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, 17