WEBEK ON THE NATURE OF DIAMAGNETISM. 485 



First Experiment. 

 Position of the commutator A. 



Increasing numbers on inserting the iron bar in the annular 

 conductor. 



Decreasing numbers on withdrawing the iron bar from the 

 annular conductor. 



Second Experiment. 

 Position of the commutator B. 



Decreasing numbers on inserting the iron bar in the aniudar 

 conductor. 



' Increasing numbers on removing the iron bar from the annuhir 

 conductor. 



The position of the commutator A, and the case in which the 

 iron bar was removed from the annular conductoi', for which 

 consequentlj' a decrease in the deflection of the galvanometer was 

 observed, will serve to compare this experiment made with iron 

 with the former relative to bismuth. In the above experiments 

 with the bismuth, this case corresponds to the uneven series, for 

 which a higher state of tlie galvanometer resulted with the in- 

 duction continued in the same direction. It results conse- 

 quently that the bismuth induced a positive current under the 

 same conditions that iron induced a negative one, and vice versa. 



Hence the induction of electric currents by the diamagne- 

 tization of the bismuth is proved ; and it is at the same time 

 evident that the direction of these currents is constantly the 

 reverse of those induced by iron under the same circumstances, 

 precisely as it should be if bismuth contained magnetic fluids or 

 their equivalent, Ampere's currents, which are set in motion or 

 rotated under the influence of powerful magnets in exactly an 

 opposite du-ection to that in iron. The view advanced by Fara- 

 day a[)pears therefore to be placed beyond all doubt. 



Now although a rule has been found according to which the 

 variable diamagnetic conditions of bodies are determined for all 

 cases in such a manner that the collective eflTects appear as a 

 necessary consequence according to magnetic and electro-dyna- 

 mic laws, the cause of this rule remains still unknown and unex- 

 plained according to magnetic and electro-dynamic laws. For 

 if magnetic fluids are really contained in the diamagnetic bodies, 

 on the a|)proach of a magnet-pole, the one fluid must be at- 

 tracted, the other repelled ; and the direction of the separation 



