On the Materiality of Caloric. 621 
phenomena of heat differ from the known and 
acknowledged phenomena of motion. At pre- 
sent, however, I have not leisure to pursue 
the subject at much length; and, though several 
points of disagreement would doubtless be 
found, I shall mention only one of the most 
marked and decisive. ae 
Motion is an attribute of matter, indepen- 
dently of which it cannot possibly subsist. If 
therefore, the phenomena of-heat can be shewn 
to take place, where matter is not present, we 
shall derive, from the fact, a conclusive argu- 
ment against that theory! of heat, which assigns 
motion as its cause. Now, in the experiment 
of Count Rumford, before alluded to, héat 
passed through a torricellian vacuum, in which, 
it need hardly be observed, nothing could be 
present to transport or. propagate motion. 
This experiment, in my opinion, decidedly 
proves, that heat can subsist independently 
of other matter, and consequently of motion— 
in other words that heat is a distinct and peculiar 
body. 
