on the Absorption of Carbonic Acid Gas.by Liquids. 9 
The pee forming the subject of the present paper, ex- 
tend over a part only of the ground. occupied by those of Saus- 
sure, but shone confined to the seem of carbonic acid, 
the similar but less varied observations of Dr. Henry. We be- ~ 
<b lieve that they furnish much more accurate results than the sim- 
‘i ple but rather rude methods used by these experimenters could 
cted to afford. Besides a great number of results obtained 
with different liquids and solutions at 60°, they include in the 
case of water a series of determinations at various stages of tem- 
perature, from 32° to 100°. " 
part from the Pian value which in a scientific sense must => 
always attach to the determination of exact numerical constants 
in subjects of this kind, there are points of the present enqui 
which claim attention from their bearing upon certain other 
branches of research. It will be seen, for example, in the sequel, 
that the absorption of carbonic acid gas by sulphuric acid at ordi- 
nary pea pe ony z far greater than chemists have hitherto sus- 
pected, and that the processes in which this gas,. before being 
estimated, is made to pass through or over a considerable volume 
of sulphuric acid, may lead to errors which although hitherto 
unnoticed, are too important to be overlooked. 
in a paper, on the analysis of the carbonates, published i in the 
American Journal of Science in 1844, we called attention to 
fact, that in using sulphuric or hapless acid for decomposing 
the carbonates, the resulting solution or mixture always retains 
an amount of carbonic acid too great to be neglected i S accurate 
research, and that this gas cannot be expelled without the use 
of @ continued boiling heat. Some experiments undertaken im 
the hope of “eating th precisely the absorbent power of these 
acids and solutions, led us into the more extensive field of en- 
quiry, of which we propose now to embody the results. 
Availing ourselves, at first, of the simple methods employed by — 
Dalton, Henry and Saussure, we found that with all care in the 
manipulation and in applying the proper corrections, we were 
unable to attain consistent and reliable results. 
_ In operating with a graduated tube over mercury, as was 
d by Dalton, and by Saussure for the more absorbent liquids, 
the great slowness of the absorption in many cases, rendered it 
impossible to detetmine, even after some days, whether the ae- 
tion was still in progress or had ceased, he form 
H 
: 
i 
“a 
this | ical aid, weeks of eye w 
sary to complete the absorption. 2 inued né thor 
Srconp Serres, Vol. VI, No. 16.—July, ims 13 
' = ‘ 
