ie on his back, and his hair be tied behind. Into
each nostril put a conical piece of paper, open at each end to allow
of breathing. The face is to be lightly oiled over, and the plaster
being properly prepared is to be poured over the face, (taking care
that the eyes are shut,) till it is a quarter of an inch thick. In a
few minutes the plaster may be removed. In this a mould is to be
formed, from which a second cast is to be taken, that will furnish
casts exactly like the original.

_Curious Experiment with a Glass of Water._

Saturate a certain quantity of water in a moderate heat, with three
ounces of sugar; and when it will no longer receive that, there is
still room in it for two ounces of salt of tartar, and after that for
an ounce and a drachm of green vitriol, nearly six drachms of nitre,
the same of sal-ammoniac, two drachms and a scruple of alum, and a
drachm and half of borax.

_To make Artificial Coruscations._

There is a method of producing artificial coruscations, or sparkling
fiery meteors, which will be visible, not only in the dark but at
noon-day, and that from two liquors actually cold. The method is
this:--Fifteen grains of solid phosphorus are to be melted in about a
drachm of water: when this is cold, pour upon it two ounces of oil of
vitriol; let these be shaken together in a large phial, and they will
at first heat, and afterwards will throw up fiery balls in great
number, which will adhere like so many stars to the sides of the
glass, and continue burning a considerable time; after this, if a
small quantity of oil of turpentine be poured in without shaking the
phial, the mixture will of itself take fire, and burn very furiously.
The vessels should be large and open at the top.

_Another Method._

Artificial coruscations may also be produced by means of oil of
vitriol and iron, in the following manner:--Take a glass vessel
capable of holding three quarts: put into this three ounces of oil of
vitriol, and twelve ounces of water, then warming the mixture a
little, throw in at several times two ounces, or more, of clear iron
filings: upon this, an ebullition and white vapours will arise; then
present a lighted candle to the mouth of the vessel, and the vapour
will take fire, and afford a bright fulmination or flash; like
lightning. Applying the candle in this manner several times, the
effect will always be the same; and sometimes the fire will fill the
whole body of the glass, and ev