PARAMAGNETIC AND DIAMAGNETIC FORCES 343 



netic poles: the magnet moved promptly, and after some 

 oscillations 1 came to rest at the number 612; thus moving 

 from a smaller to a larger number. The other two ends 

 of the bars were next brought to bear upon the magnet: 

 a prompt deflection was the consequence, and the final 

 position of equilibrium was 526: the movement being from 

 a larger to a smaller number. We thus observe a mani- 

 fest polar action of the bismuth cylinders upon the mag- 

 net; one pair of ends deflecting it in one direction, and 

 the other pair deflecting it in the opposite direction. 



Substituting for the cylinders of bismuth thin cylinders 

 of iron, of magnetic slate, of sulphate of iron, carbonate 

 of iron, protochloride of iron, red ferrocyanide of potas- 

 sium, and other magnetic bodies, it was found that when 

 the position of the magnetic cylinders was the same as 

 that of the cylinders of bismuth, the deflection produced 

 by the former was always opposed in direction to that 

 produced by the latter; and hence the disposition of the 

 force in the diamagnetic body must have been precisely 

 antithetical to its disposition in the magnetic ones. 



But it will be urged, and indeed has been urged, against 

 this inference, that the deflection produced by the bismuth 

 cylinders may be due to induced currents excited in the 

 metal by its motion within the helices. In reply to this 

 objection, it may be stated, in the first place, that the de- 

 flection is permanent, and cannot therefore be due to in- 

 duced currents, which are only of momentary duration. 

 It has also been urged that such experiments ought to be 

 made with other metals, and with better conductors than 

 bismuth; for if due to currents of induction, the better 



1 To lessen these a coppor damper was made use of. 



