W. A. Norton—Theories of Heat. 197 
; e 
cussion, we recognize the high probability that heat and light 
originate in some mode of motion occurring in the ethereal 
Against this conception of the origin and nature of heat, the 
objections that have been brought forward against the prevail- 
of heat and light, are in full accordance wit 
esis. Again, the 
Seem improbable, from our ordinary point of view, that asa: 
i u 
p 
result should follow from ethereal impulsive actions ; , 
ave already seen (p. 192) that the same potential repulsive 
* What I conceive to be the actual nature of the change which ~ Par mera 
: 93) the true process of heat-evolution, has already been 
