FARADAY'S CONCEPTION OF ELECTRICITY. 243 



between the sun, the planets, and then- satellites. It is known how, 

 with much caution and even reluctance. Sir Isaac Newton himself pro- 

 posed his grand hypothesis, which was destined to become the first 

 great and imposing example, illustrating the power of true scientific 

 method. 



But then came Oerstedt's discovery of the motions of magnets 

 under the influence of electric currents. The force acting in these 

 phenomena had a new and very singular character. It seemed as if it 

 would drive a single isolated pole of a magnet in a circle around the 

 wire conducting the current, on and on without end, never coming to 

 rest. Faraday saw that a motion of this kind could not be produced 

 by any force of attraction or repulsion, working from point to point. 

 If the current is able to increase the velocity of the magnet, the mag- 

 net must react on the current. So he made the experiment, and dis- 

 covered induced currents ; he traced them out through all the various 

 conditions under which they ought to appear. He concluded that 

 somewhere in a part of the space traversed by magnetic force there 

 exists a peculiar state of tension, and that every change of this tension 

 produces electro-motive force. This unknown hypothetical state he 

 called provisionally the electrotonic state, and he was occupied for 

 years and years in finding out what was this electrotonic state. He 

 discovered at first, in 1838, the dielectric polarization of electric insu- 

 lators, subject to electric forces. Such bodies show, under the influ- 

 ence of electric forces, phenomena perfectly analogous to those ex- 

 hibited by soft iron under the influence of the magnetic force. Eleven 

 years later, in 1849, he was able to demonstrate that all ponderable 

 matter is magnetized under the influence of sufliciently intense mag- 

 netic force, and at the same time he discovered the phenomena of dia- 

 magnetism, which indicated that even space, devoid of all ponderable 

 matter, is magnetizable ; and now, with quite a wonderful sagacity 

 and intellectual precision, Faraday performed in his brain the work of 

 a great mathematician without using a single mathematical formula. 

 He saw with his mind's eye that, by these systems of tensions and 

 pressures produced by the dielectric and magnetic polarization of space 

 which surrounds electrified bodies, magnets or Avires conducting elec- 

 tric currents, all the phenomena of electro-static, magnetic, electro- 

 magnetic attraction, repulsion, and induction could be explained, with- 

 out recurring at all to forces acting directly at a distance. This was 

 the part of his path where so few could follow him ; perhaps a Clerk 

 Maxwell, a second man of the same power and independence of intel- 

 lect, was necessary to reconstruct in the normal methods of science 

 the great building, the plan of which Faraday had conceived in his 

 mind and attempted to make visible to his contemporaries. 



Nevertheless, the adherents of direct action at a distance have not 

 yet ceased to search for solutions of the electro-magnetic problem. 

 The present development of science, however, shows, as I think, a 



