on the Subject of Heat. 191 



was more vibrating or heavier when the charge was 

 fired without a bullet than when the elastic fluid gener- 

 ated by the combustion was obliged, in order to get 

 room for action, to push slowly before it one or more 

 balls, which were anything but light. On careful con- 

 sideration it seems to me that this circumstance is more 

 than sufficient to explain in a satisfactory manner the 

 results of the experiments in question, although I am 

 perfectly free to confess that I never could reconcile 

 myself to the hypothesis which has been developed 

 with regard to caloric. 



The above-mentioned occurrence made so deep an im- 

 pression upon me, that I could hardly wait long enough 

 to procure the necessary instruments before undertak- 

 ing a number of successive experiments upon heat, in 

 order to arrive at some conclusion with regard to its 

 character, as well as to the manner of its operation. 



I proposed, first of all, to undertake various experi- 

 ments on what has since been called the specific heat of 

 bodies. For this purpose, I procured from Mr. Fra- 

 ser, New Bond Street, London (now physical and 

 mathematical instrument maker to the King of Eng- 

 land), a considerable number of solid balls of precisely 

 the same diameter, namely, one inch. Some of these 

 balls were of gold, some of silver ; in short, they all were 

 of one metal or another, or of some solid substance 

 easily turned in a lathe. Each of these balls was sus- 

 pended by a thin silken cord, and I proposed to heat 

 the balls in certain liquids up to a given temperature, 

 and then to plunge them into a known quantity of water 

 which had been cooled in the same proportion. I drew 

 this inference, that the degree of temperature which 

 the balls communicated to the known amount of water, 



