the admixture of a substance which it attracts
more strongly than it does that salt; such as spirit of wine; and
quick-lime itself may be separated from water upon the same principle;
for if that spirit is added to an equal quantity of lime-water, the
mixture becomes turbid and deposites a sediment, which, when separated
and dissolved again in distilled water, composes lime-water. We may
therefore refer the above _phaenomenon_, with respect to the ley, to the
same cause with these, and say, that the water did not dissolve the
lime, because it already contained a caustic alkali, for which it has a
superior attraction.

I also rendered the volatile alkali caustic, in order to examine what
change it suffered in the operation, and obtained an exceedingly
volatile and acrid spirit, which neither effervesced with acids, nor
altered in the least the transparency of lime-water; and, altho' very
strong, was lighter than water, and floated upon it like spirit of wine.

I next inquired into the truth of the fifth proposition, in the
following manner.

Two drams of epsom-salt were dissolved in a small quantity of water, and
thrown into two ounces of the caustic-ley; the mixture instantly became
thick, like a decoction of starch or barley, by the magnesia, which was
precipitated. I then added spirit of vitriol by degrees, until the
mixture became perfectly clear, or the whole of the magnesia was again
dissolved; which happened without any effervescence or emission of air.

Half an ounce of chalk was dissolved in spirit of salt, the quantity of
which was so adjusted, that the mixture was not acid in the least
degree; and the solution was thrown into twelve ounces of the caustic
ley; which quantity I found, by experiment, to be sufficient for
precipitating almost the whole of the chalk. I now filtrated this turbid
liquor, and laid the powder remaining in the paper upon a chalk-stone,
in order to draw as much of the water from it as possible, and thereby
reduce it to the form of a more dense and heavy powder, that it might
subside the more perfectly in the following part of the experiment. I
then mixed it with about twenty ounces of pure water in a flask, and,
after allowing the powder to subside, poured off the water, which had
all the qualities of lime-water. And I successively converted eight
waters more into lime-water, seven of these in the same quantity, and
with the same management, as the first. The eighth was likeways in th