Life of Count Rumford. 487 



the phenomena of heat is motion, and the laws of its 

 communication are precisely the same as those of the 

 communication of motion." 



Dr. Youmans, with admirable distinctness of state- 

 ment and with the full warrant of truth, distributes, 

 under the following specifications, a summary of the 

 claims of the American philosopher : 



" i. He was the man who first took the question of the 

 nature of heat out of the domain of metaphysics, where it had 

 been speculated upon since the time of Aristotle, and placed it 

 upon the true basis of physical experiment. 



" 2. He first proved the insufficiency of the current explana- 

 tions of the sources of heat, and demonstrated the falsity of the 

 prevailing view of its materiality. 



" 3. He first estimated the quantitative relation between the 

 heat produced by friction and that by combustion. 



"4. He first showed the quantity of heat produced by a 

 definite amount of mechanical work, and arrived at a result 

 remarkably near the finally established law. 



" 5. He pointed out other methods to be employed in deter- 

 mining the amount of heat produced by the expenditure of me- 

 chanical power, instancing particularly the agitation of water or 

 other liquids, as in churning. 



" 6. He regarded the power of animals as due to their food, 

 therefore as having a definite source and not created, and thus 

 applied his views of force to the organic world. 



" 7. Rumford was the first to demonstrate the quantitative 

 convertibility of force in an important case, and the first to 

 reach, experimentally, the fundamental conclusion that heat is 

 but a mode of motion." 



Nor did Rumford immediately find himself to be 

 followed, as he had so plainly intimated his expectations 

 and desire that he should be, by many inquirers pursu- 

 ing the path and method which he had opened. The 

 distinguished Dr. Thomas Young, at one time the 



