679 
APPENDIX. 
ir 
Note to Mn. W. Henry’s Paper on Heat. 
The argument, at page 611, which is the basis of my 
objections to the commonly employed mode of ascertain- 
ing specific caloric, I fear is not so fully and clearly stated, 
as the abstruse nature of the subject requires, 
Assuming two bodies, A and B, to beat the point of 
privation of temperature, or to possess no free caloric 
whatsoever, the quantity of combined caloric in each, 
according to Dr, Crawford’s theory, is directly propor- 
tional to the quantities of heat, necessary to produce 
equal elevations of temperature in the two bodies. Thus, 
if to attain a given temperature, A require caloric as 20, 
and B only as 10, the combined caloric of A, before this 
addition, is inferred to have borne to that of B, the ratio 
of 2tol. But it might, with equal or perhaps greater 
probability, have been assumed, that the combined caloric 
of A and B is znversely proportional to the quantities of 
heat, required to produce a given temperature ;—that A, 
for example, to attain a certain temperature, has absorbed 
more caloric than B, because in A less caloric existed, 
previously, in a state of chemical union, 
VOL. V, ZZ 
