136 
lead it is strongly exhibited; and in copper, which is con- 
sidered to be the best known conductor, we have the 
revulsion very strongly exhibited. We cannot account for 
the revulsive motions on the generally received hypothesis 
of induced secondary currents, for, as I have before pointed 
out with regard to magnetism and dia-magnetism, such 
currents would only account for revulsion in one direction. 
I conceive that the revulsive motions are caused by the 
magnetic affection of the piece of metal induced by electric 
currents, which currents are produced in the metal on the 
subsidence of the molecular disturbance, previously caused 
therein. It would be difficult to say how, on the determi- 
nation of the attractive polar condition of a piece of metal 
affected magnetically, a current should be produced which 
should reverse the polarity, and develope a greater force 
in the opposite direction ; but it is not the strictly magnetic 
polarity which precedes the repulsive revulsion, but that 
molecular condition which takes place in the intermediate 
or sluggish state, that, as I conceive, is the immediate 
cause of the induction of the current. Thus with platina 
and palladium we have little, if any, revulsion exhibited, 
these being affected only magnetically, and not passing 
into the intermediate state ; whilst with all the metals which 
are magnetic under one amount of force, and become dia- 
magnetic under an increase of force, and all of which 
pass through the intermediate or sluggish state, we have 
the revulsive motion strongly developed. It must also be 
observed that in the metals, antimony and bismuth, which 
are not affected as magnetic previously to becoming dia- 
magnetic, the phenomena of revulsion are not exhibited. 
I therefore submit that the metals which have been 
observed to change from the magnetic to the dia-magnetic 
states, are subject to three different conditions of molecular 
arrangement ; first, one of magnetic polarity, and which 
