e bottle. I afterwards invert the bottle and
permit the milk of lime to flow again into the bladder; I repeat this
running out and in several times. So much air by measure has been
absorbed as there now remains behind of milk of lime in the bottle.

These are the methods which I employed in my investigations of air. I
admit that they will not particularly please some, because they do not
decide with great exactness. They afforded me satisfaction, however, in
all my investigations; and people will often split a hair where it is
not in the least necessary.

+31. Continuation of the Experiment mentioned in Sec. 29+ ...

Anyone might object and say that the air obtained according to Sec. 29 is
perhaps nothing else than a dry acid of nitre converted into elastic
vapours. But if this opinion had any foundation, this air should not
only be corrosive, but should also produce nitre anew with alkalies.
This, however, does not occur. Nevertheless, this objection would
possess considerable weight were I not able to prove that several
substances produce the same air as the acid of nitre does during
distillation. But proof of this is not wanting.

I have proved in a treatise on manganese, which is to be found in the
Transactions of the Royal Swedish Academy of Sciences for the year 1774,
that this mineral is not soluble in any acid unless an inflammable
substance be added, which communicates the phlogiston to the manganese,
and by this means effects an entrance of the latter into the acids. I
have shown in the same place that vitriolic acid, nevertheless, during a
strong distillation with powdered manganese, unites with it and makes it
soluble in water; and if this manganese is separated again from the
vitriolic acid by means of precipitating agents, there are found in it
the most distinct traces of the inflammable substance.... I had already
observed a few years ago, that if in the calcination of manganese with
oil of vitriol in an open crucible, some coal dust was driven by the
current of air over the surface of this mixture, these fine coals took
fire in the same instant with very great brilliancy. I accordingly made
the following experiments.

+32. First Experiment.+--I mixed so much concentrated oil of vitriol
with finely powdered manganese that it became a stiff magma. I distilled
this mixture from a small retort on the open fire. In place of a
receiver I made use of a bladder, empty of air, and, in order that the
vapo