, 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, 8