——­ with a magnet, 147. ——­, ——­ a single wire, 170. ——­, ——­ a revolving plate, 149. ——­, ——­ a revolving ball, 160. ——­, ——­ the earth, 173.  Test between magnetic and magneto-electric action, 215, 243. Theory of combination of gases by clean platina, 619, 626, 630, 656. ——­ electro-chemical decomposition, 477, 661, 1623, 1704. ——­ the voltaic apparatus, 875, 1741. ——­ static induction, 1165, 1231, 1295, 1666, 1667. ——­ disruptive discharge, 1368, 1406, 1434. ——­ Arago’s phenomena, 120. Thermo-electricity, its general characters, 349. ——­ identical with other electricities, 360. ——­, its evolution of heat, 349. ——­, magnetic, force, 349. ——­, physiological effects, 349. ——­, spark, 349.  Time, 59, 68, 124, 1248, 1328, 1346, 1418, 1431, 1436, 1439, 1612, 1641,
  1730.
Tin, iodide of, electrolysed, 804. ——­, protochloride, electrolysis of, definite, 789, 819. Torpedo, nature of its electric discharge, 359. ——­, its enormous amount of electric force, 359.  Transfer of elements and the current, their relation, 923, 962. Transference is simultaneous in opposite directions, 542, 828. ——­, uncombined bodies do not travel, 544, 546, 826. ——­ of elements, 454, 507, 539, 550, 826. ——­ ——­ across great intervals, 455, 468. ——­ ——­, its nature, 519, 525, 538, 549. ——­ of chemical force, 918.  Transverse forces of the current, 1653, 1709.  Travelling of charged particles, 1563.  Trough, voltaic. See Battery, voltaic. Turpentine, oil of, a good fluid insulator, 1172. ——­, its insulating power destroyed, 1571. ——­ charged, 1172. ——­, brush in, 1452, ——­, electric motions in, 1588, 1595, ——­, convective currents in, 1595, 1598.

Unipolarity, 1635.

Vacuum, its relation to electricity, 1613.  Vaporization, 657. Velocity of conduction in metals varied, 1333. ——­ the electric discharge, 1641, 1649. ——­ conductive and electrolytic discharge, difference of, 1650.  Vicinity of plates in voltaic battery, 1148.  Volta-electric induction, 26. Volta-electrometer, 704, 736. ——­, fluid decomposed in it, water, 706, 728, 732. ——­, forms of, 707, 734. ——­ tested for variation of electrodes, 714, 722. ——­ ——­ fluid within, 727. ——­ ——­ intensity, 723. ——­, strength of acid used in, 728,733. ——­, its indications by oxygen and hydrogen, 736. ——­, ——­ hydrogen, 734. ——­, ——­ oxygen, 735. ——­, how used, 737.  Voltameter, 704. Voltaic battery, its nature, 875, 989. ——­, remarks on, 1034, 1136. ——­, improved, 1001, 1119. ——­, practical results with, 1136. ——. See Battery, voltaic. Voltaic circles, simple, 875. ——­, decomposition by, 897.  Voltaic circles associated, or battery, 989. Voltaic circuit, relation of bodies in, 962. ——­, defined, 282, 511. ——­, origin of, 916, 1741. ——­, its direction, 663, 925, ——­, intensity increased, 905, 990. ——­, produced by oxidation of zinc, 919, 930. ——­ not due to combination of oxide and acid, 925, 933.