t is at the same time evident that on the transference of
the inflammable substance to the air a considerable part of the air is
lost. But that the inflammable substance[B] alone is the cause of this
action, is plain from this, that, according to the 10th paragraph, not
the least trace of sulphur remains over, since, according to my
experiments this colourless ley contains only some vitriolated tartar.
The 11th paragraph likewise shews this. But since sulphur alone, and
also the volatile spirit of sulphur, have no effect upon the air (Sec. 11.
_c._), it is clear that the decomposition of liver of sulphur takes place
according to the laws of double affinity,--that is to say, that the
alkalies and lime attract the vitriolic acid, and the air attracts the
phlogiston.

[Footnote B: "Das Brennbare."]

It may also be seen from the above experiments, that a given quantity of
air can only unite with, and at the same time saturate, a certain
quantity of the inflammable substance: this is evident from the 9th
paragraph, _letter b_. But whether the phlogiston which was lost by the
substances was still present in the air left behind in the bottle, or
whether the air which was lost had united and fixed itself with the
materials such as liver of sulphur, oils, &c., are questions of
importance.

From the first view, it would necessarily follow that the inflammable
substance possessed the property of depriving the air of part of its
elasticity, and that in consequence of this it becomes more closely
compressed by the external air. In order now to help myself out of these
uncertainties, I formed the opinion that any such air must be
specifically heavier than ordinary air, both on account of its
containing phlogiston and also of its greater condensation. But how
perplexed was I when I saw that a very thin flask which was filled with
this air, and most accurately weighed, not only did not counterpoise an
equal quantity of ordinary air, but was even somewhat lighter. I then
thought that the latter view might be admissible; but in that case it
would necessarily follow also that the lost air could be separated again
from the materials employed. None of the experiments cited seemed to me
capable of shewing this more clearly than that according to the 10th
paragraph, because this residuum, as already mentioned, consists of
vitriolated tartar and alkali. In order therefore to see whether the
lost air had been converted into fixed air, I trie