Chapter I: Ice-pail experiment of Faraday, 270

Identity of frictional and voltaic electricity, 266.

Induced currents, discovered by Faraday, 259;
explained by structure of ether, 304;
from earth's action, 262.

Induction coil, 320.

Induction, Franklin's experiments on, 90;
self, 142, 306.

Induction machines, principle of, 316.

Insulators for lightning-rods, 96.

Interference, principle of, discovered by Young, 208;
spectra of, obtained by Young, 225.

Invisible college, 13.

J.

Jenkin, William, discovery of the "extra current" by, 268.

Joule and Thomson's determination of the heat absorbed by air in
expanding, 324.

Joule, Dr., establishment of mechanical theory of heat by, 193, 324.

Joule's law, 324;
proof that heat and energy are equivalent, 324;
determination of the mechanical equivalent of heat, 325.

Junto Club, formation of the, 51.

K.

Kelland's, Professor, edition of Young's lectures, 212.

Kinnersley commences lecturing, 73.

Kite, Franklin's, 88.

Knobs _versus_ points, 95.