106 Dr. Faraday's Experimental Researches in Electricity : 



arrangement as mine or Weber's or Reich's, so diamagnetic 

 polarity would be much more easily distinguished in the same 

 way, and that no indication of that polarity has as yet reached 

 to the force and value of those already given by Brugmann 

 and myself. 



2694. So, at present, the actions represented or typified by 

 iron, by copper and by bismuth, remain distinct; and their 

 relations are only in part made known to us. It cannot be 

 doubted that a larger and simpler law of action than any we 

 are yet acquainted with, will hereafter be discovered, which 

 shall include all these actions at once; and the beauty of 

 Weber's suggestion in this respect was the chief inducement 

 to me to endeavour to establish it. 



2695. Though from the considerations above expressed 

 (2693.) I had little hopes of any useful results, yet I thought 

 it right to submit certain magnecrystallic cores to the action 

 of the apparatus. One core was a large group of symmetri- 

 cally disposed crystals of bismuth (2457.); another a very 

 large crystal of red ferroprussiate of potassa ; a third a cry- 

 stal of calcareous spar ; and a fourth and fifth large crystals 

 of protosulphate of iron. These were formed into cylinders, 

 of which the first and fourth had the magnecrystallic axes 

 (2479.) parallel to the axis of the cylinder, and the second, 

 third and fifth, had the equatorial direction of force (2594. 

 2595. 2546.) parallel to the axis of the cylinder. None of 

 them gave any effect at the galvanometer, except the fourth 

 and fifth, and these were alike in their results, and were de- 

 pendent for them on their ordinary magnetic property. 



2696. Some of the expressions I have used may seem to 

 imply, that, when employing the copper and other cores, I 

 imagine that currents are first induced in them by the domi- 

 nant magnet, and that these induce the currents which are 

 observed in the experimental helix. Whether the cores act 

 directly on the experimental helix or indirectly through their 

 influence on the dominant magnet, is a very interesting ques- 

 tion, and I have found it difficult to select expressions, though 

 I wished to do so, which should not in some degree prejudge 

 that question. It seems to me probable, that the cores act 

 indirectly on the helix, and that their immediate action is 

 altogether directed towards the dominant magnet, which, 

 whether they consist of magnetic or diamagnetic metals, raises 

 them into power either permanently or transiently, and has 

 their power for that time directed towards it. Before the 

 core moves to approach the magnet, the magnet and experi- 

 mental helix are in close relation ; and the latter is situated 

 in the intense field of magnetic force which belongs to the 



