it, the body, though magnetic, is repelled; and when an elongated
piece of it is surrounded by the solution, it sets, like a
diamagnetic body, equatorially between the excited poles. The same
body when suspended in a solution of weaker magnetic power than
itself, is attracted as a whole, while an elongated portion of it
sets axially.

And now theoretic questions rush in upon him. Is this new force a
true repulsion, or is it merely a differential attraction? Might not
the apparent repulsion of diamagnetic bodies be really due to the
greater attraction of the medium by which they are surrounded?
He tries the rarefaction of air, but finds the effect insensible.
He is averse to ascribing a capacity of attraction to space, or to
any hypothetical medium supposed to fill space. He therefore
inclines, but still with caution, to the opinion that the action of
a magnet upon bismuth is a true and absolute repulsion, and not
merely the result of differential attraction. And then he clearly
states a theoretic view sufficient to account for the phenomena.
'Theoretically,' he says, 'an explanation of the movements of the
diamagnetic bodies, and all the dynamic phenomena consequent upon
the action of magnets upon them, might be offered in the supposition
that magnetic induction caused in them a contrary state to that
which it produced in ordinary matter.' That is to say, while in
ordinary magnetic influence the exciting pole excites adjacent to
itself the contrary magnetism, in diamagnetic bodies the adjacent
magnetism is the same as that of the exciting pole. This theory of
reversed polarity, however, does not appear to have ever laid deep
hold of Faraday's mind; and his own experiments failed to give any
evidence of its truth. He therefore subsequently abandoned it, and
maintained the non-polarity of the diamagnetic force.