608 On the Materiality of Caloric. 
which it was formed; and, on the same hypo- 
thesis, the absolute quantity of caloric in ice is 
diminished by friction and liquefaction, which 
is absurd: Count Rumford, also, ascertained 
that the specific heat of iron was not diminished, 
when converted by a borer into turnings, and 
consequently when it had been the source of 
much temperature. In explanation of these 
facts, we may be allowed to assume the com- 
munication of caloric from surrounding bodies, 
till this communication has been demonstrated to 
be impossible. But even were the impossibility 
established, it would yet remain to be proved, 
that the evolved caloric does not proceed from 
an internal source; and this can only be done, 
by an accurate comparison of the quantity of 
‘caloric in bodies, before and after friction. 
Now, in instituting this comparison, it is implied, 
that we possess means of determining the abso- 
lute quantity of caloric in bodies, and that we 
can compare quantities of caloric, with as much 
Certainty, as we can obtain from an appreciation 
by weight or by measure. Such perfection, how- 
ever, does not, I apprehend, belong to the 
present state of our knowledge respecting heat; 
for I. have always been distrustful of that part 
of the doctrine, which assigns the ratio of heat 
latent in bodies. The grounds of this distrust 
I shall state pretty fully—for, if it can be proved 
, 
