ON THE HEAT DEVELOPED IN COMBUSTION. J J «£ 



be sensibly affected ; or indicate any thing except the confi- 

 dence I might place in the indications of the first, I resolved 

 to dispense with the trouble of using it. 



It may be seen by the description I have given of this ap- The apparatus 

 paratus, that it may be used very conveniently for ascertain- a PP llc ^bls to 



J J J asceriain the 



ing the specific heat of gasses ; as well as that .made appa- specific heat at 



rent in the condensation of vapours ; and generally in all re- 6 asJes - 

 searches, where the quantity of heat communicated by an 

 elastic fluid in cooling is to be measured. And as it would 

 be extremely easy, by very simple means, to separate com- 

 pletely the products of the vapours condensed in the worm 

 from the gnsses, that pass through it without being con- 

 densed, I cannot avoid hoping, that this apparatus will be- 

 come useful as an instrument to be employed in chemical 

 analyses. This however would only be an extension of the 

 method already employed with so much success by Mr. de 

 Saussure, and by Messrs. Gay-Lussac and Thenard. 



As toon as my apparatus was finished, I was eager to see Experiments 

 what quantity of heat I should find in the combustion of *° d withTa-*" 

 wax, and in that of olive oil, that I might afterward compare voisier's. 

 the results of my experiments with those of Mr. Lavoisier's: 

 and, as I have the most implicit reliance on every thing pub- 

 lished by that excellent man, I sincerely wished to find in 

 this comparison a proof of the accuracy of my method, and 

 at the same time a confirmation of the estimates of Mr. 

 Lavoisier. 



Sect. I. Experiments made with white wax. 



The air of the room being at the temperature of 6l° F., Combustion of 

 2781 grammes of water, of the temperature of 56* F., were whlte wax * 

 put into the receiver of the calorimeter, (including the quan- 

 tity of this liquor that represents the specific heat of the in- 

 strument) ; and, a lighted wax taper having been properly 

 placed at the entrance of the worm, the calorimeter waa 

 heated for 13 min. 26 sec; when, the thermometer announc- 

 ing that the water had acquired the temperature of 66* F., 

 the taper was extinguished. 



As. I took care to weigh the taper before it was lighted, I 

 found by weighing it at the end of the experiujec, that 

 l"63gr. of wax had been burned. 



Vol. XXXII— June, 1812. I T« 



