eft open to admit the following composition.

Dissolve, by a slow fire, six ounces of hogs'-lard, with half an ounce
of white wax; to which you may add an ounce of clear linseed oil.

This must be poured in a liquid state, and before a fire, between the
glasses, by the space left in the sides, and which you are then to
close up. Wipe the glasses clean, and hold them before the fire, to
see that the composition will not run out at any part.

Then fasten with gum a picture or print, painted on very thin paper,
with its face to one of the glasses, and, if you like, you may fix the
whole in a frame.

While the mixture between the glasses is cold, the picture will be
quite concealed, but become transparent when held to the fire; and, as
the composition cools, it will gradually disappear.

_Artificial Lightning._

Provide a tin tube that is larger at one end than it is at the other,
and in which there are several holes. Fill this tube with powdered
resin; and when it is shook over the flame of a torch, the reflection
will produce the exact appearance of lightning.

_Artificial Thunder._

Mix two drachms of the filings of iron, with one ounce of concentrated
spirit of vitriol, in a strong bottle that holds about a quarter of a
pint; stop it close, and in a few minutes shake the bottle; then
taking out the cork, put a lighted candle near its mouth, which should
be a little inclined, and you will soon observe an inflammation arise
from the bottle, attended with a loud explosion.

To guard against the danger of the bottle bursting, the best way would
be to bury it in the ground, and apply the light to the mouth by means
of a taper fastened to the end of a long stick.

_Another way._

Mix three ounces of saltpetre, two ounces of salt of tartar, and two
ounces of sulphur; roll the mixture up into a ball, of which take a
quantity, about the size of a hazel-nut, and, placing it in a ladle or
shovel over the fire, the explosion will resemble a loud clap of
thunder.

You will produce a much more violent commotion if you double or treble
the quantity of the last experiment; suppose you put two or three
ounces of the mixture into the shovel. For fear of accidents, it
should not be done in the house, but by placing the shovel over a
chafing-dish of very hot coals, in the open air, standing a great
distance off.

Common prudence will dictate the necessity of using great care in the
above experiments, as an accident w