410 Dr. Faraday on the Physical Character of 



nal relation of the poles, and consider them as having no mutual 

 tendency towards or action upon each other, or else admit that 

 there is such an action exerted in or transmitted on through curved 

 lines. To deny such an action, would be to set up a distinction 

 between the action of the north end of a bar upon its south end, 

 and its action upon the south end of other magnets, which, in 

 the face of all the old experiments, and the new ones made with 

 the moving wire (3076.), it appears to me impossible to admit. 

 To acknowledge the action in curved lines, seems to me to imply 

 at once that the lines have a physical existence. It may be a 

 vibration of the hypothetical sether, or a state or tension of that 

 aether equivalent to either a dynamic or a static condition ; or it 

 may be some other state, which though difficult to conceive, may 

 be equally distinct from the supposed non-existence of the line 

 of gravitating force, and the independent and separate existence 

 of the line of radiant force (3251.)*. Still the existence of the 

 state does not appear to me to be mere assumption or hypo- 

 thesis, but to follow in some degree as a consequence of the 

 known condition of the force concerned, and the facts dependent 

 on it. 



3264. I have not referred in the foregoing considerations to 

 the view I have recently supported by experimental evidence, 

 that the lines of force, considered simply as representants of the 

 magnetic power (3117.), are closed curves, passing in one part 

 of their course through the magnet, and in the other part through 

 the space around it. These lines are identical in their nature, 

 qualities and amount, both within the magnet and without. If 

 to these lines, as formerly defined (3071.), we add the idea of 

 physical existence, and then reconsider such of the cases which 

 have just been mentioned as come under the new idea, it will be 

 seen at once that the probability of curved external lines of force, 

 and therefore of the physical existence of the lines, is as great, 

 and even far greater, than before. For now no back action in 

 the magnet could be supposed ; and the external relation and 

 dependence of the polarities (3257. 3263.) would, if it were pos- 

 sible, be even more necessary than before. Such a view would 

 tend to give, but not necessarily, a dynamic form to the idea of 

 magnetic force ; and its close relation to dynamic electricity is 

 well known (3265.). This I will proceed to examine ; but before 

 doing so, will again look for a moment at static electric induc- 

 tion, as an instance of the dual powers in mutual dependence by 

 curved lines of force, but with these lines terminated, and not 

 existing as closed circuits. An electric conductor polarized by 

 induction, or an insulated, unconnected, rectilineal, voltaic bat- 



* See Euler's views of the disposition of the magnetic force ; also of the 

 magnetic fluid, or aether and its streams. Letters, vol. ii. letters 62, 63. 



