117 
only one cell of the battery was employed, the current 
through the magnet being equal to about 30 grains of zinc 
per hour, or when the polar pieces were at a distance of 
not less than one inch, the last mentioned metals took the 
axial position, pointing in the same direction in which a 
piece of platina would have done. But when the battery 
power was increased, and the poles brought nearer together, 
instead of the disc of metal being more strongly attracted, 
it became less sensible to either attraction or repulsion, 
and was very sluggish in its motions, retaining for some 
time any position in which it was placed; and although it 
did not remain stationary, as mentioned by Dr. Faraday 
with regard to copper, yet it moved to the axial position 
very gradually, and without the oscillation it exhibited when 
the magnet w^as either more or less powerfully excited. 
But when the magnet was both well excited and the polar 
pieces brought within a quarter of an inch of each other, 
most of the before-mentioned metals took a decidedly equa- 
torial position, and were repelled as dia-magnetics, the 
sluggishness nearly disappeared, and the disc vibrated about 
the equatorial position as antimony or bismuth would have 
done. I shall afterwards more particularly mention the 
order in which such changes appeared to take place with 
various metals. 
As I experienced much difficulty in procuring specimens 
of metals perfectly free from any admixture of iron, I at 
first doubted whether the attraction of the metal did not 
depend on the presence of a minute portion of iron, and 
that the repulsion afterwards exhibited was due to the 
peculiar condition of the metal ; and I found that in some 
specimens of the metals which readily exhibited the pre- 
sence of a small quantity of iron by the ordinary chemical 
tests, the magnetic state was much more decided than with 
purer specimens. But as some of the metals were as free 
