1817.) during the Year 1816. : 13 
In such cases there must exist a chemical affinity between the liquid 
and the gas absorbed. Yet in every other respect the absorption of 
these gases is similar to that of the least absorbable gases. Hence 
if we admit the action of chemical affinity in the one case, I do not 
see how we can refuse it in the other. 2. Water absorbs a deter- 
minate bulk of every gas. But the proportion absorbed varies ex- 
ceedingly in the different gases. Of some gases it absorbs its own 
bulk; of others, only s4- of its bulk. Now if the absorption be 
merely mechanical, 1 can see no reason for this difference ; but if 
there be an affinity between the gas and the liquid, the quantity 
absorbed must depend upon the balance between the affinity and the 
elasticity of the gas, and of course must be regulated by that affinity. 
In the year 1812 M. de Saussure published a very elaborate paper 
On the Absorption of Gases by different Bodies. ‘This paper I 
translated, and inserted in the sixth volume of the Annals. The 
experiments relate chiefly to the absorption of gases by solid bodies. 
But the author added a section, in which he examines the absorption 
of gases by liquids. He shows, 1. That the law established by 
Dalton, and considered by him as a necessary consequence of the 
absorption of gases by liquids, being mechanical, does not hold ; 
namely, that liquids absorb always =, <4, sip or =, of their 
bulk of gases. 2. That the quantity of the same gas absorbed by 
different liquids is not the same, as Dalton had supposed, but very 
different. 3. That the order of the absorption of gases differs in 
different liquids. Thus naphtha absorbs more olefiant gas than it 
does of carbonic acid, while olive oil absorbs more carbonic acid 
than olefiant gas. Saussure also endeavoured to prove by experiment 
that the absorption of mixed gases by liquids does not follow the law 
established by Mr. Dalton. But Mr. Dalton in his vindication of 
his theory (Annals, vii. 215), has shown that Saussure’s experi- 
ments coincided with his theory, provided we substitute the rate of 
absorption as determined by Saussure for what he himself had esta- 
blished. When I said “ it would appear from these experiments 
of De Saussure that Mr. Dalton’s theory is erroneous in every parti- 
cular,” I alluded to the theory as given by Mr. Dalton in his ori- 
ginal paper. My observation could not be supposed to apply to any 
new modification of the theory founded upon these very experi- 
ments. I find myself still unable to assent to the opinion that the 
absorption of gases by liquids is entirely mechanical, because several 
of the phenomena appear to me incompatible with that opinion. 
Mr. Dalton will find, if he take the trouble to consult the third 
volume of the fourth edition of my System of Chemistry (p. 517), 
that I considered his experiments on the absorption of mixed gases 
by water as accurate, though { explained the fact without having 
recourse to the doctrine of mere mechanical absorption. 
1V. CRYSTALLIZATION, 
1. Supposed Effect of Air on the Crystallization of Liquids.—M. 
Geiger, of Heidelberg, relates a fact which he considers as illus- 
