478 WEBER OX THE NATURE OF DIAMAGNETISM. 



portant to decide the question, whether the source of the dia- 

 magnetic force acting at a distance is to be found in the unvarying 

 ponderable constituents of bodies, or whether it arises from an 

 imponderable constituent, and is connected with a certain distri- 

 bution thereof. 



To decide this question the experiment made by M. Reich* 

 is of the highest importance, according to which both north and 

 south poles, when they act at the same time on the same side 

 of a piece of bismuth, by no means repel it with the sum of 

 the forces which they would individually exert, but only with 

 the difference of these forces. 



From this single experiment it might be concluded with the 

 greatest probability, that the origin of the diamagnetic force is 

 not to be sought for in the never-changing metallic particles 

 of the bismuth, but in an imponderable constituent moving be- 

 tween them, which, on the approach of the pole of a magnet, is 

 displaced and distributed differently according to the difference 

 of this pole. The origin of the diamagnetic force is thus placed 

 in the reciprocal action of two imponderable bodies, instead of 

 in the reciprocal action between ponderable and imponderable 

 bodies at a distance ; and the similar effect upon opposite poles 

 is then explained by the different distribution of the impon- 

 derable constituent in the bismuth which is produced by the 

 antithesis of the poles. The simultaneous approach of two oppo- 

 site poles on the same side must however have for I'esult, that 

 the imponderable constituent in the bismuth can neither assume 

 the one or the other distribution upon which depends the ap- 

 pearance of the diamagnetic force, whence the disappearance of 

 the diamagnetic foi'ce in this case is self-evident. 



But if it be now further asked, what is the nature of the im- 

 ponderable constituent which is distributed in such a different 

 manner in the bismuth on the approach of a north or south pole, 

 and then with this distribution constantly re-acts with a repul- 

 sive force upon the approached pole, there present themselves 

 only the two magnetic fluids, or the two electric fluids in the 

 form of molecular currents. At all events, before any other 

 assumption can appear admissible, the impossibility of explain- 

 ing the phEenomena in question by the known relations of the 

 above imponderables must be shown. 



From this it will be seen that Reich's experiment may be 

 * Pliilosophical Magazine for February 1849, p. 127. 



