B52 Mode of reasoning in Chemistry. 
duced to account for itself; and we say that water has a 
stronger affinity for alcoho} than camphor has, because it sepa~ 
rates alcohol from camphor, and that it separates alcohol from 
camphor because it has a stronger affinity for it. In such an 
explanation of this phenomenon, therefore, we ought to im- 
ply nothing more than this, that here is an instance of the 
operation of that genera) Jaw of attraction, that bodies have 
different degrees of affinity for each other. A lump of chalk 
refuses to dissolve in water; one says, it is owing to a want 
of affinity; another says, its insolubility is the result of cohe- 
sion. Both evidently fall short of accounting for the pheno-— 
menon; for, in the one case, the want of affinity itself was 
the thing to be accounted for; and, in the other case, its in- 
solubility remains after its cohesion is destroyed. As the on-' 
ly proof we have of the want of affinity of chalk for water is 
the fact that it will not enter into combination with it, to as- 
cribe the phenomenon to a want of affinity, is merely to say, 
it. Nor is its insolubility merely the result of cohesion ; for, 
overcome its cohesion, as far as possible, by grinding it to pow- 
der, it isstill insoluble. Then ecompose it by muriatic acid, 
and precipitate it by carbonate of potash ; it is now in a state 
of impalpable powder, and devoid of cohesion ;* yet it is as 
insoluble as before. The fact is, we can assign no adequate 
reason why muriatic acid should dissolve chalk, and why wa- 
ter should not. All we can do with phenomena of this kind, 
48 to arrange such as are analogous into separate classes. 
ay derive a further illustration of the erroneous or 
defective reasoning complained of, from some of the explana- 
tions whi iven ander the head of caloric. So far as 
and in pointing out the conformity of individual cases to these 
aws,—so far the way is clear. But when the chemist at- 
tempts to assign a reason why heat should produce these ef- 
fects, that moment he gets beyond his depth. That heat ex- 
pands | tes; that it radiates from their surface, and with 
Various degrees of facility from surfaces of different colors 
- rant naan fs generally. understood to be ‘that force which unites the in- 
tegrant particles of the Brecipitate seppoeed Man bit cack cette, or 
isi probable they are? pposed are united with each other, © 
