140 MR. FARADAY’S EXPERIMENTAL RESEARCHES IN ELECTRICITY. 
pended on torsion balances in vacuo, near to the poles of very powerful mag¬ 
nets, yet have not been able to observe the least attractive or repulsive force. 
63. I have also arranged a fine slip of gold-leaf very near to a bar of copper, 
the two being in metallic contact by mercury at their extremities. These have 
been placed in vacuo, so that metal rods connected with the extremities of the 
arrangement should pass through the sides of the vessel into the air. I have 
then moved powerful magnetic poles, by 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, at¬ 
tractive 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. Ampere’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 ex¬ 
cited, 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 per¬ 
manent effects observed have been due to traces of iron, or some other unre¬ 
cognised 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 galvano¬ 
meter (20.), not the slightest permanent change in the indication of the instru¬ 
ment could be perceived. Metal in the supposed peculiar state, therefore, 
conducts electricity in all directions with its ordinary facility, or, in other 
words, its conducting power is not sensibly altered by it. 
