ubstances experimented on
between the poles of powerful horse-shoe magnets, he found that they were
all either attracted like iron, coming to rest with their greatest
length extending between the poles; or, like bismuth, were apparently
repelled by the poles, coming to rest at right angles to the position
assumed by iron. He regarded the first class of substances as attracted,
and the second class as repelled, and called them respectively
paramagnetic and diamagnetic substances. In other words, paramagnetic
substances, like iron, came to rest axially (extending from pole to
pole), and diamagnetic substances, like bismuth, equatorially (extending
transversely between the poles). He reserved the term magnetic
substances to cover the phenomena of both para and dia-magnetism. He
communicated the results of this investigation to the Royal Society in a
paper on the "Magnetic Condition of All Matter," on Dec. 18, 1845.

The properties of paramagnetism and diamagnetism are not possessed by
solids only, but exist also in liquids and gases. When experimenting
with liquids, they were placed in suitable glass vessels, such as watch
crystals, supported on pole pieces properly shaped to receive them.
Under these circumstances paramagnetic liquids, such as salts of iron or
cobalt dissolved in water, underwent curious contortions in shape, the
tendency being to arrange the greater part of their mass in the
direction in which the flux passed; namely, directly between the poles.
Diamagnetic liquids, such as solutions of salts of bismuth and antimony,
in a similar manner, arranged the greater part of their mass in
positions at right angles to this direction, or equatorially.

At first Faraday attributed the repulsion of diamagnetic substances to a
polarity, separate and distinct from ordinary magnetic polarity, for
which he proposed the name, diamagnetic polarity. He believed that when
a diamagnetic substance is brought near to the north pole of a magnet, a
north pole was developed in its approached end, and that therefore
repulsion occurred. He afterwards rejected this view, though it has
been subsequently adopted by Weber and Tyndall, the latter of whom
conducted an extended series of experiments on the subject. The majority
of physicists, however, at the present time, do not believe in the
existence of a diamagnetic polarity. They point out that the apparent
repulsion of diamagnetic substances is due to the fact that they are
less par