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called normal, and the other class abnormal. A normal paramagnetic 

 bar is one which sets its length from pole to pole, in the magnetic 

 field, and a normal diamagnetic bar is one which sets its length at 

 right angles to the line joining the poles. An abnormal magnetic bar, 

 on the contrary, is one which sets its length equatorially ; while an 

 abnormal diamagnetic bar is one which sets its length axially. 



In all cases, whether operated on by the magnet alone, the cur- 

 rent alone, or the magnet and current combined, the deportment of 

 the normal paramagnetic bar is precisely antithetical to that of the 

 normal diamagnetic one. In the magnetic field the former sets 

 axially, the latter equatorially. Operated on by a voltaic current, the 

 former sets its length at right angles to the current, the latter sets 

 its length parallel to it. When magnet and current act together on 

 the bars, it is found that the disposition of forces which produces a 

 deflection from right to left of the paramagnetic bar produces a de- 

 flection from left to right of the diamagnetic bar. If the position 

 of equilibrium of the former be from N.E. to S.W., the position of 

 equilibrium of the latter is from N.W. to S.E. In short, the posi- 

 tion of rest for the normal magnetic bar is always at right angles to 

 the position of the diamagnetic bar. A precisely similar antithesis is 

 observed when we compare the abnormal paramagnetic bar with the 

 abnormal diamagnetic one. The former, in the magnetic field, sets 

 equatorially, the latter axially. The former sets parallel to an elec- 

 tric current, the latter perpendicular to the same. If the deflection 

 of the former be from right to left, the deflection of the latter, under 

 like conditions, is from left to right. Finally, the position of equi- 

 librium of the former is always at right angles to that of the latter. 



But if the deportment of the normal paramagnetic bar be com- 

 pared with that of the abnormal diamagnetic one, it will be found 

 that they are in all cases identical ; and the same identity of deport- 

 ment is exhibited when the abnormal paramagnetic bar is compared 

 with the normal diamagnetic one. The necessity of paying atten- 

 tion to structure in experiments of this nature could not, it is ima- 

 gined, be more strikingly exhibited. 



It is proved by these experiments that the simple substitution of 

 an attractive force for a repulsive one would completely convert the 

 phenomena exhibited by paramagnetic bodies into those exhibited 

 by diamagnetic ones. That if that which Gauss has called the ideal 



