396 On the Heat developed in Combustion 



the quantity of water which the 15 per cent of alcohol 

 must heat (= 9.909), that which remains (= 70.3431 

 pounds of water) will be the measure of the quantity of 

 heat developed in the combustion of 85 per cent of 

 ether of the gravity of 717, which exists in this com- 

 bustible liquid. 



According to the analysis of sulphuric ether made by 

 M. d.e Saussure, we ought to find in one pound of this 

 liquid (of the specific gravity of 717) 



Carbon 0.590 Ib. 



Free and combustible hydrogen . . . . 0.194 

 Oxygen and hydrogen in the proportions necessary to 



form water . . . , .0.216 



Consequently, we ought to find in 0.85 pound of the 

 same kind of ether the following quantities of combus- 

 tible substances, viz. : 



Carbon . . " . . ... . 0.5015 Ib. 



Free and combustible hydrogen . . . 0.1651 



We shall now see if these quantities of combustible 

 substances are sufficient to account for the heat which is 

 manifested in our experiments. 



The 0.5015 pound of carbon ought to furnish suf- 

 ficient heat to raise 28.89 pounds of water 180 F. ; 

 and the 0.1651 pound of hydrogen sufficient to heat 

 67.64 pounds the same number of degrees. 



These two masses of water form together 96.53 

 pounds ; but we shall see that the quantity of heat fur- 

 nished by the 85 parts of ether in the experiments can- 

 not be greater than that which is necessary to heat 

 70.3431 pounds of water 180 F. 



As the experiments have been made with the greatest 



