439 
recent experiments of Brix, at 972°. The numbers, however, 
are not strictly comparable. For, the heat evolved by the 
steam is truly its latent heat, or is due solely to its change of 
state, while the caloric evolved by ammoniacal gas, or muriatic 
acid gas, undoubtedly consists of two distinct parts, viz., of 
the heat of compression of these gases, and of that due to the 
chemical action exerted between them, supposed in the liquid 
condition, and water. 
‘*¢ Though I did not entertain any doubts as to the accu- 
racy of the results just stated, it was obviously desirable to 
resort to some experiments, if any such could be devised, by 
which they could be tested; and none appeared better suited 
to the purpose, than to pass ammoniacal gas into liquid muria- 
tic acid, and muriatic acid gas into liquid ammonia, and deter- 
mine, by the means already explained, the heat developed in 
each case. Such experiments were accordingly performed, care 
being taken that the gas introduced did not in amount. exceed 
what would be necessary for saturating the opposite principle 
contained in the liquid, and subjoined are the numbers to which 
they have conducted : 
Heat of ammoniacal gas passed into liquid muriatic acid, 2523° 
Heat of muriatic acid passed into liquid ammonia, . . 1527° 
_ Deducting from the former 940°, and from the latter 885°, the 
remainders are 1583° and 642°. Now, according to Andrews 
(Transactions, Royal Irish Academy, vol. xix. part 2), .129 of 
a gramme of ammonia, in the form of aqua ammoniz, in com- 
bining with liquid muriatic acid, evolves sufficient heat to raise 
31.09 grammes of water 5.58°, from which it is easy to caleu- 
late that it would raise an equal weight of water 1344°. But 
the heat evolved by equal weights of ammonia and muriatic 
acid, in combining with each other, are obviously reciprocally 
proportional to their atomic weights, so that, 1344 being the 
number for ammonia, 1344 X ae = 626 will be the number 
