and we have not given it a
value, for want of a sufficient data to go upon.--A.]

_Combustion of Charcoal._

In the combustion of one pound of charcoal, 2 libs. 9 oz. 1 gros
10 grs. of oxygen gas are absorbed, and 3 libs. 9 oz. 1 gros 10
grs. of carbonic acid gas are formed.

Caloric, disengaged daring the combustion
of one pound of charcoal, 96.50000(A).

Caloric disengaged during the combustion of
charcoal, from each pound of oxygen gas
absorbed, 37.52823.

Caloric disengaged during the formation of
one pound of carbonic acid gas, 27.02024.

Caloric retained by each pound of oxygen
after the combustion, 29.13844.

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 deg.), 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 inconsiderab