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CONVERSATION XXXV.

Experiments made with the Electrical Battery.

TUTOR. I will now show you some experiments with this large battery. To perform these in perfect safety, I must beg you to stand a good distance from it: this will prevent accidents.

Example 1. I take this quire of writing. paper, and place it against the hook or wire that comes out of the box; and when the battery is charged I put one ball of the discharging-rod to a knob of one of the wires F, and bring the other knob to that part of the paper that stands against the wire, proceeding from the box. You see what a hole it has made through every sheet of the paper. Smell the paper where the perforation is.

Charles. It smells like sulphur.

Tutor. Or more like phosphorus. You observe, in this experiment, that the electric fluid passed from the inside of the jars through the conducting rod and paper, to the outside.

James. Why did it not pass through the paper,

in the same manner as it passed the brass discharging rod, in which it made no hole ?

Tutor. Paper is a non-conducting sabstance, but brass is a conductor: through the latter it passes without any resistance, and in its endeavour to get to the inside of the box, it burst the paper as you see.

The same thing would have happened had there been twice or thrice as

The electric fluid of a single jar will pierce through many sheets of paper.

VOL. III.

much paper.

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Charles. Would it serve any other non-conducting substance in the same manner?

Tutor. Yes, it will even break a thin piece of glass, or of resin, or of sealing. wax, if they be interposed between the discharging rod and the outside of the coating of the battery.

Example 2. Place a piece of loaf-sugar in the situation in which the quire of paper was just now, the

sugar will be broken, and in the dark it will appear beautifully illuminated, and remain so for many seconds of time.

Example 3. Let the small piece of wire, proceeding from the hole in the box, be laid on one side of a plate, containing some spirits of wine, and, on the opposite side of the plate, bring one of the knobs of the discharging-rod, while the other is carried to the wires connected with the inside of

the jars.

Charles. Then the electric fluid will have, a passage through the spirit ?

Tutor. It will set it on fire instantly.

Example 4. Take two slips of common window-glass, about four inches long, and one inch broad: put a slip of gold-leaf between the glasses, leaving a small part of it out at each end, then tie the glasses to. gether, or press them with a heavy weight, and send the charge of the battery through it, by connecting one end of the glass with the outside of the jars, and bringing the discharging-rod to the other end, and to the wires of the inside of the battery.

James. Will it break the glass?

Tutor. It probably will: but whether it does or not, the gold-leaf will be forced into the

pores

of the glass, so as to appear like glass stained with gold, which nothing can wash away.

Example 5. If the gold-leaf be put between two cards, and a strong charge passed through it, it will be completely fused or melted, the marks of which will appear on the card.

This instrument, (Plate vii. Fig. 11.) called an universal discharger, is very useful for passing charges through many substances. B B are glass pillars cemented into the frame A. To each of the pillars is cemented a brass cap, and a double joint for horizontal and vertical motions ; on the top of each joint is a spring tube, which holds the sliding wires c , C X, so that they may be set at various distances from each other, and turned in any direction ; the extremities of the wires are pointed, but with screws, at about half an inch from the points, to receive balls. The table E D, inlaid with a piece of ivory, is made to move up and down in a socket, and a screw fastens it to any required height. The rings c c are very convenient for fixing a chain or wire to them, which proceeds from the conductor.

Charles. Do you lay any thing on the ivory, between the balls, when you want to send the charge of a battery through it ?

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