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 cand e 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 even circulate to the bottom of the

liquor; at others, it will only reach a little down its neck. The

great caution to be used in making this experiment, is the making the

vapour of a proper heat; for if made too cold few vapours will arise;

and, if made too hot, they will arise too fast, and will only take

fire in the neck of the glass, without any remarkable coruscation.