extremities of the arrangement should pass through the sides of the vessel
into the air. I have then moved powerful magnetic poles, about this
arrangement, in various directions, the metallic circuit on the outside
being sometimes completed by wires, and sometimes broken. But I never could
obtain any sensible motion of the gold-leaf, either directed to the magnet
or towards the collateral bar of copper, which must have been, as far as
induction was concerned, in a similar state to itself.

64. In some cases it has been supposed that, under such circumstances,
attractive and repulsive forces have been exhibited, i.e. that such bodies
have become slightly magnetic. But the phenomena now described, in
conjunction with the confidence we may reasonably repose in M. Ampère's
theory of magnetism, tend to throw doubt on such cases; for if magnetism
depend upon the attraction of electrical currents, and if the powerful
currents at first excited, both by volta-electric and magneto-electric
induction, instantly and naturally cease (12. 28. 47.), causing at the same
time an entire cessation of magnetic effects at the galvanometer needle,
then there can be little or no expectation that any substances not
partaking of the peculiar relation in which iron, nickel, and one or two
other bodies, stand, should exhibit magneto-attractive powers. It seems far
more probable, that the extremely feeble permanent effects observed have
been due to traces of iron, or perhaps some other unrecognised cause not
magnetic.

65. This peculiar condition exerts no retarding or accelerating power upon
electrical currents passing through metal thus circumstanced (20. 33.).
Neither could any such power upon the inducing current itself be detected;
for when masses of metal, wires, helices, &c. were arranged in all possible
ways by the side of a wire or helix, carrying a current measured by the
galvanometer (20.), not the slightest permanent change in the indication of