440 Researches vpon the Heat developed 



Continuing to make use of the eslimaies of Crawford, 

 for the qiianiities of heat developed in the combustion of 

 hydrogen and carbon, we shall see if these estimates are 

 sufficient to account for the heat manifested in these five 

 experiments. 



As the eilier employed was a mixture of 15 parts of pure 

 alcohc;! of Lnwitz, and 85 parts of ether of the specific 

 gravity of 717 at the temperature of 16' Reaumur, and 

 consequently similar to the ether analysed by M. de Saus- 

 sure, we shall begin by determining the quantity of heat 

 which ought to to be developed in the combustion of these 

 fifteen parts of alcohol. 



As M. de SausHue has shown tliat in one pound of 

 Lowitz's alcohol (of the specific gravity of 792) there are 

 0-42S2 pound of carbon and O-IOIS pound of free hydro- 

 gen, \Ae ought lo find in 0M5 pound of this san)e liquid, 

 0*06i'i3 pound of carbon, and 0-01527 of free hydrogen. 



According to the estimate of Crawford, 006423 pound of 

 carbon ouglu to furnish a sufficiency of heat in its combus- 

 tion to raise the temperature of 3-7002 pounds of water ta 

 180° Fah.; and 001527 pound of hydrogen ought to fur- 

 nish enough lo raise to the same temperature 6*2607 pounds^ 

 o\ water ; and these two quantities of water making toge- 

 ther 9" 0609 pounds, is the measure of the quantity of heat 

 which must be developed in the combustion of the 15 parts 

 of alcohol which are found mixed with 85 parts of ether, 

 in order to form the combustible liquid employed under the 

 name of sulphuric ether in my experiments. 



Now, as one pound of this mixed liquid has furnished 

 in iis combustion enough of heat to raise to 180° of Fah- 

 renheit £0-304 pounds of water ; if wc deduct from this 

 mass the quantity of water which the 15 per cent, of alco^ 

 hoi must heat ( = 9 -pot)), that which rcniains ■( = 70-3431 

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

 heat developed in llie combustion of 85 per cent, of ether 

 of (he gravity 0!' 717, which exists in this combustible li- 

 quid. 



According to the analysis of sulphuric ether made by 

 ^'l. de Saussure, we ought to tind in one pound of this 

 liquid (of the specific gravity of 7 1 7) 



Carbon 0-590 lb. 



Free and combustible hydrogen 0- 1 94 



Oxygen and hydrogen in the proportions"! n-c>\(\ 

 necessary to form water j 



]• 



Consequently, we ought to find in 0-85 pound of the 



same 



