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.