42.
---- 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,