Part 13 (1/2)
If the electrified person put his finger, or a rod of iron, into a dish containing warm spirits of wine, it will be immediately in a blaze; and if there be a wick or thread in the spirit, that communicates with a train of gunpowder, he may be made to blow up a magazine, or set a city on fire, with a piece of cold iron, and at the same time be ignorant of the mischief he is doing.
_The Inconceivable Shock._
Put in a person's hand a wire that is fixed on to the hook that comes from the chain, which communicates with one side of the battery, and in his other hand put a small wire with a hook at the end of it, which you direct him to fix on to a hook which comes from the other chain.
On attempting to do this, he will instantly receive a shock from his body, without being able to guess the cause.
Care should be taken that the shock be not too strong; and regard should be had to the const.i.tution and disposition of the party, as a shock that would hardly affect one person, might be productive of very serious consequences to another.
Much entertainment may be derived from concealing the chain that communicates with that which proceeds from the outside of the battery, under a carpet, and placing the wire that communicates with the chain from the inside, in such a manner that a person may put his hand on it without suspicion, at the same time that his feet are upon the other wire.
The whole company may be made to partake of the shock, by joining hands, and forming a circle. The experiment may also be varied if they tread upon each other's toes, or lay their hands upon each other's heads. It might happen, by the latter method, that the whole company would be struck to the ground; but it will be productive of no danger, and very little inconvenience; on the contrary, it has happened that they have neither heard nor felt the shock.
To exhibit the five following amus.e.m.e.nts in electricity, the room in which they are performed must be darkened.
_The Miraculous Luminaries._
You must previously prepare the following phosphorus: Calcine common oyster-sh.e.l.ls, by burning them in the fire for half an hour; then reduce them to powder; of the clearest of which take three parts, and of flowers of sulphur one part; put the mixture into a crucible, about an inch and a half deep. Let it burn in a strong fire for rather better than an hour; and when it is cool, turn it out and break it in pieces; and, taking those pieces into a dark place, sc.r.a.pe off the parts that s.h.i.+ne brightest, which, if good, will be a white powder.
Then construct a circular board, of three or four feet diameter, on the centre of which draw in gum-water, or any adhesive liquid, a half-moon, of three or four inches diameter, and a number of stars round it, at different distances, and of various magnitudes. Strew the phosphorus over the figures, to the thickness of about a quarter of an inch, laying one coat over the other. Place this board behind a curtain; and when you draw the curtain up or back, discharge one electrifying jar or phial over each figure, at the distance of about an inch, and they will become illuminated, exhibiting a very striking resemblance of the moon and stars; and will continue to s.h.i.+ne for about half an hour, their splendour becoming gradually more faint.
_The Fiery Shower._
On the plate put a number of any kind of seeds, grains of sand, or bra.s.s dust. The conductor being strongly electrified, those light particles will be attracted and repelled by the plate suspended from the conductor, with amazing rapidity, so as to exhibit a perfect fiery shower.
Another way is by a sponge that has been soaked in water. When this sponge is first hung to the conductor, the water will drop from it very slowly; but when it is electrified, the drops will fall very fast, and appear like small globes of fire, illuminating the basin into which they fall.
_The Illuminated Vacuum._
Take a tall receiver that is very dry, and fix through the top of it, with cement, a blunt wire; then exhaust the receiver, and present the k.n.o.b of the wire to the conductor, and every spark will pa.s.s through the vacuum in a broad stream of light, visible through the whole length of the receiver, let it be as tall as it will. This generally divides into a variety of beautiful rivulets, which are continually changing their course, uniting and dividing again in the most pleasing manner.
If a jar be discharged through this vacuum, it presents the appearance of a very dense body of fire, darting directly through the centre of the vacuum, without touching the sides; whereas, when a single spark pa.s.ses through, it generally goes more or less to the side, and a finger placed on the outside of the gla.s.s will draw it wherever a person pleases. If the vessel be grasped by both hands, every spark is felt like the pulsation of a large artery; and all the fire makes towards the hands. This pulsation is even felt at some distance from the receiver, and a light is seen between the hand and the gla.s.s.
All this while, the pointed wire is supposed to be electrified positively; if it be electrified negatively, the appearance is astonis.h.i.+ngly different; instead of streams of fire, nothing is seen but one uniform luminous appearance, like a white cloud, or the _milky way_ in a clear star-light night. It seldom reaches the whole length of the vessel, but generally appears only at the end of the wire, like a lucid ball.
If a small phial be inserted in the neck of a small receiver, so that the external surface of the gla.s.s be exposed to the vacuum, it will produce a very beautiful appearance. The phial must be coated on the inside; and while it is charging, at every spark taken from the conductor into the inside, a flash of light is seen to dart at the same time from every part of the external surface of the phial, so as to quite fill the receiver. Upon making the discharge, the light is seen to run in a much closer body, the whole coming out at once.
_The Illuminated Cylinder._
Provide a gla.s.s cylinder, three feet long, and three inches diameter; near the bottom of it fix a bra.s.s plate, and have another bra.s.s plate, so contrived that you may let it down the cylinder, and bring it as near the first plate as you desire. Let this cylinder be exhausted and insulated, and when the upper part is electrified, the electric matter will pa.s.s from one plate to the other, when they are at the greatest distance from each other that the cylinder will admit. The bra.s.s plate at the bottom of the cylinder will also be as strongly electrified as if it were connected by a wire to the prime conductor.
The electric matter, as it pa.s.ses through this vacuum, presents a most brilliant spectacle, exhibiting sparkling flashes of fire the whole length of the tube, and of a bright silver hue, representing the most lively exhalations of the aurora borealis.
_The Electric Aurora Borealis._