m 
tending to make the disc revolve. But, on the contrary, 
if the circuit were broken after the disc had assumed an 
equatorial position, the whole disc was swung towards the 
polar piece to which it happened to be the nearest, and 
with sufficient force to move the whole disc as a pendulum 
through an arc of two or three degrees; so that although 
the magnetic and dia-magnetic forces seemed as if balanced 
or neutralised, yet the revulsive forces corresponding with 
these were strongly manifested in either direction, as the 
case might be. It appeared always necessary that some 
time (about one second) should elapse before the magnet 
induced the dia-magnetic state ; but I did not, in any 
instance, observe the disc to be in a neutral state as 
regarded the revulsion. 
The motion communicated to the disc by the attractive 
revulsion is, however, very different from that exhibited by 
the repulsive revulsion. The latter always tended to make 
the disc revolve on its centre of suspension, both the edges 
being repelled from the polar pieces to which they were 
nearest ; but the attractive revulsion caused the entire disc 
to move towards the polar piece to which it was nearest, 
without exhibiting any tendency to make the disc revolve. 
For the purpose of ascertaining in what order different 
metals were affected magnetically and dia-magnetically, I 
instituted the following experiments; in which I made use of 
the eleven pound magnet, excited by the four cells of Grove’s 
battery, as before-mentioned. Platinum and palladium were 
procured from sources which I could not trace, and, as 
had been observed by Dr, Faraday, these metals took the 
axial position, with weak or strong powers, or with the 
polar pieces distant or close ; and the revulsion, although 
by no means so strongly developed as with other metals, 
was repulsive on breaking contact. Antimony and bismuth 
were from common commercial specimens, and had been 
