EXPERIMENTAL RESEARCHES
IN ELECTRICITY

§ I, IDENTITY OF ELECTRICITIES DERIVED FROM DIFFERENT
SOURCES. § 2. RELATION BY MEASURE OF COMMON AND
VOLTAIC ELECTRICITY

§ i. Identity of Electricities derived from different sources

i. THE progress of the electrical researches which I have had
the honour to present to the Royal Society, brought me to a
point at which it was essential for the further prosecution of
my inquiries that no doubt should remain of the identity or
distinction of electricities excited by different means. It is per-
fectly true that Cavendish,2 Wollaston,3 Colladon 4 and others,
have in succession removed some of the greatest objections to
the acknowledgment of the identity of common, animal and
voltaic electricity, and I believe that most philosophers con-
sider these electricities as really the same. But on the other
hand it is also true, that the accuracy of Wollaston's experi-
ments has been denied;5 and also that one of them, which
really is no proper proof of chemical decomposition by common
electricity (45, 63), has been that selected by several experi-
menters as the test of chemical action (72, 82). It is a fact,
too, that many philosophers are still drawing distinctions
between the electricities from different sources; or at least
doubting whether their identity is proved. Sir Humphry
Davy, for instance, in his paper on the Torpedo,6 thought it

1 Third Series, original edition, vol. i. p. 76.

2 Phil. Trans. 1776, p. 196. 3 Ibid. 1801, p. 434.

4 Annales de Chimie, 1826, p. 62, etc. 5 Phil. Trans. 1832, p. 282, note.

6 Phil. Trans. 1829, p. 17. " Common electricity is excited upon non-
conductors, and is readily carried off by conductors and imperfect con-
ductors. Voltaic electricity is excited upon combinations of perfect and
imperfect conductors, and is only transmitted by perfect conductors or
imperfect conductors of the best kind. Magnetism, if it be a form of
electricity, belongs only to perfect conductors; and, in its modifications,
to a peculiar class of them." (Dr. Ritchie has shown this is not the case,
Phil. Trans. 1832, p. 294.) "Animal electricity resides only in the im-
perfect conductors forming the organs of living animals, etc."FAITHFUL KNIGHT OF GOD.d, J knelt one day