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became dia-magnetic. If the circuit were broken before 
the disc of zinc had decidedly assumed the equatorial 
position, the revulsion was strongly repulsive ; but the 
circuit being broken after the disc had assumed the equa- 
torial position, or nearly so, the disc was strongly attracted : 
and if the disc were rather nearer to one polar piece than 
the other, instead of the disc tending to revolve on its 
centre of suspension, as in the revulsion from the magnetic 
state, it was moved entirely toward the nearer polar piece, 
the whole mass being decidedly attracted. 
Gold , — The specimen used was a quarter-guinea piece; 
this was decidedly less inclined to become magnetic than 
zinc, when the polar pieces were at 0.75. 
The piece was magnetic at the first contact, afterwards 
very sluggish, and only slightly sensible to either attraction 
or repulsion. At 0.38, gold exhibited the like phenomena 
as zinc at 0.75, and also at shorter distances. 
The like phenomena were exhibited by zinc, as the polar 
pieces were progressively brought nearer each other, as 
afterwards mentioned. The change from the magnetic to 
the dia-magnetic state, and also in the direction of the 
revulsive motion on breaking circuit, was most decidedly 
shown when the polar pieces were at a distance of 0.37. 
I procured Lead by voltaic deposition from nitrate of 
lead, the metal thus obtained was redissolved in pure nitric 
acid, and again electrolitically deposited, then fused on 
glass, with the addition of a little tallow as a flux; the 
piece thus obtained appeared decidedly magnetic at 0.75 ; 
was very sluggish at 0.56 : took a diagonal position, with 
the edges of the disc nearly touching the polar pieces, 
but still sensibly separated. With closer adjustments of 
the polar pieces, lead behaved as the zinc had done at 
greater distances. 
Cadmium — (the purity of this was not tested, but it was 
