[ % ]

The ends of the wires on which the threads are placed inthis experiment* have each of them a brush, or a lucid pencilof ravs.

Experiment IV. in Magnetism.

Take the two needles, and put them in the water as in theformer experiment, with their north or south poles opposite, andthey will mutually repel each other.

Experiment V. in Electricity.

i To few, that when Hwo electrified bodies mutually repel each other ,they will either of them ^attraSi a light body suspended betweenthem. K.

Let the jars and the curved wires remain as in the third ex-periment. Take off the sockets with the threads from the endsof the wires m, and n, and put on two other sockets with brassballs, (lee plate I., fig. 15.) and let the balls be a little distancefrom each other. Turn the cylinder of the machine, and chargethe jars; the balls will be" electrified, and the electric effluvia ineach ball will mutually repel each other, (fee experiment III. fore-going.) Suspend a pith, or cork-ball between the two brassknobs, and they will either of them attract a light body placedbetween them. r :

Experiment VI. Afmilar experiment in Magnetsm.

Place either the north or the south poles of two magnets parallelto the horizon, and opposite 0 to each other, and let their dis-

K tance