Index

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N.B. A dash rule represents the italics immediately preceding it. The references are sometimes to the individual paragraph, and sometimes to that in conjunction with those which follow.

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Absolute charge of matter, 1169. ---- quantity of electricity in matter, 852, 861, 873. Acetate of potassa, its electrolysis, 749. Acetates, their electrolysis, 774. Acetic acid, its electrolysis, 773. Acid, nitric, formed in air by a spark, 324. ----, or alkali, alike in exciting the pile, 932. ----, transference of, 525. ---- for battery, its nature and strength, 1128, 1137. ---- ----, nitric, the best, 1138. ---- ----, effect of different strengths, 1139. ---- in voltaic pile, does not evolve the electricity, 925, 933. ---- ----, its use, 925. Acids and bases, their relation in the voltaic pile, 927, 933. Active battery, general remarks on, 1034, 1136. Adhesion of fluids to metals, 1038. Advantages of a new voltaic battery, 1132. Affinities, chemical, opposed voltaically, 891, 904, 910. ----, their relation in the active pile, 949. Air, its attraction by surfaces, 622. ----, charge of, 1173. ----, ----, by brush, 1434, 1441. ----, ----, by glow, 1537, 1543. ----, convective currents in, 1572, 1576, 1581. ----, dark discharge in, 1548. ----, disruptive discharge in, 1359, 1406, 1425, 1526. ----, induction in, 1208, 1215, 1284, 1362. ----, its insulating and conducting power, 411, 1332, 1336, 1362. ----, its rarefaction facilitates discharge, 1375. ----, electrified, 1443. ----, electro-chemical decompositions in, 454, 1623. ----, hot, discharges voltaic battery, 271, 274. ----, poles of, 455, 461, 559. ----, positive and negative brush in, 1467, 1472, 1476. ----, ---- glow in, 1526, 1530. ----, ---- spark in, 1485. ----, rarefied, brush in, 1451, 1456. ----, retention of electricity on conductors by, 1377, 1398. ----, specific inductive capacity of, 1284. ----, ----, not varied by temperature or pressure, 1287, 1288. Alkali has strong exciting power in voltaic pile, 884, 931, 941. ----, transference of, 525. Amalgamated zinc, its condition, 1000. ----, how prepared, 863. ----, its valuable use, 863, 999. ---- battery, 1001. Ammonia, nature of its electrolysis, 748. ----, solution of, a bad conductor, 554, 748. Ampere's inductive results, 78, 255, 379 note. Anions defined, 665, 824. ----, table of, 847. ---- related through the entire circuit, 963. ----, their action in the voltaic pile, 924. ----, their direction of transfer, 962, Anode defined, 663. Antimony, its relation to magneto-electric induction, 139. ----, chloride of, not an electrolyte, 690, 796. ----, oxide of, how affected by the electric current, 801. ---- supposed new protoxide, 693. ---- ----, sulphuret, 694. Animal electricity, its general characters considered, 351. ---- is identical with other electricities, 354, 360. ----, its chemical force, 355. ----, enormous amount, 359. ----, evolution of heat, 353, ----, magnetic force, 351. ----, physiological effects, 357. ----, spark, 358. ----, tension, 352.

Apparatus, inductive, 1187. See Inductive apparatus. Arago's magnetic phenomena, their nature, 81, 120. ----, reason why no effect if no motion, 126, ----, direction of motion accounted for, 121. ----, due to induced electric currents, 119, 248. ----, like electro-magnetic rotations in principle, 121. ----, not due to direct induction of magnetism, 128, 138, 215, 243, 248. ----, obtained with electro-magnets, 129. ----, produced by conductors only, 130, 215. ----, time an element in, 124. ----, Babbage and Hershel's results explained, 127. Arago's experiment, Sturgeon's form of, 219. Associated voltaic circles, 989. Atmospheric balls of fire, 1611. ----, electricity, its chemical action, 336. Atomic number judged of from electrochemical equivalent, 851. Atoms of matter, 869, 1703. ----, their electric power, 856, 860. Attraction of particles, its influence in Doebereiner's phenomena, 619. Attractions, electric, their force, 1022 note. ----, chemic, produce current force, 852, 918, 947, 996, 1741. ----, ---- local force, 852, 921, 947, 959, 1739. ----, hygrometric, 621. Aurora borealis referred to magneto-electric induction, 192. Axis of power, the electric current on, 517, 1627, 1642.

Balls of fire, atmospheric, 1611. Barlow's revolving globe, magnetic effects explained, 137, 160. Barry, decomposed bodies by atmospheric electricity, 338. Bases and acids, their relation in the pile, 927. Battery, Leyden, that generally used, 291. Battery, voltaic, its nature, 856, 989. ----, origin of its power, 878, 989. ----, ---- not in contact, 887, 915, ----, ---- chemical, 879, 916, 919, 1741. ----, ----, oxidation of the zinc, 919, 944. ----, its circulating force, 858, 1120. ----, its local force, 1120. ----, quantity of electricity circulating, 990. ----, intensity of electricity circulating, 990, 993. ----, intensity of its current, 909, 994. ----, ---- increased, 905, 989. ----, its diminution in power, 1035. ----, ---- from adhesion of fluid, 1003, 1136. ----, ---- ---- peculiar state of metal, 1040. ----, ---- ---- exhaustion of charge, 1042. ----, ---- ---- irregularity of plates, 1045, 1146. ----, use of metallic contact in, 893, 896. ----, electrolytes essential to it, 921. ----, ----, why, 858, 923. ----, state of metal and electrolyte before contact, 916. ----, conspiring action of associated affinities, 989. ----, purity of its zinc, 1144. ----, use of amalgamated zinc in, 999. ----, plates, their number, 1151. ----, ---- size, 1154. ----, ---- vicinity, 1148. ----, ---- immersion, 1150. ----, ---- relative age, 1146. ----, ---- foulness, 1145. ----, excited by acid, 880, 926, 1137. ----, ---- alkali, 931, 934, 941. ----, ---- sulphuretted solutions, 943. ----, the acid, its use, 925, ----, acid for, 1128, 1137. ----, nitric acid best for, 1137. ----, construction of, 989, 1001, 1121. ----, with numerous alternations, 989. ----, Hare's, 1123. ----, general remarks on, 1031. 1136. ----, simultaneous decompositions with, 1156. ----, practical results with, 1136. ----, improved, 1001, 1006, 1120. ----, ----, its construction, 1124. ----, ----, power, 1125, 1128. ----, ----, advantages, 1132. ----, ----, disadvantages, 1132. Batteries, voltaic, compared, 1126. Becquerel, his important secondary results, 745, 784. Berzelius, his view of combustion, 870, 959. Biot's theory of electro-chemical decomposition, 486. Bismuth, its relation to magneto-electric induction, 139. Bodies classed in relation to the electric current, 823. ---- classed in relation to magnetism, 255. Bodies electrolyzable, 824. Bonijol decomposed substances by atmospheric electricity, 336.

Boracic acid a bad conductor, 408. Brush, electric, 1425. ----, produced, 1425. ----, not affected by nature of conductors, 1454, 1473. ----, is affected by the dielectrics, 1455, 1463, 1475. ----, not dependent on current of air, 1440. ----, proves molecular action of dielectric, 1449, 1450. ----, its analysis, 1427, 1433. ----, nature, 1434, 1441, 1447. ----, form, 1428, 1449, 1451. ----, ramifications, 1439. ---- ----, their coalescence, 1453. ----, sound, 1426, 1431. ----, requisite intensity for, 1446. ---- has sensible duration, 1437. ---- is intermitting, 1427, 1431, 1451. ----, light of, 1444, 1445, 1451. ----, ----, in different gases, 1446, 1454. ----, dark? 1444, 1552. ----, passes into spark, 1448. ----, spark and glow relation of, 1533, 1539, 1542. ----, in gases, 1454, 1463, 1476. ----, oxygen, 1457, 1476. ----, nitrogen, 1458, 1476. ----, hydrogen, 1459, 1476. ----, coal-gas, 1460, 1476. ----, carbonic acid gas, 1461, 1476. ----, muriatic acid gas, 1462, 1476. ----, rare air, 1451, 1455, 1474. ----, oil of turpentine, 1452. ----, positive, 1455, 1467, 1484. ----, negative, 1468, 1472, 1484. ----, ----, of rapid recurrence, 1468, 1491. ----, positive and negative in different gases, 1455, 1475, 1506.

Capacity, specific inductive, 1252. ----. See Specific inductive capacity. Carbonic acid gas facilitates formation of spark, 1463. ----, brush in, 1461, 1476. ----, glow in, 1534. ----, spark in, 1422, 1463. ----, positive and negative brush in, 1476. ----, ---- discharge in, 1546. ----, non-interference of, 645, 652. Carbonic oxide gas, interference of, 645, 652. Carrying discharge, 1562. ----. See Discharge convective. Cathode described, 663, 824. Cations, or cathions, described, 665, 824. ----, table of, 817. ----, direction of their transfer, 962. Cations, are in relation through the entire circuit, 963. Characters of electricity, table of, 360. ---- the electric current, constant, 1618, 1627. ---- voltaic electricity, 268. ---- ordinary electricity, 284. ---- magneto-electricity, 343. ---- thermo-electricity, 349. ---- animal electricity, 351. Charge, free, 1684. ---- is always induction, 1171, 1177, 1300, 1682. ---- on surface of conductors: why, 1301. ----. influence of form on, 1302. ----, ---- distance on, 1303. ----, loss of, by convection, 1569. ----, removed from good insulators, 1203. ---- of matter, absolute, 1169. ---- of air, 1173. ---- ---- by brush, 1434, 1441. ---- ---- by glow, 1526, 1537, 1543. ---- of particles in air, 1564. ---- of oil of turpentine, 1172. ---- of inductive apparatus divided, 1208. ----, residual, of a Leyden jar, 1249. ----, chemical, for battery, good, 1137. -----, ----, weak and exhausted, 1042, 1143. Chemical action, the, exciting the pile is oxidation, 921. ---- superinduced by metals, 564. ---- ---- platina, 564, 617, 630. ---- tested by iodide of potassium, 315. Chemical actions, distant, opposed to each other, 891, 910, 1007. Chemical affinity influenced by mechanical forces, 656. ---- transferable through metals, 918. ---- statical or local, 852, 921, 917, 959. ---- current, 852, 918, 947, 996. Chemical decomposition by voltaic electricity, 278, 450, 661. ---- common electricity, 309, 453. ---- magneto-electricity, 346. ---- thermo-electricity, 349. ---- animal electricity, 355. ----. See Decomposition electro-chemical. Chemical and electrical forces identical, 877, 918, 947, 960, 965, 1031. Chloride of antimony not an electrolyte, 690. ---- lead, its electrolysis, 794, 815. ---- ----, electrolytic intensity for, 978. ---- silver, its electrolysis, 541, 813, 902. ---- ----, electrolytic intensity for, 979. ---- tin, its electrolysis, 789, 819. Chlorides in solution, their electrolysis, 766. ---- fusion, their electrolysis, 789, 813. Circle of anions and cathions, 963. Circles, simple voltaic, 875. ----, associated voltaic, 989. Circuit, voltaic, relation of bodies in, 962. Classification of bodies in relation to magnetism, 255. ---- the electric current, 823, 817. Cleanliness of metals and other solids, 633. Clean platina, its characters, 633, 717. ----, its power of effecting combination, 590, 605, 617, 632. ----, ----. 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. ----, its use in the voltaic battery, 893. ---- not necessary for spark, 915, 956. Contiguous particles, their relation to induction, 1165, 1679. ---- active in electrolysis, 1349, 1703. Convection, 1562, 1642. ---- or convective discharge. See Discharge convective. Copper, iron, and sulphur circle, 943. Coruscations of lightning, 1464. Coulomb's electrometer, 1180. ----, precautions in its use, 1182, 1186, 1206. Crystals, induction through, 1689. Cube, large, electrified, 1173.

Cubes of crystals, induction through, 1692, 1695. Current chemical affinity, 852, 918, 947, 996. Current, voltaic, without metallic contact, 879, 887. Current, electric, 1617. ----, defined, 282, 511. ----, nature of, 511, 667, 1617, 1627. ----, variously produced, 1618. ----, produced by chemical action, 879, 916, 1741. ----, ---- animals, 351. ----, ---- friction, 301, 307, 311. ----, ---- heat, 349, ----, ---- discharge of static electricity, 296, 307, 363. ----, ---- induction by other currents, 6, 1089. ----, ---- ---- magnets, 30, 88, 344. ----, evolved in the moving earth, 181. ----, in the earth, 187. ----, natural standard of direction, 663. ----, none of one electricity, 1627, 1632, 1635. ----, two forces everywhere in it, 1627, 1632, 1635, 1642. ----, one, and indivisible, 1627. ----, an axis of power, 517, 1642. ----, constant in its characters, 1618, 1627. ----, inexhaustibility of, 1631. ----, its velocity in conduction, 1648. ----, ---- electrolyzation, 1651. ----, regulated by a fine wire, 853, note. ----, affected by heat, 1637. ----, stopped by solidification, 381. ----, its section, 498, 504, 1634. ----, ---- presents a constant force, 1634. ----, produces chemical phenomena, 1621. ----, ---- heat, 1625. ----, its heating power uniform, 1630. ----, produces magnetism, 1653. ----, Porrett's effects produced by, 1646. ----, induction of, 1, 6, 232, 241, 1101, 1048. ----, ----, on itself, 1048. ----, ----. See Induction of electric current. ----, its inductive force lateral, 1108. ----, induced in different metals, 193, 213, 201, 211. ----, its transverse effects, 1653. ----, ---- constant, 1655. ----, its transverse forces, 1658. ----, ---- are in relation to contiguous particles, 1664. ----, ---- their polarity of character, 1665. ---- and magnet, their relation remembered, 38, note. Currents in air by convection, 1572, 1581. ----, metals by convection, 1603. ----, oil of turpentine by convection, 1595, 1598. Curved lines, induction in, 1215. Curves, magnetic, their relation to dynamic induction, 217, 232.

Daniell on the size of the voltaic metals, 1525. Dark discharge,1444, 1544. ----. See Discharge, dark.

Dates of some facts and publications, 139, note after. Davy's theory of electro-chemical decomposition, 482, 500. ---- electro-chemical views, 965. ---- mercurial cones, convective phenomena, 1603. Decomposing force alike in every section of the current, 501, 505. ----, variation of, on each particle, 503. Decomposition and conduction associated in electrolytes, 413, 854. ----, primary and secondary results of, 742, 777. ---- by common electricity, 309, 454. ---- ----, precautions, 322. Decomposition, electro-chemical, 450, 669. ----, nomenclature of, 661. ----, new terms relating to, 662. ----, its distinguishing character, 309. ----, by common electricity, 309, 454. ----, by a single pair of plates, 862, 897, 904, 931. ----, by the electric current, 1621. ----, without metallic contact, 880, 882. ----, its cause, 891, 904, 910. ----, not due to direct attraction or repulsion of poles, 493, 497, 536, 542, 5460. ----, dependent on previous induction, 1345. ----, ---- the electric current, 493, 510, 524, 854. ----, ---- intensity of current, 905. ----, ---- chemical affinity of particles, 519, 525, 519. ----, resistance to, 891, 910, 1007. ----, intensity requisite for, 966, 1354. ----, stopped by solidification, 380, 1358, 1705. ----, retarded by interpositions, 1007. ----, assisted by dissolved bodies, 1355. ----, division of the electrolyte, 1347, 1623, 1701. ----, transference, 519, 525, 538, 550, 1347, 1706. ----, why elements appear at the poles, 535. ----, uncombined bodies do not travel, 544, 546. ----, circular series of effects, 562, 962. ----, simultaneous, 1156, ----, definite, 329, 372, 377, 504, 704, 714, 722, 726, 732, 764, 783, 807, 821, 960. ----, ---- independent of variations of electrodes, 714, 722, 807, 832. ----, necessary intensity of current, 911, 966, 1345, 1354. ----, influence of water in, 472. ----, in air, 451, 461, 469. ----, some general conditions of, 669. ----, new conditions of, 453. ----, primary results, 742. ----, secondary results, 702, 742, 748, 777. ----, of acetates, 774. ----, acetic acid, 773. ----, ammonia, 748. ----, chloride of antimony, 690, 796. ----, ---- lead, 794, 815. ----, ---- silver, 541, 813, 979. ----, chlorides in solution, 766. ----, ---- fusion, 789, 913. ----, fused electrolytes, 789. ----, hydriodic acid and iodides, 767, 787. ----, hydrocyanic acid and cyanides, 771. ----, hydrofluoric acid and fluorides, 770. ----, iodide of lead, 802, 818. ----, ---- potassium, 805. ----, muriatic acid, 758, 780. ----, nitre, 753. ----, nitric acid, 752. ----, oxide antimony, 801. ----, ---- lead, 797. ----, protochloride of tin, 789, 819. ----, protiodide of tin, 804. ----, sugar, gum, &c., 776. ----, of sulphate of magnesia, 495. ----, sulphuric acid, 757. ----, sulphurous acid, 755. ----, tartaric acid, 775. ----, water, 704, 785, 807. ----, theory of, 477, 1345. ----, ----, by A. de la Rive, 489, 507, 514, 543. ----, ----, Biot, 486. ----, ----, Davy, 482, 500. ----, ----, Grotthuss, 481, 499, 515. ----, ----, Hachette, 491, 513, ----, ----, Riffault and Chompre, 485, 507, 512. ----, author's theory, 518, 524, 1345, 1623, 1703, 1766. Definite decomposing action of electricity, 329, 372, 377, 504, 704, 783, 821. ----, magnetic action of electricity, 216, 362, 367, 377. ----, electro-chemical action, 822, 869, 960. ----, ----, general principles of, 822, 862. ----, ----, in chloride of lead, 815. ----, ----, ---- silver, 813. ----, ----, in hydriodic acid, 767, 787. ----, ----, iodide of lead, 802, 818. ----, ----, muriatic acid, 758, 786, ----, ----, protochloride of tin, 819. ----, ----, water, 732, 785, 807.

Degree in measuring electricity, proposal for, 736. De la Rive on heat at the electrodes, 1637. ----, his theory of electro-chemical decomposition, 489, 507, 514, 543. Dielectrics, what, 1168. ----, their importance in electrical actions, 1666. ----, their relation to static induction, 1296. ----, their condition under induction, 1369, 1679. ----, their nature affects the brush, 1455. ----, their specific electric actions, 1296, 1398, 1423, 1454, 1503, 1560. Difference of positive and negative discharge, 1465, 1480, 1485. Differential inductometer, 1307. Direction of ions in the circuit, 962. ----, the electric current, 563. ----, the magneto-electric current, 114, 116. ----, the induced volta-electric current, 19, 26, 1091.

Disruptive discharge, 1359, 1405. See Discharge, disruptive. Discharge, electric, as balls of fire, 1641. ----, of Leyden jar, 1300. ----, of voltaic battery by hot air, 271, 274. ----, ---- points, 272. ----, velocity of, in metal, varied, 1333. ----, varieties of, 1319. ----, brush, 1425. See Brush. ----, carrying, 1562. See Discharge, convective. ----, conductive, 1320. See Conduction. ----, dark, 1444, 1544. ----, disruptive, 1359, 1405. ----, electrolytic, 1343, 1622, 1704. ----, glow, 1526. See Glow. ----, positive and negative, 1465. ----, spark, 1406. See Spark, electric. Discharge, connective, 1442, 1562, 1601, 1623, 1633, 1642. ----, in insulating media, 1562, 1572. ----, in good conductors, 1603. ----, with fluid terminations in air, 1581, 1589. ----, ---- liquids, 1597. ----, from a ball, 1576, 1590. ----, influence of points in, 1573. ----, affected by mechanical causes, 1579. ----, ---- flame, 1580. ----, with glow, 1576. ----, charge of a particle in air, 1564. ----, ---- oil of turpentine, 1570. ----, charge of air by, 1442, 1592. ----, currents produced in air, 1572, 1581, 1591. ----, ---- oil of turpentine, 1595, 1598. ----, direction of the currents, 1599, 1645. ----, Porrett's effects, 1646, ----, positive and negative, 1593, 1600, 1643. ----, related to electrolytic discharge, 1622, 1633. Discharge, dark, 1444, 1544, 1560. ----, with negative glow, 1544. ----, between positive and negative glow, 1547. ----, in air, 1548. ----, muriatic acid gas, 1554. ----, coal gas, 1556. ----, hydrogen, 1558. ----, nitrogen, 1559. Discharge, disruptive, 1405. ----, preceded by induction, 1362. ----, determined by one particle, 1370, 1409. ----, necessary intensity, 1409, 1553. ----, determining intensity constant, 1410. ----, related to particular dielectric, 1503. ----, facilitates like action, 1417, 1435, 1453, 1553. ----, its time, 1418, 1436, 1498, 1641. ----, varied by form of conductors, 1302, 1372, 1374. ----, ---- change in the dielectric, 1395, 1422,1454. ----, ---- rarefaction of air, 1365, 1375, 1451. ----, ---- temperature, 1367, 1380. ----, ---- distance of conductors, 1303, 1364, 1371. ----, ---- size of conductors, 1372. ----, in liquids and solids, 1403. ----, in different gases, 1381, 1388, 1421. ----, ---- not alike, 1395. ----, ---- specific differences, 1399, 1422, 1687. ----, positive and negative, 1393, 1399, 1465, 1524. ----, ----, distinctions, 1467, 1475, 1482. ----, ----, differences, 1485, 1501. ----, ----, relative facility, 1496, 1520. ----, ----, dependent on the dielectric, 1503. ----, ----, in different gases, 1506, 1510, 1518, 1687. ----, ----, of voltaic current, 1524. ----, brush, 1425. ----, collateral, 1412. ----, dark, 1444, 1544, 1560. ----, glow, 1526. ----, spark, 1406. ----, theory of, 1308, 1406, 1434. Discharge, electrolytic, 1164, 1343, 1621, 1703, 1706. ----, previous induction, 1345, 1351. ----, necessary intensity, 912, 966, 1346, 1354. ----, division of the electrolyte, 1347, 1704. ----, stopped by solidifying the electrolyte, 380, 1358, 1705. ----, facilitated by added bodies, 1355. ----, in curved lines, 521, 1216, 1351. ----, proves action of contiguous particles, 1349. ----, positive and negative, 1525. ----, velocity of electric current in, 1650. ----, related to convective discharge, 1622. ----, theory of, 1344, 1622, 1704.

Discharging train generally used, 292. Disruptive discharge, 1405. See Discharge, disruptive. Dissimulated electricity, 1684. Distance, its influence in induction, 1303, 1364,1371. ---- over disruptive discharge, 1364, 1371. Distant chemical actions, connected and opposed, 891, 909. Distinction of magnetic and magneto-electric action, 138, 215, 243, 253. Division of a charge by inductive apparatus, 1208. Doebereiner on combination effected by platina, 609, 610. Dulong and Thenard on combination by platina and solids, 609, 611. Dust, charge of its particles, 1567.

Earth, natural magneto-electric induction in, 181, 190, 192. Elasticity of gases, 626. ---- gaseous particles, 658. Electric brush, 1425. See Brush, electric. ---- condition of particles of matter, 862, 1669. ---- conduction, 1320. See Conduction. ---- current defined, 283, 511. ---- ----, nature of, 511, 1617, 1627. ---- ----. See Current, electric. ---- ----, induction of, 6, 232, 241, 1048, 1101. See Induction of electric current. ---- ----, ----, on itself, 1048. ---- discharge, 1319. See Discharge. ---- force, nature of, 1667. See Forces. ---- induction, 1162. See Induction. ---- inductive capacity, 1252. See Specific inductive capacity. ---- polarity, 1685. See Polarity, electric. ---- spark, 1406. See Spark, electric. ---- and magnetic forces, their relation, 118, 1411, 1653, 1658, 1709, 1731.

Electrics, charge of, 1171, 1247. Electrical excitation, 1737. See Excitation. ---- machine generally used, 290. ---- battery generally used, 291. ---- and chemical forces identical, 877, 917, 947, 960, 965, 1031. Electricities, their identity, however excited, 265, 360. ----, one or two, 516, 1667. ----, two, 1163. ----, ----, their independent existence, 1168. ----, ----, their inseparability, 1168, 1177, 1244. ----, ----, never separated in the current, 1628. Electricity, quantity of, in matter, 852, 861. ----, its distribution on conductors, 1368. ----, ---- influenced by form, 1302, 1374. ----, ---- ---- distance, 1303, 1364, 1371. ----, ---- ---- air's pressure, 1375. ----, relation of a vacuum to, 1613. ----, dissimulated, 1684. ----, common and voltaic, measured, 361, 860. ----, its definite decomposing action, 329, 377, 783, 1621. ----, ---- heating action, 1625. ----, ---- magnetic action, 216, 366. ----, animal, its characters, 351. ----, magneto-, its characters, 343. ----, ordinary, its characters, 284. ----, thermo-, its characters, 349. ----, voltaic, its characters, 268. Electricity from magnetism, 27, 36, 57, 83, 135, 140. ----, on magnetisation of soft iron by currents, 27, 34, 57, 113. ---- ---- magnets, 36, 44. ----, employing permanent magnets, 39, 84, 112. ----, ---- terrestrial magnetic force, 140, 150, 161. ----, ---- moving conductors, 55, 83, 132, 139, 149, 161, 171. ----, ---- ---- essential condition, 217. ---- by revolving plate, 83, 149, 240. ---- ---- a constant source of electricity, 89, 90, 154. ---- ----, law of evolution, 114. ---- ----, direction of the current evolved, 91, 99, 110, 116, 117. ---- ----, course of the currents in the plate, 123, 150. ---- by a revolving globe, 137, 160. ---- by plates, 94, 101. ---- by a wire, 49, 55, 109, 112, 137. ----, conductors and magnet may move together, 218. ----, current produced in a single wire, 49, 55, 170. ----, ---- a ready source of electricity, 46, note. ----, ---- momentary, 28, 30, 47. ----, ---- permanent, 89, 154. ----, ---- deflects galvanometer, 30, 39, 46. ----, ---- makes magnets, 34. ----, ----, shock of, 56. ----, ----, spark of, 32. ----, ---- traverses fluids, 23, 33. ----, ----, its direction, 30, 38, 41, 52, 53, 54, 78, 91, 99, 114, 142, 166, 220, 222. ----, effect of approximation and recession, 18, 39, 50. ----, the essential condition, 217. ----, general expression of the effects, 256. ----, from magnets alone, 220. Electricity of the voltaic pile, 875. ---- its source, 875. ---- ---- not metallic contact, 887, 915. ---- ---- is in chemical action, 879, 916, 919, 1738, 1741. Electro-chemical decomposition, 450, 661. ----, nomenclature, 661. ----, general conditions of, 669. ----, new conditions of, 453, ----, influence of water in, 472. ----, primary and secondary results, 742. ----, definite, 732, 783. ----, theory of, 477. ----. See also Decomposition, electrochemical. Electro-chemical equivalents, 824, 833, 835, 855. ----, table of, 847. ----, how ascertained, 837. ---- always consistent, 835. ---- same as chemical equivalents, 836, 839. ---- able to determine atomic number, 851.

Electro-chemical excitation, 878, 919, 1738. Electrode defined, 662. Electrodes affected by heat, 1637. ----, varied in size, 714, 722. ----, ---- nature, 807. ----. See Poles. Electrolysis, resistance to, 1007. Electrolyte defined, 664. ---- exciting, solution of acid, 881, 925. ---- ---- alkali, 931, 941. ---- exciting, water, 944, 945. ---- ---- sulphuretted solution, 943. Electrolytes, their necessary constitution, 669, 823, 829, 858, 921, 1347, 1708. ---- consist of single proportionals of elements, 679, 697, 830, 1707. ---- essential to voltaic pile, 921. ---- ----, why, 858, 923. ---- conduct and decompose simultaneously, 413. ---- can conduct feeble currents without decomposition, 967. ----, as ordinary conductors, 970, 983, 1344. ----, solid, their insulating and conducting power, 419. ----, real conductive power not affected by dissolved matters, 1356. ----, needful conducting power, 1158. ---- are good conductors when fluid, 394, 823. Electrolytes non-conductors when solid 381, 394. ----, why, 910, 1705. ----, the exception, 1032. Electrolytes, their particles polarize as wholes, 1700. ----, polarized light sent across, 951. ----, relation of their moving elements to the passing current, 923, 1704. ----, their resistance to decomposition, 891, 1007, 1705. ----, and metal, their states in the voltaic pile, 946. ----, salts considered as, 698. ----, acids not of this class, 681. Electrolytic action of the current, 478, 518, 1620. ---- conductors, 474. ---- discharge, 1343. See Discharge, electrolytic. ---- induction, 1164, 1343. ---- intensity, 911, 966, 983. ---- ---- varies for different bodies, 912, 986, 1354. ---- ---- of chloride of lead, 978. ---- ---- chloride of silver, 979. ---- ---- sulphate of soda, 975. ---- ---- water, 968, 981. ---- ---- its natural relation, 987. Electrolyzation, 450, 661, 1164, 1347, 1704. See Decomposition electro-chemical. ---- defined, 664. ---- facilitated, 394, 417, 549, 1355. ---- in a single circuit, 863, 879. ----, intensity needful for, 919, 966, ---- of chloride of silver, 541, 979. ---- sulphate of magnesia, 495. ---- and conduction associated, 413, 676. Electro-magnet, inductive effects in, 1060. Electro-magnetic induction definite, 216, 366. Electrometer, Coulomb's, described, 1180. ----, how used, 1183. Electro-tonic state, 60, 231, 242, 1114, 1661, 1729. ---- considered common to all metals, 66. ---- ---- conductors, 76. ---- is a state of tension, 71. ---- is dependent on particles, 73. Elementary bodies probably ions, 849. Elements evolved by force of the current, 493, 520, 524. ---- at the poles, why, 535. ---- determined to either pole, 552, 681, 757. ----, transference of, 454, 538. ----, if not combined, do not travel, 544, 546. Equivalents, electro-chemical, 824, 833, 855. ----, chemical and electro-chemical, the same, 836, 839. Ether, interference of, 651. Evolution of electricity, 1162, 1737. ---- of one electric force impossible, 1175. ---- of elements at the poles, why, 535. Excitation, electrical, 1737. ---- by chemical action, 878, 916, 1739. ---- by friction, 1744. Exclusive induction, 1681.

Flame favours convectivc discharge, 1580. Flowing water, electric currents in, 190. Fluid terminations for convection, 1581. Fluids, their adhesion to metals, 1038. Fluoride of lead, hot, conducts well, 1340. Force, chemical, local, 947, 959, 1739. ----, circulating, 917, 947, 996, 1120. Force, electric, nature of, 1163, 1667. ----, inductive, of currents, its nature, 60, 1113, 1735. Forces, electric, two, 1163. ----, inseparable, 1163, 1177, 1244, 1627. ---- and chemical, are the same, 877, 916. ---- and magnetic, relation of, 1411, 1653, 1658, 1709. ---- ----, are they essentially different? 1663, 1731. Forces, exciting, of voltaic apparatus, 887, 916. ----, exalted, 905, 994, 1138, 1148. Forces, polar, 1665. ---- of the current, direct, 1620. ---- ----, lateral or transverse, 1653, 1709. Form, its influence on induction, 1302, 1374. ---- discharge, 1372, 1374. Fox, his terrestrial electric currents, 187. Friction electricity, its characters, 284. ----, excitement by, 1744. Fusion, conduction consequent upon, 394, 402. Fusinieri, on combination effected by platina, 613.

Galvanometer, affected by common electricity, 289, 366. ----, a correct measure of electricity, 367, note. Gases, their elasticity, 626, 657. ----, conducting power, 1336. ----, insulating power, 1381, 1507. ----, ---- not alike, 1395, 1508. ----, specific inductive capacity, 1283, 1290. ----, ---- alike in all, 1292. ----, specific influence on brush and spark, 1463, 1687. ----, discharge, disruptive, through, 1381. ----, brush in, 1454. ----, spark in, 1421. ----, positive and negative brushes in, 1475. ----, ----, their differences, 1476. ----, positive and negative discharge in, 1393, 1506, 1687. ----, solubility of, in cases of electrolyzation, 717, 728. ----, from water, spontaneous recombination of, 566. ----, mixtures of, affected by platina plates, 571. ----, mixed, relation of their particles, 625. General principles of definite electrolytic action, 822. ---- remarks on voltaic batteries, 1031, 1136. ---- results as to conduction, 443. ---- ---- induction, 1295. Glass, its conducting power, 1239. ----, its specific inductive capacity, 1271. ----, its attraction for air, 622. ----, ---- water, 1251. Globe, revolving of Barlow, effects explained, 137, 160. ----, is magnetic, 164. Glow, 1405, 1525. ----, produced, 1527. ----, positive, 1527. ----, negative, 1530. ----, favoured by rarefaction of air, 1529. ----, is a continuous charge of air, 1526, 1537, 1543. ----, occurs in all gases, 1534. ----, accompanied by a wind, 1535. ----, its nature, 1543, ----, discharge, 1526. ----, brush and spark relation of, 1533, 1538, 1539, 1542. Grotthuss' theory of electro-chemical decomposition, 481, 499, 515. Growth of a brush, 1437. ---- spark, 1553.

Hachette's view of electro-chemical decomposition, 491. Hare's voltaic trough, 1123, 1132. Harris on induction in air, 1363. Heat affects the two electrodes, 1637. ---- increases the conducting power of some bodies, 432, 438, 1340. ----, its conduction related to that of electricity, 416. ----, as a result of the electric current, 853, note, 1625, 1630. ---- evolved by animal electricity, 353. ---- ---- common electricity, 287. ---- ---- magneto-electricity, 344. ---- ---- thermo-electricity, 349. ---- ---- voltaic electricity, 276. Helix, inductive effects in, 1061, 1094. Hydriodic acid, its electrolyses, 767, 787. Hydrocyanic acid, its electrolyses, 771, 788. Hydrofluoric acid, not electrolysable, 770. Hydrogen, brush in, 1459. ----, positive and negative brush in, 1476. ----, ---- discharge in, 1514. Hydrogen and oxygen combined by platina plates, 570, 605. ---- spongy platina, 609.

Ice, its conducting power, 419. ---- a non-conductor of voltaic currents, 381. Iceland crystal, induction across, 1695. Identity, of electricities, 265, 360. ---- of chemical and electrical forces, 877, 917, 947, 961, 1031. Ignition of wire by electric current, 853, note, 1630. Improved voltaic battery, 1006, 1120. Increase of cells in voltaic battery, effect of, 990.

Inducteous surfaces, 1483. Induction apparatus, 1187. ----, fixing the stem, 1190, 1193, 1200. ----, precautions, 1194, 1199, 1213, 1232, 1250. ----, removal of charge, 1203. ----, retention of charge, 1205, 1207. ----, a charge divided, 1208. ----, peculiar effects with, 1233. Induction, static, 1161. ----, an action of contiguous particles, 1165, 1231, 1253, 1295, 1450, 1668, 1679. ----, consists in a polarity of particles, 1298, 1670, 1679. ----, continues only in insulators, 1298, 1324, 1338. ----, intensity of, sustained, 1362. ----, influenced by the form of conductors, 1302. ----, ---- distance of conductors, 1303. ----, ---- relation of the bounding surfaces, 1483. ----, charge, a case of, 1171, 1177, 1300. ----, exclusive action, 1681. ----, towards space, 1614. ----, across a vacuum, 1614. ---- through air, 1217, 1284. ---- ---- different gases, 1381, 1395. ---- ---- crystals, 1689, ---- ---- lac, 1228, 1255, 1308. ---- ---- metals, 1329, 1332. ---- ---- all bodies, 1331, 1334. ----, its relation to other electrical actions, 1165, 1178. ----, ---- insulation, 1324, 13602, 1368, 1678. ----, ---- conduction, 1320. ----, ---- discharge, 1319, 1323, 1362. ----, ---- electrolyzation, 1164, 1343. ----, ---- intensity, 1178, 1362. ----, ---- excitation, 1178, 1740. ----, its relation to charge, 1177, 1299. ---- an essential general electric function, 1178, 1299. ----, general results as to, 1295. ----, theory of, 1165, 1231, 1295, 1667, 1669. ---- in curved lines, 1166, 1215, 1679. ---- ----, through air, 1218, 1449. ---- ----, ---- other gases, 1226. ---- ----, ---- lac, 1228. ---- ----, ---- sulphur, 1228. ---- ----, ---- oil of turpentine, 1227. induction, specific, 1167, 1252, 1307. ----, the problem stated, 1252. ----, ---- solved, 1307. ----, of air, 1284. ----, ----, invariable, 1287, 1288. ----, of gases, 1283, 1290. ----, ---- alike in all, 1292. ----, of shell-lac, 1256, 1269. ----, glass, 1271. ----, sulphur, 1275. ----, spermaceti, 1279. ----, certain fluid insulators, 1280. Induction of electric currents, 6, 34, 232, 241, 1048, 1089, 1101, 1660, 1718. ----, on aiming the principal current, 10, 238, 1101. ----, on stopping the principal current, 10, 17, 238, 1087, 1100. ---- by approximation, 18, 236. ---- by increasing distance, 19, 237. ---- effective through conductors, 1719, 1721, 1735. ---- ---- insulators, 1719, 1722, 1735. ---- in different metals, 193, 202, 211, 213. ---- in the moving earth, 181. ---- in flowing water, 190. ---- in revolving plates, 85, 240. ----, the induced current, its direction, 26, 232. ----, ---- duration, 19, 47, 89. ----, ----, traverses fluids, 20, 23. ----, ----, its intensity in different conductors, 183, 193, 201, 211, 213. ----, ----, not obtained by Leyden discharge, 24. ----, Ampere's results, 78, 255, 379, note. Induction of a current on itself, 1048, 1109. ----, apparatus used, 1052. ----, in a long wire, 1064, 1068, 1092, 1118. ----, ---- doubled wire, 1096. ----, ---- helix, 1053, 1061. ---- in doubled helices, 1096. ---- in an electro-magnet, 1056, 1060. ----, wire and helix compared, 1065. ----, short wire, effects with, 1067. ----, action momentary, 1070, 1091, 1100. ----, causes no permanent change in the current, 1071. ----, not due to momentum, 1077. ----, induced current separated, 1078, 1089. ----, effect at breaking contact, 1060, 1081, 1084, 1087. ----, ---- making contact, 1101, 1106. ----, effects produced, shock, 1060, 1064, 1079. ----, ---- spark, 1060, 1064, 1080. ----, ---- chemical decomposition, 1084. ----, ---- ignition of wire, 1081, 1104. ----, cause is in the conductor, 1059, 1070. ----, general principles of the action, 1093, 1107. ----, direction of the forces lateral, 1108. induction, magnetic, 255, 1658, 1710. ----, by intermediate particles, 1663, 1710, 1729, 1735. ----, through quiescent bodies, 1712, 1719, 1720, 1735. ----, ---- moving bodies, 1715, 1716, 1719. ---- and magneto-electric, distinguished, 138, 215, 243, 253. Induction, magneto-electric, 27, 58, 81, 140, 193, 1709. See Arago's magnetic phenomena. ----, magnelectric, 58. ----, electrolytic, 1164, 1345, 1702, 1740. ----, volta-electric, 26.

Inductive capacity, specific, 1167, 1252. Inductive force of currents lateral, 26, 1108. ----, its nature, 1113, 1660, 1663, 1709. Inductive force, lines of, 1231, 1297, 1304. ----, often curved, 1219, 1224, 1230. ----, exhibited by the brush, 1449. ----, their lateral relation, 1231, 1297, 1304. ----, their relation to magnetism, 1411, 1658, 1709. Inductometer, differential, 1307, 1317. Inductric surfaces, 1483. Inexhaustible nature of the electric 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, 951. ----, electric, 1405, 1445, 1560, note. ----, ----, spark, 1406, 1553. ----, ----, brush, 1425, 1444, 1445. ----, ----, glow, 1526. Lightning, 1420, 1404, 1641. Lines of inductive force, 1231, 1304, ---- often curved, 1219, 1224, 1230. ----, as shown by the brush, 1449. ----, their lateral relation, 1231, 1297, 1304. ----, their relation to magnetism, 1411, 1658, 1709. Liquefaction, conduction consequent upon, 380, 394, 410. Liquid bodies which are non-conductors, 405. Local chemical affinity, 947, 959, 961, 1739.

Machine, electric, evolution of electricity by, 1748. ------, magneto-electric, 135, 154, 158, 1118. Magnelectric induction, 58. ----, collectors or conductors, 86. Magnesia, sulphate, decomposed against water, 494, 533. ----, transference of, 495. Magnet, a measure of conducting power, 216. ---- and current, their relation remembered, 38, note. ---- ---- plate revolved together, 218. ---- ---- cylinder revolved together, 219. ---- revolved alone, 220, 223. ---- and moving conductors, their general relation, 256. ---- made by induced current, 13, 14. ----, electricity from, 36, 220, 223. Magnetic bodies, but few, 255. ----, curves, their inductive relation, 217, 232. ---- effects of voltaic electricity, 277. ---- ---- common electricity, 288, 367. ---- ---- magneto-electricity, 27, 83, 345. ---- ---- thermo-electricity, 349. ---- ---- animal electricity, 354. ---- and electric forces, their relation, 118, 1411, 1653, 1658, 1709, 1731. ---- forces active through intermediate particles, 1663, 1710, 1729, 1735. ---- forces of the current, 1653. ---- ---- very constant, 1654. ---- deflection by common electricity, 289, 296. ---- phenomena of Arago explained, 81. ---- induction. See Induction, magnetic. ---- induction through quiescent bodies, 1712, 1719, 1720, 1735. ---- ---- moving bodies, 1715, 1719. ---- and magneto-electric action distinguished, 138, 215, 243, 253. Magnetism, electricity evolved by, 27. ----, its relation to the lines of inductive force, 1411, 1658, 1709. ---- bodies classed in relation to, 255. Magneto-electric currents, their intensity, 183, 193, 211, 213. ----, their direction, 114, 110. ---- traverse fluids, 33. ---- momentary, 30. ---- permanent, 89. ---- in all conductors, 193, 213. Magneto-electric induction, 27, 58. ----, terrestrial, 110, 181. ----, law of, 114. ----. See Arago's magnetic phenomena. Magneto-electric machines, 135, 154, 158. ----, inductive effects in their wires, 1118, Magneto-electricity, its general characters considered, 343, &c. ---- identical with other electricities, 360. ----, its tension, 343. ----, evolution of heat, 344. ----, magnetic force, 345. ----, chemical force, 346. ----, spark, 348. ----, physiological effects, 347. ----. See Induction, magnetic. Matter, atoms of, 869, 1703. ----, new condition of, 60, 231, 242, 1114, 1661, 1729. ----, quantity of electricity in, 852, 861, 873, 1652. ----, absolute charge of, 1169. Measures of electricity, galvanometer, 367, note. ----, voltameter, 704, 736, 739. ----, metal precipitated, 740, 842. Measure of specific inductive capacity, 1307, 1600. Measurement of common and voltaic electricities, 361, 860, 1652. ---- electricity, degree, 736, 738. ---- ---- by voltameter, 704, 736, 739. ---- ---- by galvanometer, 367, note. ---- ---- by metal precipitated, 740, 842. Mechanical forces affect chemical affinity, 656. Mercurial terminations for convection, 1581. Mercury, periodide of, an exception to the law of conduction? 691, 1341. ----, perchloride of, 692, 1341. Metallic contact not necessary for electrolyzation, 879. ---- not essential to the voltaic current, 879, 887, 915. ---- its use in the pile, 893, 896. Metallic poles, 557.

Metal and electrolyte, their state, 946. Metals, adhesion of fluids to, 1038. ----, their power of inducing combination 564, 608. ----, ---- interfered with, 638. ----, static induction in, 1329, 1332. ----, different, currents induced in, 193, 211. ----, generally secondary results of electrolysis, 746. ---- transfer chemical force, 918. ----, transference of, 539, 545. ---- insulate in a certain degree, 1328. ----, convective currents in, 1603. ----, but few magnetic, 255. Model of relation of magnetism and electricity, 116. Molecular inductive action, 1164, 1669. Motion essential to magneto-electric induction, 39, 217, 256. ---- across magnetic curves, 217. ---- of conductor and magnet, relative, 114. ---- ---- not necessary, 218. Moving magnet is electric, 220. Muriatic acid gas, its high insulating power, 1395. ----, brush in, 1462. ----, dark discharge in, 1554. ----, glow in, 1534. ----, positive and negative brush in, 1476. ----, spark in, 1422, 1463. ----, ----, has no dark interval, 1463, 1555. Muriatic acid decomposed by common electricity, 314. ----, its electrolysis (primary), 758, 786.

Nascent state, its relation to combination, 658, 717. Natural standard of direction for current, 663. ---- relation of electrolytic intensity, 987. Nature of the electric current, 1617. ---- force or forces, 1667. Negative current, none, 1627, 1632. ---- discharge, 1465, 1484. ---- ----, as Spark, 1467, 1482. ---- ----, as brush, 1466, 1502. ---- spark or brush, 1484, 1502. Negative and positive discharge, 1465, 1482, 1525 ---- in different gases, 1393. New electrical condition of matter, 60, 231, 242, 1114, 1661, 1729. ---- law of conduction, 380, 394, 410. Nitric acid formed by spark in air, 324. ---- favours excitation of current, 906, 1138 ---- ---- transmission of current, 1020. ---- is best for excitation of battery, 1137. ----, nature of its electrolysis, 752. Nitrogen determined to either pole, 554, 748, 752. ---- a secondary result of electrolysis, 746, 748. ----, brush in, 1458. ----, dark discharge in, 1559. ----, glow in, 1534. ----, spark in, 1422, 1463. ----, positive and negative brush in, 1476. ----, ---- discharge in, 1512. ----, its influence on lightning, 1464. Nomenclature, 662, 1483. Nonconduction by solid electrolytes, 381, 1358, 1705. Note on electrical excitation, 1737. Nuclei, their action, 623, 657.

Olefiant gas, interference of, 610, 652. Ordinary electricity, its tension, 285. ---- evolution of heat, 287. ---- magnetic force, 288, 362. ---- chemical force, 309, 454. ---- ----, precautions, 322. ---- spark, 333. ---- physiological effect, 332. ---- general characters considered, 284. ----, identity with other electricities, 360. Origin of the force of the voltaic pile, 878, 910, 919. Oxidation the origin of the electric current in the voltaic pile, 919, 930. Oxide of lead electrolysed, 797. Oxygen, brush in, 1457. ----, positive and negative brush in, 1476, ----, ---- discharge in, 1513. ----, solubility of, in cases of electrolyzation, 717, 728. ----, spark in, 1422. ---- and hydrogen combined by platina plates, 570, 605, 630. ---- ---- spongy platina, 609, 636. ---- ---- other metals, 608.

Particles, their nascent state, 658. ---- in air, how charged, 1564. ----, neighbouring, their relation to each other, 619, 624, 657. ----, contiguous, active in induction, 1165, 1677. ---- of a dielectric, their inductive condition, 1369, 1410, 1669. ----, polarity of, when under induction, 1298, 1676. ----, how polarised, 1669, 1679. ----, ----, in any direction, 1689. ----, ----, as wholes or elements, 1699. ----, ----, in electrolytes, 1702. ----, crystalline, 1689. ----, contiguous, active in electrolysis, 1349, 1702. ----, their action in electrolyzation, 520, 1343, 1703. ----, ---- local chemical action, 961, 1739. ----, ---- relation to electric action, 73. ----, ---- electric action, 1669, 1679, 1740. Path of the electric spark, 1107. Phosphoric acid not an electrolyte, 682. Physiological effects of voltaic-electricity, 279. ---- common electricity, 332. ---- magneto-electricity, 56, 347. ---- thermo-electricity, 349. ---- animal electricity, 357. Pile, voltaic, electricity of, 875. ----. See Battery, voltaic. Plates of platina effect combination, 568, 571, 590, 630. ---- prepared by electricity, 570, 585, 588. ---- ---- friction, 591. ---- ---- heat, 595. ---- ---- chemical cleansing, 599, 605, ----, clean, their general properties, 633, 717. ----, their power preserved, 576. ----, ---- in water, 580. ----, their power diminished by action, 581. ----, ---- exposure to air, 636. ----, their power affected by washing in water, 582. ----, ---- heat, 584, 597. ----, ---- presence of certain gases, 638, 655. ----, their power, cause of, 590, 616, 630. ----, theory of their action, Doebereiner's, 610. ----, ----, Dulong and Thenard's, 611. ----, ----, Fusinieri's, 613. ----, ----, author's, 619, 626, 630, 656. Plates of voltaic battery foul, 1145. ----, new and old, 1116. ----, vicinity of, 1148. ----, immersion of, 1003, 1150. ----, number of, 989, 1151. ----, large or small, 1154. Platina, clean, its characters, 633, 717. ---- attracts matter from the air, 634. ----, spongy, its state, 637. ----, clean, its power of effecting combination, 564, 590, 605, 617, 630. ----, ---- interfered with, 638. ----, its action retarded by olefiant gas, 640, 652. ----, ----, carbonic oxide, 645, 652. ----. See Combination, Plates of platina, and Interference. ---- poles, recombination effected by, 567, 588. Plumbago poles for chlorides, 794. Poisson's theory of electric induction, 1305. Points, favour convective discharge, 1573. ----, fluid for convection, 1581. Polar forces, their character, 1665. ---- decomposition by common electricity, 312, 321, 469. Polarity, meaning intended, 1304, 1685. ---- of particles under induction, 1298, 1676. ----, electric, 1070, 1085. ----, ----, its direction, 1688, 1703, ----, ----, its variation, 1687. ----, ----, its degree, 1686. ----, ----, in crystals, 1689. ----, ----, in molecules or atoms, 1699. ----, ----, in electrolytes, 1702. Polarized light across electrolytes, 951. Poles, electric, their nature, 461, 498, 556, 662. ----, appearance of evolved bodies at, accounted for, 535. ---- one element to either? 552, 681, 757. ----, of air, 455, 461, 559. ----, of water, 491, 558. ----, of metal, 557. ----, of platina, recombination effected by, 567, 588. ----, of plumbago, 794.

Poles, magnetic, distinguished, 44, note. Porrett's peculiar effects, 1646. Positive current none, 1627, 1632. ---- discharge, 1465, 1480. ---- ----, as spark, 1467, 1482. ---- ----, as brush, 1467, 1476. ---- spark or brush, 1484, 1502. ---- and negative, convective discharge, 1600. ---- ---- disruptive discharge, 1465, 1482, 1485, 1525. ---- ---- ---- in different gases, 1393. ---- ---- voltaic discharge, 1524. ---- ---- electrolytic discharge, 1525. Potassa acetate, nature of its electrolysis, 749. Potassium, iodide of, electrolysed, 805. Power of voltaic batteries estimated, 1126. Powers, their state of tension in the pile, 949. Practical results with the voltaic battery, 1136. Pressure of air retains electricity, explained, 1377, 1398. Primary electrolytical results, 742. Principles, general, of definite electrolytic action, 822. Proportionals in electrolytes, single, 679, 697.

Quantity of electricity in matter, 852, 861, 873, 1652. ---- voltaic battery, 990.

Rarefaction of air facilitates discharge, why, 1375. Recombination, spontaneous, of gases from water, 566. Relation, by measure, of electricities, 361. ---- of magnets and moving conductors, 256. ---- of magnetic induction to intervening bodies, 1662, 1728. ---- of a current and magnet, to remember, 38, note. ---- of electric and magnetic forces, 118, 1411, 1653, 1658,1709, 1731. ---- of conductors and insulators, 1321, 1326, 1334, 1338. ---- of conduction and induction, 1320, 1337. ---- of induction and disruptive discharge, 1362. ---- ---- electrolyzation, 1164, 1343. ---- ---- excitation, 1178, 1740. ---- ---- charge, 1171, 1177, 1300. ---- of insulation and induction, 1324, 1362, 1368, 1678. ----, lateral, of lines of inductive force, 1231, 1297, 1304. ---- of a vacuum to electricity, 1613. ---- 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 to its repetition, 1392. ----, facilitates discharge, 1417, 1553. ----, passes into brush, 1448. ----, preceded by induction, 1362. ----, forms nitric acid in air, 324. ----, in gases, 1383, 1421. ----, in air, 1422. ----, in nitrogen, 1422, 1463. ----, in oxygen, 1422. ----, in hydrogen, 1422. ----, in carbonic acid, 1422, 1463. ----, in muriatic acid gas, 1422, 1463. ----, in coal-gas, 1422. ----, in liquids, 1424. ----, precautions, 958, 1074. ----, voltaic, without metallic contact, 915, 956. ---- from single voltaic pair, 1050. ---- from common and voltaic electricity assimilated, 334. ----, first magneto-electric, 32. ---- of voltaic electricity, 280. ---- of common electricity, 333. ---- of magneto-electricity, 348. ---- of thermo-electricity, 349. ---- of animal electricity, 358. ----, brush and glow related, 1533, 1539, 1542. Sparks, their expected coalition, 1412. Specific induction. See Induction, specific, 1252. Specific inductive capacity, 1252. ----, apparatus for, 1187. ---- of lac, 1256, 1270, 1308. ---- of sulphur, 1275, 1310. ---- of air, 1284. ---- of gases, 1283, 1290. ---- of glass, 1271. Spermaceti, its conducting power, 1240, 1323. ----, its relation to conduction and insulation, 1322. Standard of direction in the current, 663. State, electrotonic, 60, 231, 242, 1114, 1661, 1729.

Static induction. See Induction, static. Sturgeon, his form of Arago's experiment, 249. ----, use of amalgamated zinc by, 863, 999. Sulphate of soda, decomposed by common electricity, 317. ----, electrolytic intensity for, 975. Sulphur determined to either pole, 552, 681, 757. ----, its conducting power, 1241, 1245. ----, its specific inductive capacity, 1275. ----, copper and iron, circle, 943. Sulphuret of carbon, interference of, 650. ---- silver, hot, conducts well, 433. Sulphuretted solution excites the pile, 943. Sulphuric acid, conduction by, 409, 681. ----, magneto-electric induction on, 200, 213. ---- in voltaic pile, its use, 925. ---- not an electrolyte, 681. ----, its transference, 525. ----, its decomposition, 681, 757. Sulphurous acid, its decomposition, 755. Summary of conditions of conduction, 443. ---- molecular inductive theory, 1669.

Table of discharge in gases, 1388. ---- electric effects, 360. ---- electro-chemical equivalents, 847. ---- electrolytes affected by fusion, 402. ---- insulation in gases, 1388. ---- ions, anions, and cathions, 847. Tartaric acid, nature of its electrolysis, 775. Tension, inductive, how represented, 1370. ---- of voltaic electricity, 268. ---- of common electricity, 285. ---- of thermo-electricity, 349. ---- of magneto-electricity, 343. ---- of animal electricity, 352. ---- of zinc and electrolyte in the voltaic pile, 949. Terrestrial electric currents, 187. Terrestrial magneto-electric induction, 140. ---- cause of aurora borealis, 192. ----, electric currents produced by, 141, 150. ----, ----, in helices alone, 148. ----, ----, ---- with iron, 141, 146. ----, ----, ---- 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. ----, its relation to the combining oxygen, 921, 962. ----, ---- combining sulphur, 943. ----, ---- the transferred elements, 923, 962. ----, relation of bodies in, 962. Voltaic current, 1617. See Current, electric. Voltaic discharge, positive and negative, 1524. Voltaic decomposition, 450, 600. See Decomposition, electro-chemical. Voltaic electricity, identical with electricity, otherwise evolved, 268, 360. ----, discharged by points, 272. ----, ---- hot air, 271, 274. ----, its tension, 268, 275. ----, evolution of heat by, 276. ----, its magnetic force, 277. ----, its chemical force, 278. ----, its spark, 280. ----, its physiological effects, 279. ----, its general characters considered, 268. Voltaic pile distinguished, 856, note. ----, electricity of, 875. ----, depends on chemical action, 872. ----, relation of acid and bases in the, 927. ----. See Battery, voltaic. Voltaic spark without contact, 915, 956. ----, precautions, 958, 1074. Voltaic trough, 989. See Battery, voltaic.

Water, flowing, electric currents in, 190. ----, retardation of current by, 1159. ----, its direct conducting power, 1017, 1159, 1355. ----, ---- constant, 984. ----, electro-chemical decomposition against, 494, 532. ----, poles of, 494, 533, 558. ----, its influence in electro-chemical decomposition, 472. ---- is the great electrolyte, 924. ----, the exciting electrolyte when pure, 944. ----, ---- acidulated, 880, 926, 1137. ----, ---- alkalized, 931, 934, 941. ----, electrolytic intensity for, 968, 981, 1017. ---- electrolyzed in a single circuit, 862. ----, its electrolysis definite, 732, 785, 807. ----, decomposition of by fine wires, 327. ----, quantity of electricity in its elements, 853, 861. ----, determined to either pole, 553. Wheatstone's analysis of the electric brush, 1427. ---- measurement of conductive velocity in metals, 1328. Wire, ignition of, by the electric current, 853, note, 1631. ---- is uniform throughout, 1630. Wire a regulator of the electric current, 853, note. ----, velocity of conduction in, varied, 1333. ----, single, a current induced in, 170. ----, long, inductive effects in, 1064, 1118. Wollaston on decomposition by common electricity, 309. ---- decomposition of water by points, 327.

Zinc, amalgamated, its condition, 863, 1000. ----, used in pile, 999. Zinc, how amalgamated, 863. ----, of troughs, its purity, 1144. ----, its relation to the electrolyte, 949. ----, its oxidation is the source of power in the pile, 919. ---- plates of troughs, foul, 1145. ---- ----, new and old, 1146. ----, waste of, in voltaic batteries, 997.