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Article IX. 



On the Relation of Magnetism to Diamagnetism*. By M. 

 Pllcker, Professor of Natural Philosophy in the Univer- 

 sity of Bonn. 



[From Pogj;endorfF's Annalen, October 1847.] 



1. r ARADAY has completely disproved the view laid down by 

 other philosophers, viz. that diamagnetism is merely another 

 manifestation of ordinary magnetism, by the single fact, that 

 whilst a magnetic body (as instanced in iron) is attracted through- 

 out its mass by each of the two poles of a magnet, a diamagnetic 

 body is repelled by each pole throughout its entire mass. 



2. Hence the simplest supposition would be that, in which 

 the magnetic and diamagnetic forces called into action opposite 

 conditions of matter neutralizing each other ; a supposition which 

 at a glance is seen to be supported by the phsenomenon con- 

 stantly observed by Faraday, viz. that on mixing a magnetic and 

 a diamagnetic substance, an intermediate condition is produced, 

 •which depends upon the proportions of the mixture : we need 

 then only consider that the magnetic forces in ordinaiy cases 

 are incomparably stronger than the diamagnetic. Every dia- 

 magnetic body, when gradually mixed with a comparatively 

 small quantity of a substance containing iron, appears at first 

 less and less diamagnetic, and soon becomes magnetic. On the 

 other hand, it is only in the case of very feebly magnetic sub- 

 stances that we can succeed in converting the magnetic behaviour 

 of a more considerable mass into the diamagnetic by the ad- 

 mixture of a diamagnetic substance in not excessive quan- 

 tity. We must here however suppose that by such an admix- 

 ture the action of the magnetism is diminished, and that in a 

 greater degree than if the substance added acted like an indif- 

 ferent inactive mass. 



S. But what is even more opposed than anything to the sup- 

 position in the last paragraph, is the fact, that whilst an iron rod, 

 magnetically excited between the poles of a magnet, exhibits 

 polarity at its extremities, hitherto, notwithstanding all attempts, 

 no trace of polarity has been detected in a substance diamag- 



* Translated by Dr. J. W. Griffith. 



