lt; and making the air (which was generated in great plenty,
on the application of heat) ascend into a tall glass vessel full of
quicksilver, and standing in quicksilver, the whole produce continued a
considerable time without any change of dimensions. I then introduced a
small quantity of water to it; when about three fourths of it (the whole
being about four ounce measures) presently, but gradually, disappeared,
the quicksilver rising in the vessel. I then introduced a considerable
quantity of water; but there was no farther diminution of the air, and
the remainder I found to be inflammable.

Having frequently continued this process a long time after the admission
of the water, I was much amused with observing the large bubbles of the
newly generated air, which came through the quicksilver, the sudden
diminution of them when they came to the water, and the very small
bubbles which went through the water. They made, however, a continual,
though slow, increase of inflammable air.

Fixed air, being admitted to the whole produce of this air from copper,
had no sensible effect upon it. Upon the admission of water, a great
part of the mixture presently disappeared; another part, which I suppose
to have been the fixed air, was absorbed slowly; and in this particular
case the very small permanent residuum did not take fire; but it is
very possible that it might have done so, if the quantity had been
greater.

The solution of _lead_ in the marine acid is attended with the very same
phaenomena as the solution of copper in the same acid; about three
fourths of the generated air disappearing on the admission of water; and
the remainder being inflammable.

The solutions of iron, tin, and zinc, in the marine acid, were all
attended with the same phaenomena as the solutions of copper and lead,
but in a less degree; for in iron one eighth, in tin one sixth, and in
zinc one tenth of the generated air disappeared on the admission of
water. The remainder of the air from iron, in this case, burned with a
green, or very light blue flame.

I had always thought it something extraordinary that a species of air
should _lose its elasticity_ by the mere _contact_ of any thing, and
from the first suspected that it must have been _imbibed_ by the water
that was admitted to it; but so very great a quantity of this air
disappeared upon the admission of a very small quantity of water, that
at first I could not help concluding that appearances f