^ve to an electrometer the same amount of electricity as they
ilo if, whilst simUarly cJectriflcd, th.ej are kept forcibly to-
gether. This experiment is the conyerso of the former one.
There is an advantage in electrical experiments of this clasa
as compared with those on heat, via. that though there ia no
perfect insulation for electricity, yet our means of insula-
tion are immeasurably superior to any attainable for heat.
Electricity directly produces heat, as shown ia the ignited
wire, the electric spark, and the voltaic arc : in the Iatt«r
the most intense heat with which we are acquainted — so in-
tense, indeed, that it cannot he measured, as every sort of
matter is dissipated by it.
