of spark, brush, and glow, 1533, 1539, 1542. ——­ of gases to positive and negative discharge, 1510. ——­ of neighbouring particles to each other, 619, 624. ——­ of elements in decomposing electrolytes, 923, 1702. ——­ ——­ exciting electrolytes, 921. ——­ of acids and bases voltaically, 927, 933.  Remarks on the active battery, 1034, 1136.  Residual charge of a Leyden jar, 1249. Resistance to electrolysis, 891, 904, 911, 1007. ——­ of an electrolyte to decomposition, 1007. Results of electrolysis, primary or secondary, 742, 777. ——­, practical, with the voltaic battery, 1136. ——­, general, as to induction, 1295, 1669.  Retention of electricity by pressure of the atmosphere explained, 1377,
  1398.
Revolving plate. See Arago’s phenomena. ——­ globe, Barlow’s, effect explained, 137, 160, 169. ——­ ——­, magnetic, 164. ——­ ——­, direction of currents in, 161, 166.  Riffault’s and Chompre’s theory of electro-chemical decomposition, 485,
  507, 512. 
Rock crystal, induction across, 1692.  Room, insulated and electrified, 1173.  Rotation of the earth a cause of magneto-electric induction, 181.

Salts considered as electrolytes, 698.  Scale of electrolytic intensities, 912. Secondary electrolytical results, 702, 742, 748, 777. ——­ become measures of the electric current, 843. Sections of the current, 498, 1634. ——­, decomposing force alike in all, 501, 1621. Sections of lines of inductive action, 1369. ——­, amount of force constant, 1369.  Shock, strong, with one voltaic pair, 1049. Silver, chloride of, its electrolyzation, 541, 813, 902. ——­, electrolytic intensity for, 979.  Silver, sulphuret of, hot, conducts well, 433. Simple voltaic circles, 875. ——­, decomposition effected by, 897, 904, 931.  Single and many pairs of plates, relation of, 990. Single voltaic circuits, 875. ——­ without metallic contact, 879. ——­ with metallic contact, 893. ——­ their force exalted, 906. ——­ give strong shocks, 1049. ——­ ——­ a bright spark, 1050. Solid electrolytes are non-conductors, 394, 402, 1358. ——­, why, 910, 1705. Solids, their power of inducing combination, 564, 618. ——­ interfered with, 638.  Solubility of gases in cases of electrolyzation, 717, 728. Source of electricity in the voltaic pile, 875. ——­ is chemical action, 879, 916, 919, 1741.  Spark, 1360, 1406. Spark, electric, its conditions, 1360, 1406, 1553. ——­ path, 1407. ——­ light, 1553. ——­ insensible duration or time, 1438. ——­ accompanying dark parts, 1547, 1632. ——­ determination, 1370. 1409. Spark is affected by the dielectrics, 1395, 1421. ——­ size of conductor, 1372. ——­ form of conductor, 1302, 1374. ——­ rarefaction of air, 1375. Spark, atmospheric or lightning, 1464, 1641. ——­, negative, 1393, 1467, 1482, 1484, 1502. ——­, positive, 1393, 1448, 1467, 1482, 1484, 1502. ——­, ragged, 1420, 1448. ——­, when not straight, why, 1568. ——­, variation in its length, 1381. ——­, tendency