296 MORRIS LOEB 



the non-magnetized [146] metal in this respect, or that the 

 north and south poles show dissimilar behavior. The experi- 

 ments were naturally crude, and a positive result, were it ad- 

 mitted, would obviously have been due to a polarized ar- 

 rangement of the molecules, rather than to variations in 

 chemical affinity. 



Next came the crystallization of salts or metals from a so- 

 lution, within and without a magnetic field. Quite a number 

 of observers appear to have found that the direction of growth, 

 either of the crystals themselves or of the clusters which they 

 form, can be affected by the presence of a magnetic field, 

 even though the substance be a diamagnetic. But what is 

 there in this that involves a modification of chemical action? 

 The quantity of deposit has not been observed to be altered 

 by the magnet; the physical arrangement of the molecules 

 during crystallization is always governed by directive forces 

 having no connection with affinity, and to the ordinary ones 

 is now superimposed the polarizing influence of the magnet. 



A different principle is involved in Remsen's experiments, 

 for they depend upon the removal of particles from a mag- 

 netized mass of iron, and the substitution therefor of faintly- 

 magnetic copper. The explanation of Messrs. Rowland and 

 Bell must appear highly plausible, that the resistance to such 

 removal must protect the more highly magnetized points 

 from reaction, so long as there are places where the iron can 

 be more readily dissolved. We have here a purely mechanical 

 reason for the localization of the reaction, in a non-uniform 

 field. That the total amount of reaction would not be affected 

 we may infer from a recent experiment by Fossati, 1 in which he 

 shows that the weight of iron precipitated from a solution by 

 zinc is not affected by the presence of a strong magnetic field. 



1 Bolletino delV Elettrirista, 1890. I quote from Wiedemann's Beibtttter, 1890, p. 

 1010, which alone is at my disposal. 



