440 



for muriatic acid. The following, therefore, are the compara- 

 tive results, the numbers in first column being the differences; 

 those in the second, the heat of the chemical action between 

 aqueous ammonia and muriatic acid, as inferred from the ex- 

 periments of Andrews; and those in the third, the excesses of 

 the former over the latter : 



Differences. Andrews. 



Ammoniacal gas into aqueous acid, . 1533° 1344° 239° 

 Muriatic acid gas into aqueous ammonia, 642° 626° 16° 



" A glance at these numbers is sufficient to show that, 

 when muriatic acid gas is passed into aqueous ammonia, the 

 heat extricated exceeds that obtained when the gas is passed 

 into water, by almost exactly the heat of the chemical action of 

 aqueous muriatic acid and ammonia ; while, as respects the 

 case of ammoniacal gas passed into water and aqueous acid, 

 this equality is wanting, the estimate by difference exceeding 

 the direct determination by 239°. 



" This is a very curious result, and I was so startled by it, 

 that it was not my intention to give publicity to these experi- 

 ments until I had more frequently repeated them, and exe- 

 cuted others, which I had planned with the view of throwing 

 additional light upon the subject of my inquiry. In entering, 

 however, upon this new investigation, I had the misfortune to 

 lose, by an accident, both my thermometers, and as I do not 

 anticipate being able to return to it for a considerable time, I 

 gladly avail myself of the permission of the Council, to submit 

 these researches, in their present state, to the judgment of the 

 Academy. I entertain, indeed, a very confident hope, that the 

 numbers at which I have arrived will eventually be found to 

 be very close approximations to the truth. Assuming such, 

 for a moment, to be the case, and, in addition, that the results 

 of Dr. Andrews, in relation to the heat arising from the che- 

 mical action of aqueous ammonia and aqueous muriatic acid, 

 are rigorously correct, it has occurred to me that my results 

 admit of the following interpretation : 



