158 Count Rumford’s Enquiry concerning the Nature of Heat , 
consequence of these actions, have acquired the same tempera- 
ture, or until their vibrations have become isochronous. 
According to this hypothesis, cold can with no more propriety 
be considered as the absence of heat, than a low or grave sound 
can be considered as the absence of a higher or more acute 
note; and the admission of rays which generate cold, involves 
no absurdity, and creates no confusion of ideas. 
On a superficial view of the subject, it may perhaps appear 
difficult to reconcile solidity, hardness, and elasticity, with those 
never-ceasing motions which we have supposed to exist among 
the constituent particles of all bodies ; but a patient investiga- 
tion of the matter will show, that the admission of that supposed 
fact, instead of rendering it more difficult to form distinct and 
satisfactory ideas of the causes on which those qualities of bodies 
depend, wall rather facilitate those abstruse researches. 
Judging from all the operations of nature, of the causes of 
which we are able to form any distinct ideas, we are certainly 
led to conclude, that the force of dead matter, (and perhaps of 
living matter also,) or its power of affecting, that is to say, of 
moving, other matter, or of resisting its impulse , depends on its 
motion. 
If, therefore, solid (or fluid) bodies have any powers whatever, 
either of impulse or of resistance, it appears to me to be more 
reasonable to ascribe them to the living forces residing in them, 
—to the never-ceasing motions of their constituent particles, — 
than to suppose them to be derived from their want of power, 
and their total indifference to motion and to rest. 
No reasonable objection against this hypothesis, (of the in- 
cessant motions of the constituent particles of all bodies,) founded 
on a supposition that there is not room sufficient for these 
