398 On the Heat developed in Combustion 



Let us now see if, by adopting the analysis of Mr. 

 Cruickshanks with respect to the hydrogen, instead of 

 that of M. de Saussure, the calculation will agree better 

 with the experiment. 



We have seen that the quantity of water heated 

 1 80 Fahrenheit, which represents the quantity of 

 heat which must be developed in the combustion 

 of the 0.15 Ib. of alcohol, was . . . 9.9609 Ibs. 



And that the quantity answering to 0.5015 Ib. of 



carbon, which exists in the 0.85 of ether, was . 28.89 



We shall for the present add that which answers 

 to the combustion of 0.1003 Ib. of free combus- 

 tible hydrogen, which, according to Mr. Cruick- 

 shanks, ought to be found united to this quantity 

 of carbon in order to form the ether . . 41.123 



These three quantities of water together are the 

 measure of the heat which must be developed in 

 the combustion of one pound of sulphuric ether of 

 the kind employed in my experiments . . 79-9739 



The mean result of five experiments was . . 80.304. 



This coincidence between the calculation and the ex- 

 periment is, doubtless, too remarkable to be owing to 

 chance ; but I am ready to prove that it occurred without 

 being foreseen or expected. 



From all these results we may conclude, that one pound 

 of sulphuric ether, of the specific gravity 717 at the 

 temperature of 16 Reaumur, or of the same species 

 with that employed by M. de Saussure, should have 

 furnished in combustion enough of heat to raise 82.369 

 pounds of water 180 F., viz. : 



That furnished by 0.59 Ib. of carbon . . . 33.989 Ibs. 

 And that furnished by 0.118 Ib. of hydrogen . 48.380 



82.369 



