MATHEMATICAL THEORY OF HEAT. 409 



is the sole inventor of the steam-engine. Chaptal has 

 enriched the arts of Chemistry with the totality of the 

 fertile and ingenious processes which constitute their 

 prosperity. Even within this apartment has not an 

 eloquent voice lately asserted, that before Fourier the 

 phenomenon of heat was hardly studied ; that the cele 

 brated geometer had alone made more observations than 

 all his predecessors put together ; that he had with 

 almost a single effort invented a new science. 



Although he runs the risk of being less lively, the 

 organ of the Academy of Sciences cannot permit himself 

 such bursts of enthusiasm. He ought to bear in mind, 

 that the object of these solemnities is not merely to cele 

 brate the discoveries of academicians ; that they are also 

 designed to encourage modest merit ; that an observer 

 forgotten by his contemporaries, is frequently supported 

 in his laborious researches by the thought that he will 

 obtain a benevolent look from posterity. Let us act, so 

 far as it depends upon us, in such a manner that a hope 

 so just, so natural, may not be frustrated. Let us award 

 a just, a brilliant homage to those rare men whom nature 

 has endowed with the precious privilege of arranging a 

 thousand isolated facts, of making seductive theories 

 spring from them ; but let us not forget to state, that the 

 scythe of the reaper had cut the stalks before one had 

 thought of uniting them into sheaves ! 



Heat presents itself in natural phenomena, and in 

 those which are the products of art under two entirely 

 distinct forms, which Fourier has separately considered. 

 I shall adopt the same division, commencing however 

 with radiant heat, the historical analysis which I am 

 about to submit to you. 



Nobody doubts that there is a physical distinction 



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