WEBER ON THE NATURE OF DIAMAGNETISM. 479 



employed to establish more firmly a view already advanced by 

 Faraday (Experimental Researches, Art. 2429, 2430). Faraday 

 there states that "Theoretically, an explanation of the movements 

 of the diamagnetic bodies, and all the dynamic phaenomena conse- 

 quent upon the actions of magnets on them, might be offered in the 

 supposition that magnetic induction caused in them a contrary 

 state to that which it produced in magnetic matter ; i. e. that if 

 a particle of each kind of matter were placed in the magnetic 

 field both would become magnetic, and each would have its 

 axis parallel to the resultant of magnetic force passing through 

 it; but the particle of magnetic matter would have its north and 

 south poles opposite, or facing towards the contrary poles of the 

 inducing magnet, whereas with the diamagnetic particles the 

 reverse would be the case ; and hence would result approxima- 

 tion in the one substance, recession in the other. 



" Upon Ampere's theory, this view would be equivalent to the 

 supposition, that as currents are induced in iron and magnetics 

 parallel to those existing in the inducing magnet or battery wire; 

 so in bismuth, heavy glass and diamagnetic bodies, the cui'rents 

 induced are in the contrary direction. This would make the 

 currents in diamagnetics the same in direction as those which 

 are induced in diamagnetic conductors at the commencement of 

 the inducing current ; and those in magnetic bodies the same as 

 those produced at the cessation of the same inducing current. 

 No difficulty would occur as respects non-conducting magnetic 

 and diamagnetic substances, because the hypothetical currents 

 are supposed to exist not in the mass, but round the particles 

 of the matter.'^ 



I shall now submit this ingenious view, first proposed by 

 Faraday, and which has obtained greater probability from Reich's 

 experiment, to a still more direct criticism by the following ex- 

 periments, which, in my opinion, scarcely leave a doubt of its 

 correctness. 



All the diamagnetic forces hitherto observed have exhibited a 

 repulsive, never an attractive action; but from Faraday's assump- 

 tion, it follows that diamagnetic forces must likewise occur which 

 act attractively upon the pole of a magnet, and such cases may 

 easily be determined more accurately and tested by experiment. 



But for this purpose we must not observe the force which 

 the diamagnetic bismuth exerts upon that pole by which it has 

 been rendered diamagnetic, but those forces which this bismuth 



