ed that I think all
excitement by friction is of this kind; on the contrary, certain
experiments lead me to believe, that in many cases, and perhaps in all,
effects of a thermo-electric nature conduce to the ultimate effect; and
there are very probably other causes of electric disturbance influential at
the same time, which we have not as yet distinguished.

_Royal Institution.
June, 1838._

INDEX.

* * * * *

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.

* * * * *

_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