fluoric 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.
----, disr