on the other of these doctrines; the invention of the torsion
balance; the determination that the attractive and repulsive forces
follow the law of the inverse squares; the conditions of distribution on
conductors; the elucidation of the phenomena of induction. [Sidenote:
Voltaic electricity.] At length, when discovery seemed to be pausing,
the facts of galvanism were announced in Italy. Up to this time it was
thought that the most certain sign of the death of an animal was its
inability to exhibit muscular contraction: but now it was shown that
muscular movements could be excited in those that are dead and even
mutilated. Then followed quickly the invention of the Voltaic pile.
[Sidenote: Results of the discovery of Galvani.] Who could have foreseen
that the twitching of a frog's leg in the Italian experiments would
establish beyond all question the compound nature of water, separating
its constituents from one another? would lead to the deflagration and
dissipation in a vapour of metals that could hardly be melted in a
furnace? would show that the solid earth we tread upon is an oxide?
yield new metals light enough to swim upon water, and even seem to set
it on fire? produce the most brilliant of all artificial lights,
rivalling if not excelling, in its intolerable splendour the noontide
sun? would occasion a complete revolution in chemistry, compelling that
science to accept new ideas, and even a new nomenclature? that it would
give us the power of making magnets capable of lifting more than a ton,
and cast a light on that riddle of ages, the pointing of the mariner's
compass north and south, explain the mutual attraction or repulsion of
magnetic needles? that it would enable us to form exquisitely in metal
casts of all kinds of objects of art, and give workmen a means of
gilding and silvering without risk to their health? that it would
suggest to the evil disposed the forging of bank notes, the
sophisticating of jewelry, and be invaluable in the uttering of false
coinage? that it would carry the messages of commerce and friendship
instantaneously across continents or under oceans, and "waft a sigh from
Indus to the pole?"

Yet this is only a part of what the Italian experiment, carried out by
modern methods, has actually done. Could there be a more brilliant
exhibition of their power, a brighter earnest of the future of material
philosophy?

[Sidenote: Discoveries in magnetism.] As it had been with amber, so with