f the acid. During this operation, a large quantity
of oxygen gas, mixed with a small proportion of azotic gas, is
disengaged.

This acid, like all others, is composed of oxygen, united to an
acidifiable base, and is even the first acid in which the existence of
oxygen was well ascertained. Its two constituent elements are but weakly
united, and are easily separated, by presenting any substance with which
oxygen has a stronger affinity than with the acidifiable base peculiar
to this acid. By some experiments of this kind, it was first discovered
that azote, or the base of mephitis or azotic gas, constituted its
acidifiable base or radical; and consequently that the acid of nitre was
really an azotic acid, having azote for its base, combined with oxygen.
For these reasons, that we might be consistent with our principles, it
appeared necessary, either to call the acid by the name of _azotic_, or
to name the base _nitric radical_; but from either of these we were
dissuaded, by the following considerations. In the _first_ place, it
seemed difficult to change the name of nitre or saltpetre, which has
been universally adopted in society, in manufactures, and in chemistry;
and, on the other hand, azote having been discovered by Mr Berthollet to
be the base of volatile alkali, or ammoniac, as well as of this acid,
we thought it improper to call it nitric radical. We have therefore
continued the term of azote to the base of that part of atmospheric air
which is likewise the nitric and ammoniacal radical; and we have named
the acid of nitre, in its lower and higher degrees of oxygenation,
_nitrous acid_ in the former, and _nitric acid_ in the latter state;
thus preserving its former appellation properly modified.

Several very respectable chemists have disapproved of this deference for
the old terms, and wished us to have persevered in perfecting a new
chemical language, without paying any respect for ancient usage; so
that, by thus steering a kind of middle course, we have exposed
ourselves to the censures of one sect of chemists, and to the
expostulations of the opposite party.

The acid of nitre is susceptible of assuming a great number of separate
states, depending upon its degree of oxygenation, or upon the
proportions in which azote and oxygen enter into its composition. By a
first or lowest degree of oxygenation, it forms a particular species of
gas, which we shall continue to name _nitrous gas_; this is composed
nearly