Caloric necessary for supporting one pound
of carbonic acid in the state of gas, 20.97960.
[Note A: All these relative quantities of caloric are expressed by the
number of pounds of ice, and decimal parts, melted during the several
operations.--E.]
_Combustion of Hydrogen Gas._
In the combustion of one pound of hydrogen gas, 5 libs. 10 oz. 5
gros 24 grs. of oxygen gas are absorbed, and 6 libs. 10 oz. 5
gros 24 grs. of water are formed.
Caloric from each lib. of hydrogen gas, 295.58950.
Caloric from each lib. of oxygen gas, 52.16280.
Caloric disengaged during the formation of each pound of water, 44.33840.
Caloric retained by each lib. of oxygen after
combustion with hydrogen, 14.50386.
Caloric retained by each lib. of water at
the temperature of Zero (32 ), 12.32823.
_Of the Formation of Nitric Acid._
When we combine nitrous gas with oxygen gas, so as to form nitric or
nitrous acid a degree of heat is produced, which is much less
considerable than what is evolved during the other combinations of
oxygen; whence it follows that oxygen, when it becomes fixed in nitric
acid, retains a great part of the heat which it possessed in the state
of gas. It is certainly possible to determine the quantity of caloric
which is disengaged during the combination of these two gasses, and
consequently to determine what quantity remains after the combination
takes place. The first of these quantities might be ascertained, by
making the combination of the two gasses in an apparatus surrounded by
ice; but, as the quantity of caloric disengaged is very inconsiderable,
it would be necessary to operate upon a large quantity of the two gasses
in a very troublesome and complicated apparatus. By this consideration,
Mr de la Place and I have hitherto been prevented from making the
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