462 Prof. W. Beetz on the Molecular Changes 



in the coil, and the deviation caused by it alone was determined ; 

 and lastly, the magnetizing current was again passed through the 

 coils, first in one direction, then in the other, and the deviations 

 due to the temporary and permanent magnetism of the bar were 

 read off. The numbers given below are only comparable for the 

 same magnet, since the distance of each of the magnets was 

 always so chosen that the reading off of the scale might be as 

 practicable as possible. 



Although in the above disposition of the experiment the pre- 

 cipitated particles had the opportunity of arranging themselves 

 in regular order, I nevertheless found, contrary to my first ex- 

 pectation, a considerable difference between the temporary and 

 permanent magnetism. In fact, however, assuming the hypo- 

 thesis of rotatory atoms equal in magnitude and magnetic power, 

 such atoms could only retain their parallel position, on the 

 cessation of the magnetizing current, on one condition, namely, 

 that all were at equal distances from each other. If this be not 

 the case, on the cessation of the current each molecular magnet 

 will place itself in the direction of the resultant of all the forces 

 acting on it, as is speedily the case when the precipitated plate 

 in the above experiment is removed from between the poles of 

 the magnet. Moreover, even between the poles of the strongest 

 magnets the precipitated molecules will not all arrange them- 

 selves in the same direction; for when once the cathode is 

 covered with a thin film of precipitated iron, the atoms that 

 follow are subjected to a double influence, viz. to that exerted at 

 a finite distance by the poles of the magnet, and secondly, to 

 that exerted at an insensible distance by the atoms already de- 

 posited. Now the latter force is directly opposed to the former, 

 as any one may easily convince himself experimentally, if, instead 

 of employing a horseshoe magnet as above described, the iron is 

 precipitated on a magnetic steel plate. The precipitate will then 

 be found to have a polarity contrary to that of the steel plate. 

 If, therefore, the precipitate between the poles of a magnet be 

 suffered to increase, each atomic layer partly cancels the polarity 

 of the other, and it is therefore impossible to obtain a thick 

 magnet as completely saturated as a thin one. A fully charged 

 magnet would be produced, if a row of polarized particles could 

 be obtained in a straight line. In order to accomplish this as 

 nearly as possible, I stretched a thin silver wire tightly over a 

 glass plate, and covered it with a thin layer of varnish, which, 

 when it had become dry, I scratched away from the side turned 

 away from the plate, so as to expose a strip of the surface of the 

 wire as narrow as possible. The plate was then placed in the 

 electrolytic apparatus between the poles of a magnet ; and in a 

 few minutes the wire was covered with a precipitate of iron. It 



