y, and determined me to inquire
into the truth of them all by way of experiment. I therefore engaged
myself in a set of trials; the history of which is here subjoined. Some
new facts are likeways occasionally mentioned; and here it will be
proper to inform the reader, that I have never mentioned any without
satisfying myself of their truth by experiment, tho' I have sometimes
taken the liberty to neglect describing the experiments when they seemed
sufficiently obvious.

Desiring to know how much of an acid a calcarious earth will absorb, and
what quantity of air is expelled during the dissolution, I saturated two
drams of chalk with diluted spirit of salt, and used the Florentine
flask, as related in a similar experiment upon magnesia. Seven drams and
one grain of the acid finished the dissolution, and the chalk lost two
scruples and eight grains of air.

This experiment was necessary before the following, by which I proposed
to inquire into the truth of the first proposition so far as it relates
to quick-lime.

Two drams of chalk were converted into a perfect quick-lime, and lost
two scruples and twelve grains in the fire. This quick-lime was slaked
or reduced to a milky liquor with an ounce of water, and then dissolved
in the same manner, and with the same acid, as the two drams of chalk in
the preceding experiment. Six drams, two scruples and fourteen grains of
the acid finished the saturation without any sensible effervescence or
loss of weight.

It therefore appears from these experiments, that no air is separated
from quick-lime by an acid, and that chalk saturates nearly the same
quantity of acid after it is converted into quick-lime as before.

With respect to the second proposition, I tried the following
experiments.

A piece of perfect quick-lime made from two drams of chalk, and which
weighed one dram and eight grains, was reduced to a very fine powder,
and thrown into a filtrated mixture of an ounce of a fixed alkaline salt
and two ounces of water. After a slight digestion, the powder being well
washed and dried, weighed one dram and fifty eight grains. It was
similar in every trial to a fine powder of ordinary chalk, and was
therefore saturated with air which must have been furnished by the
alkali.

A dram of pure salt of tartar was dissolved in fourteen pounds of
lime-water, and the powder thereby precipitated, being carefully
collected and dried, weighed one and fifty grains. When exposed to a
v