382 PLUCKER ON THE RELATION OF MAGNETISM, ETC. 



brane which Unes the shell internally. A piece of this membrane 

 was also magnetic or diamagnetic between the poles according to 

 the distance*. 



* To obtain the above result with certainty, it is indispensable, especially if 

 the body to be suspended is light, to avoid giving it the requisite form with 

 instruments of iron (I always use glass), or taking it up with the fingers if they 

 liave previously been in contact with iron and have not been subsequently 

 washed. A piece of dry wood-charcoal, after having been rasped with an iron 

 file, was magnetic under all circumstances. 



