion, or 
the volume which has disappeared, and v the volume of dry gas 
in V, estimated under the full atmospheric pressure ; and if p de- 
note ‘that pressure, in other words, the height of the barometer, 
and f the tension of the vapor proper to the temperature, we 
have v = V jaar § 
It is important to remark, that =A tension of the gas under 
which this absorption takes plac e, is p—f, and not p, and that in 
tabulating the results, the depsceieas: ebvorption should refer to the 
actual pressure of the gaseous atmosphere in the flask, and hot 
to the entire atmospheric pressure 
From experiments upon the absorption of carbonic acid gas at 
various pressures by water, Dr. Henry, as is well known, was 
led to infer that ong ns volumes are absorbed at all sir or 
what is the same thing, that the quantities of gas absorbed are 
_ exactly proportioned to the pressures. "This very simple law, if 
true, would 1 render the correction for moisture supeminowme ‘Por 
equal the volume absorbed at p. Thus V, the 
tion, that is, the volume disap at the pressure aaonating 
partly of F eee and fi rete of soe ee would be preeisely the sam 
¥ as alone which would disappear atthe same 
