tom, as soon as the Mouth
is uncorked._

Provide a tin vessel, two or three inches in diameter, and five or six
inches in height, having a mouth about three inches in width; and in
the bottom several small holes, just large enough to admit a small
needle. Plunge it in water with its mouth open, and when full, while
it remains in the water, stop it very closely. You can play a trick
with a person, by desiring him to uncork it; if he places it on his
knee for that purpose, the moment it is uncorked the water will run
through at the bottom, and make him completely wet.

_A Powder which catches Fire when exposed to the Air._

Put three ounces of rock alum, and one ounce of honey or sugar, into a
new earthen dish, glazed, and which is capable of standing a strong
heat; keep the mixture over the fire, stirring it continually till it
becomes very dry and hard; then remove it from the fire, and pound it
to a coarse powder. Put this powder into a long-necked bottle, leaving
a part of the vessel empty; and, having placed it in a crucible, fill
up the crucible with fine sand, and surround it with burning coals.
When the bottle has been kept at a red heat for about seven or eight
minutes, and no more vapour issues from it, remove it from the fire,
then stop it with a piece of cork; and, having suffered it to cool,
preserve the mixture in small bottles well closed.

If you unclose one of these bottles, and let fall a few grains of this
powder on a bit of paper, or any other very dry substance, it will
first become blue, then brown, and will at last burn the paper or
other dry substance on which it has fallen.

_Fulminating Gold._

Put into a small long-necked bottle, resting on a little sand, one
part of fine gold filings, and three parts of aqua regia,
(nitro-muriatic acid.) When the gold is dissolved, pour the solution
into a glass, and add five or six times the quantity of water. Then
take spirit of sal ammoniac or oil of tartar, and pour it drop by drop
into the solution, until the gold is entirely precipitated to the
bottom of the glass. Decant the liquor that swims at the top, by
inclining the glass; and, having washed it several times in warm
water, dry it at a moderate heat, placing it on paper capable of
absorbing all the moisture.

If a grain of this powder, put into a spoon, (it should be an iron
one,) be exposed to the flame of a candle, it will explode with a very
loud report.

_To melt a piece of Money