ertained by all scientific men, that the magnet
which you see and feel is an assemblage of molecular magnets which you
cannot see and feel, but which, as before stated, must be
intellectually discerned.

Magnetism then is a polar force; and experience hints that a force of
this kind may exert a certain structural power. It is known, for
example, that iron filings strewn round a magnet arrange themselves in
definite lines, called, by some, 'magnetic curves,' and, by others,
'lines of magnetic force.' Over two magnets now before me is spread a
sheet of paper. Scattering iron filings over the paper, polar force
comes into play, and every particle of the iron responds to that
force. We have a kind of architectural effort--if I may use the
term--exerted on the part of the iron filings. Here then is a fact of
experience which, as you will see immediately, furnishes further
material for the mind to operate upon, rendering it possible to attain
intellectual clearness and repose, while speculating upon apparently
remote phenomena.

The magnetic force has here acted upon particles visible to the eye.
But, as already stated, there are numerous processes in nature which
entirely elude the eye of the body, and must be figured by the eye of
the mind. The processes of chemistry are examples of these. Long
thinking and experimenting has led philosophers to conclude that
matter is composed of atoms from which, whether separate or in
combination, the whole material world is built up. The air we
breathe, for example, as mainly a mechanical mixture of the atoms of
oxygen and nitrogen. The water we drink is also composed of oxygen
and hydrogen. But it differs from the air in this particular, that in
water the oxygen and hydrogen are not mechanically mixed, but
chemically combined. The atoms of oxygen and those of hydrogen exert
enormous attractions on each other, so that when brought into
sufficient proximity they rush together with an almost incredible
force to form a chemical compound. But powerful as is the force with
which these atoms lock themselves together, we have the means of
tearing them asunder, and the agent by which we accomplish this may
here receive a few moments' attention.

Into a vessel containing acidulated water I dip two strips of metal,
the one being zinc and the other platinum, not permitting them to
touch each other in the liquid. I connect the two upper ends of the
strips by a piece of copper wire.