er
were three inches long, nearly an inch wide, and not a quarter of an inch
apart.

1160. These points, i.e. the increase of conducting power, the enlargement
of the electrodes, and their approximation, should be especially attended
to in _volta-electrometers_. The principles upon which their utility depend
are so evident that there can be no occasion for further development of
them here.

_Royal Institution,
October 11, 1834._

ELEVENTH SERIES.

S 18. _On Induction._ P i. _Induction an action of contiguous particles._
P ii. _Absolute charge of matter._ P iii. _Electrometer and inductive
apparatus employed._ P iv. _Induction in curved lines._ P v. _Specific
inductive capacity._ P vi. _General results as to induction._

Received November 30,--Read December 21, 1837.

P i. _Induction an action of contiguous particles._

1161. The science of electricity is in that state in which every part of it
requires experimental investigation; not merely for the discovery of new
effects, but what is just now of far more importance, the development of
the means by which the old effects are produced, and the consequent more
accurate determination of the first principles of action of the most
extraordinary and universal power in nature:--and to those philosophers who
pursue the inquiry zealously yet cautiously, combining experiment with
analogy, suspicious of their preconceived notions, paying more respect to a
fact than a theory, not too hasty to generalize, and above all things,
willing at every step to cross-examine their own opinions, both by
reasoning and experiment, no branch of knowledge can afford so fine and
ready a field for discovery as this. Such is most abundantly shown to be
the case by the progress which electricity has made in the last thirty
years: Chemistry and Magnetism have successively acknowledged its
over-ruling influence; and it is probable that every effect depending upon
the powers of inorganic matter, and perhaps most of those related to
vegetable and animal life, will ultimately be found subordinate to it.

1162. Amongst the actions of different kinds into which electricity has
conventionally been subdivided, there is, I think, none which excels, or
even equals in importance, that called _Induction_. It is of the most
general influence in electrical phenomena, appearing to be concerned in
every one of them, and has in reality the character of a first, essential,
and fundamental principle.