——. See Plates of platina. Coal gas, brush in, 1460. ——­, dark discharge in, 1556. ——­, positive and negative brush in, 1476. ——­, positive and negative discharge in, 1515. ——­, spark in, 1422.  Colladon on magnetic force of common electricity, 289.  Collectors, magneto-electric, 86. Combination effected by metals, 564, 608. ——­ solids, 564, 618. ——­ poles of platina, 566. ——­ platina, 564, 568, 571, 590, 630. ——­ ——­, as plates, 569. ——­ ——­, as sponge, 609, 636. ——­ ——­, cause of, 590, 616, 625, 656. ——­ ——­, how, 630. ——­ ——­, interferences with, 638, 652, 655. ——­ ——­ retarded by olefiant gas, 640. ——­ ——­ ——­ carbonic oxide, 645, 652. ——­ ——­ ——­ sulphuret of carbon, 650. ——­ ——­ ——­ ether, 651. ——­ ——­ ——­ other substances, 649, 653, 654.  Comparison of voltaic batteries, 1126, 1146. Conditions, general, of voltaic decomposition, 669. ——­, new, of electro-chemical decomposition, 453. Conducting power measured by a magnet, 216. ——­ of solid electrolytes, 419. ——­ of water, constant, 984. Conduction, 418, 1320. ——­, its nature, 1320, 1326, 1611. ——­, of two kinds, 987. ——­, preceded by induction, 1329, 1332, 1338. ——­ and insulation, cases of the same kind, 1320, 1326, 1336, 1338, 1561. ——­, its relation to the intensity of the current conducted, 419. ——­ common to all bodies, 444, 449. ——­ by a vacuum, 1613. ——­ by lac, 1234, 1324. ——­ by sulphur, 1241, 1328. ——­ by glass, 1239, 1324. ——­ by spermaceti, 1240, 1323. ——­ by gases, 1336. ——­, slow, 1233, 1245, 1328. ——­ affected by temperature, 445, 1339. ——­ by metals diminished by heat, 432, 445. ——­ increased by heat, 432, 441, 445. ——­ of electricity and heat, relation of, 416. ——­, simple, can occur in electrolytes, 967, 983. ——­, ——­ with very feeble currents, 970. ——­ by electrolytes without decomposition, 968, 1017, 1032. ——­ and decomposition associated in electrolytes, 413, 676, 854. ——­ facilitated in electrolytes, 1355. ——­ by water bad, 1159. ——­ ——­ improved by dissolved bodies, 984, 1355. ——­, electrolytic, stopped, 380, 1358, 1705. ——­ of currents stopped by ice, 381. ——­ conferred by liquefaction, 394, 410. ——­ taken away by solidification, 394, 1705. ——­ ——­ why, 910, 1705. ——­, new law of, 380, 394, 410. ——­, ——­, supposed exception to, 691, 1340. ——­, general results as to, 443.  Conductive discharge, 1320. Conductors, electrolytic, 474. ——­, magneto-electric, 86. ——­, their nature does not affect the electric brush, 1454. ——­, size of, affects discharge, 1372. ——­, form of, affects discharge, 1374, 1425. ——­, distribution of electricity on, 1368. ——­, ——­, affected by form, 1374. ——­, ——­, ——­ distance, 1364, 1371. ——­, ——­, ——­ air pressure, 1375. ——­, ——­, irregular with equal pressure, 1378.  Constancy of electric current, 1618. Constitution of electrolytes as to proportions, 679, 697, 830, 1708. ——­ liquidity, 394, 823. Contact of metals not necessary for electrolyzation, 879.