similarly suspended exhibited the same deportment. For a moment I
thought this a new discovery; but on looking over the literature of
the subject, it appeared that Faraday had observed, multiplied, and
explained the same effect during his researches on diamagnetism.
His explanation was based upon his own great discovery of
magneto-electric currents. The effect is a most singular one.
A weight of several pounds of copper may be set spinning between the
electro-magnetic poles; the excitement of the magnet instantly stops
the rotation. Though nothing is apparent to the eye, the copper,
if moved in the excited magnetic field, appears to move through a
viscous fluid; while, when a flat piece of the metal is caused to
pass to and fro like a saw between the poles, the sawing of the
magnetic field resembles the cutting through of cheese or butter.[1]
This virtual friction of the magnetic field is so strong, that copper,
by its rapid rotation between the poles, might probably be fused.
We may easily dismiss this experiment by saying that the heat is due
to the electric currents excited in the copper. But so long as we
are unable to reply to the question, 'What is an electric current?'
the explanation is only provisional. For my own part, I look with
profound interest and hope on the strange action here referred to.

Faraday's thoughts ran intuitively into experimental combinations,
so that subjects whose capacity for experimental treatment would, to
ordinary minds, seem to be exhausted in a moment, were shown by him
to be all but inexhaustible. He has now an object in view, the
first step towards which is the proof that the principle of
Archimedes is true of magnetism. He forms magnetic solutions of
various degrees of strength, places them between the poles of his
magnet, and suspends in the solutions various magnetic bodies.
He proves that when the solution is stronger than the body plunged in