INTRODUCTION. 



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

 prevailing view of its materiality. 



III. He first estimated the quantitative relation between the heat 



produced by friction and that by combustion. 



IV. He first showed the quantity of heat produced by a definite 



amount of mechanical work, and arrived at a result re- 

 markably near the finally established law, 







V. He pointed out other methods to be employed in determining 

 the amount of heat produced by the expenditure of me- 

 chanical power, instancing particularly the agitation of 

 water, or other liquids, as in churning. 



VI. He regarded the power of animals as due to their food, there- 

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

 applied his views of force to the organic world. 



VH. Eumford was the first to demonstrate the quantitative con- 

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

 reach, experimentally, the fundamental conclusion that heat 

 is but a mode of motion. 



In his late work upon heat, Prof. Tyndall, after quoting co- 

 piously from Eumford's paper, remarks : " "When the history of the 

 dynamical theory of heat is written, the man who in opposition to 

 the scientific belief of his time could experiment, and reason upon 

 experiment, as did Kumford in the investigation here referred to, 

 cannot be lightly passed over." Had other English writers been 

 equally just, there would have been less necessity for the foregoing 

 exposition of Eumford's labors and claims ; but there has been a 

 manifest disposition in various quarters to obscure and depreciate 

 them. Dr. Whewell, in his history of the Inductive Sciences, 

 treats the subject of thermotics without mentioning him. An em- 

 inent Edinburgh professor, writing recently in the Philosophical 

 Magazine, under the confessed influence of 'patriotism,' under- 



