106 •* THE HEAT DEVELOPED TN COMBUSTIOIf. 



substances; but the results of the experiments have been so 

 contradictory, and the methods employed so little calcula- 

 ted to inspire confidence, that the undertaking is justly con- 

 . sideied as very little advanced. 

 Unsuccessful I had attempted it at three different times within these 



attempts of the twent b j without success. After having made a 



author. ~ J ' _ ° 



great number of experiments with the most scrupulous care, 



with apparatus on which I had long reflected, and afterward 



caused to be executed by skilful workmen, I had found 



nothing however that appeared to me sufficiently decisive 



to deserve to be made public. A large apparatus in copper 



more than twelve feqt long, which I had made at Munich 



fifteen years ago; and another scarcely less expensive made 



at Paris four years ago, which I have still in my laboratory ; 



attest the desire I have long entertained of finding the means 



of elucidating a question, that has always appeared to me of 



great importance, both with regard to the sciences, and to 



Simple an-iac the arts. 



discovered. At length, however, I have the satisfaction of announcing 



to the class, that, after all my fruitless attempts, I have dis- 

 covered a very simple method of measuring the heat mani- 

 fested in combustion, and this even with such precision, as 

 leaves nothing to be desired. 



That the class may be the better able to judge of my 

 method of operating, and the reliance that may be placed on 

 the results of my experiments, I place my apparatus before 



The apparatus it. 



described. -j,^ p r j nc jp a ] p ar t f this apparatus is a kind of prismatic 



receiver, eight inches long, four inches and a half broad, and 

 four inches three quarters high*, formed of very thin sheets 



A calorimeter. f copper. This receiver, which well deserves the name, 

 already celebrated, of calorimeter, is furnished with a long 

 neck, near one of its extremities, three quarters of an inch 

 iu diameter, and three inches high, intended to receive and 

 support a mercurial thermometer of a particular shape. The 

 receiver has also another neck, an inch in diameter and the 

 same in height, situate in the centre of its upper part, and 



Worm of .-* closed by a cork. 



:<ev, fytaxi, Within this receiver, two lines above its flat bottom, is a 



particular kind of worm, receiving all the products of the 



combustion 

 * French measure. 



