current, 1631.  Inseparability of the two electric forces, 1163, 1177, 1244, 1628.  Insulating power of different gases, 1388, 1395, 1507. Insulation, 1320, 1359, 1361. ——­, its nature, 1321. ——­ is sustained induction, 1324. ——­, degree of induction sustained, 1362. ——­ dependent on the dielectrics, 1368. ——­ ——­ distance in air, 1303, 1364, 1371. ——­ ——­ density of air, 1365, 1375. ——­ ——­ induction, 1368. ——­ ——­ form of conductors, 1302, 1374. ——­, as affected by temperature of air, 1367, 1380. ——­ in different gases, 1381, 1388. ——­ ——­ differs, 1395. ——­ in liquids and solids, 1403. ——­ in metals, 1328, 1331, 1332. ——­ and conduction not essentially different, 1320, 1326, 1336, 1338,
  1561.
——­, its relation to induction, 1324, 1362, 1368, 1678. Insulators, liquid, good, 1172. ——­, solid, good, 1254. ——­, the best conduct, 1233, 1241, 1245, 1247, 1254. ——­ tested as to conduction, 1255. ——­ and conductors, relation of, 1328, 1334, 1338. Intensity, its influence in conduction, 419. ——­, inductive, how represented, 1370. ——­, relative, of magneto-electric currents, 183, 193, 211, 213. ——­ of disruptive discharge constant, 1410. ——­, electrolytic, 912, 966, 983, 1354. ——­ necessary for electrolyzation, 911, 966. ——­ of the current of single circles, 904. ——­ ——­ increased, 906. ——­ of electricity in the voltaic battery, 990, 993. ——­ of voltaic current increased, 906, 990. Interference with combining power of platina, 638, 655. ——­ by olefiant gas, 640. ——­ carbonic oxide, 645. ——­ sulphuret of carbon, 650. ——­ ether, 651.  Interpositions, their retarding effects, 1018. Iodides in solution, their electrolysis, 769. ——­ fusion, their electrolysis, 802, 813. Iodide of lead, electrolysed, 802, 818. ——­ of potassium, test of chemical action, 316. Ions, what, 665, 824, 833, 834, 849. ——­ not transferable alone, 542, 547, 826. ——­, table of, 847. Iron, both magnetic and magneto-electric at once, 138, 254. ——­, copper and sulphur circles, 943.

Jenkin, his shock by one pair of plates, 1049.

Kemp, his amalgam of zinc, 999. 
Knight, Dr. Gowin, his magnet, 44.

Lac, charge removed from, 1203. ——­, induction through, 1255. ——­, specific inductive capacity of, 1256, 1269. ——­, effects of its conducting power, 1234. ——­, its relation to conduction and insulation, 1324. Lateral direction of inductive forces of currents, 26, 1108. ——­ forces of the current, 1653, 1709. Law of conduction, new, 380, 394, 410. ——­ magneto-electric induction, 114. ——­ volta-electric induction, 26. Lead, chloride of, electrolysed, 794, 815. ——­, fluoride of, conducts well when heated, 1340. ——­, iodide of, electrolysed, 802, 818. ——­, oxide of, electrolysed, 797. Leyden jar, condition of its charge, 1682. ——­, its charge, nature of, 1300. ——­, its discharge, 1300. ——­, its residual charge, 1249. Light, polarized, passed across electrolytes,