Inflammable Phosphorus
Take the meal of flour of any vegetable, put it into an iron pan over
a moderate fire, and keep it stirring with an iron spoon till it
changes to a black powder; to one part of this add four parts of raw
alum. Make the whole into a fine powder; put it again into the iron
pan, and keep stirring it till it almost catches fire, to prevent its
forming into lumps, as it is apt to do when the alum melts; in which
case it mus
be broken again, stirred about, and accurately mixed with
the flour, till it emits no more fumes, and the whole appears a fine
black powder.
Put this powder in a clean dry phial with a narrow neck, filling it to
about one-third of the top. Then stop the mouth of the phial with
loose paper, so as to let the air pass freely through it, and leave
room for the fumes to come through the neck. Place the phial in a
crucible, encompassed on all sides with sand, so that it may not touch
any part of the crucible, but a considerable space everywhere left
between. The phial must be covered up with sand, leaving only a small
part bare, by which you can discern whether the powder is ignited. In
this state, the crucible is to be surrounded with coals, kindled
slowly till it is well heated on all sides, and then the fire is to be
raised, till the crucible and every thing in it is red-hot; keep it in
this state an hour; after this, the fire still burning as fiercely,
close up the orifice of the phial with wax, to exclude the air. Leave
it to cool, and you will find in it a black dusty coal formed of the
flour and alum.
Shake a small quantity of this out of the phial into the cool air, and
it will immediately take fire, but will not burn any thing. Keep the
bottle dry, as even the air will spoil it effectually.