No. 2. A mass of matter melted and
run together, colored on the outside with
red and green. It consists of sulphur,
mixed with iron, copper, sand, and other kinds
of earth which contain some acid of salt.
If a piece of it is put into a moderate coal-
fire, and thoroughly heated, it gives a very
fine blue flame. Ten quintins of it were
made red-hot in the fire, pulverized, mixed
with an equal quantity of oil of vitriol, and
diluted, during the operation, with eight
parts of water. After some hours, the solution
was separated, and gave a fine copper-
color to a piece of polished iron. To this
solution was added as much iron as could
be dissolved, for the purpose of separating
the copper, which, on being afterwards
melted, was found to weigh fifteen grains.
This copper yielded readily to the hammer,
and with the addition of spirits of sal ammoniac
afforded a very bright blue color.
To the sediment, still undissolved, was again
added half as much vitriolic acid, and the
whole was treated in the same manner as
before. The solution was then precipitated
at blood heat, and afforded one quintin of
Prussian blue. The still remaining sedi*
ment, when dried, weighed eight quintins,
and consequently the acids had extracted
one quintin and forty-five grains of iron,
and fifteen grains of copper. The remaining
eight quintins, when melted down with
borax, gave a clear black glass, without re-
gulus.
No. 3. . A white kind of calcined earth,
one ounce in weight. I t caused an astringent
sensation upon the tongue. On being
put into boiling water, half a quintin of copper
vitriol'was extracted from it.
No. 4 was to all appearance nothing
but common lava, and, as far as could be
ascertained, consisted of sulphur ore mixed
with iron, a little copper, and various kinds
of earths, melted down together. The mineral
acids had no effect upon the lava, and,
on its being pulverized, a very small quantity
of iron only was produced. Four small
pieces, weighing three and a half quintins,
which appeared to be more light and
brittle than the rest, and totally free from
white spots, were melted down with borax,
when they yielded a lump of copper weighing
three and a half grains. Half a pound