7, 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.
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