354 Mode of reasoning in Chemistry. 
ease of a freezing mixture is explained so far only, as it i 
shown to be an individual example of the foregoing general 
law. 
kind. What is enlargement of capacity, but am increased 
power of absorbing heat? Water, then, during its forma- 
tion from ice, absorbs heat, because it has an increased power 
of absorbing heat; and this increase of power itself is 
is inferred from the fact that it does absorb #. So that the 
explanation comes to this: Water absorbs heat, because it ab- 
sorbs heat. All we know about the matter is the fact that 
heat is capable of existing under two different forms, the sen- 
sible and the latent ; and the knowledge of this faet is of the 
ghest importance, since it enables us to account, mostelearly, 
for almost all the changes of temperature which result from a 
change of state in bodies, whether to the solid, the fluid, or 
the zriform. But Black himself seems to have 
erred in supposing that he had done something more, in in- 
vestigating the cause of fluidity, than barely to ascertain this 
fact. seems to have supposed that he saw the reasou 
why the absorption of a portion of latent heat should main- 
dy in the fluid state. But I think we can perceive 
no connexion between latent heat and fluidity; that is, we 
an see no reason why a body’s hap ening to contain a por 
tion of heat in the latent state, should keep it fluid. . We have 
before seen that the mere separation of the particles of a solid 
body, is not sufficient to account for fluidity ; and, moreover, 
if that only were necessary, it is sensible and not latent heat, 
that causes expansion, and that might therefore be supposed to 
some approaches towards the fluid state. 
The foregoing examples of loose or defective reasoning, 
are adduced to show, that something remains to be done to 
improve the logic of chemistry ; nor could we recommend 
to the young chemist any thing better, than to study the 
Writings of those metaphysical authors, who exhibit the true 
of physical reasonings. These writers do indeed 
na in some particulars; but the student will, at least, 
excited by a perusal of them to think for himself. ong 
