A. M. Maye)' on 'Hhe electro-tonic state.'' 19 



In his paper on the physical character of the lines of mag- 

 netic force, occurs this remarkable paragraph (Exp. Ees. 3269): 

 " The mutual relation of the magnetic lines of force and the 

 electric axis of power has been known ever since the time of 

 (Ersted and Ampere. This, with such considerations as I have 

 endeavored to advance, enables us to form a guess or judgment 

 with a certain degree of probability, respectmg the nature of 

 the lines of magnetic force. I incline to the opinion that they 

 have a physical existence correspondent to that of their ana- 

 logue, the electric lines; and having that notion, am further 

 carried on to consider whether they have a probable dy nam lo 

 condition, analogous to that of the electric axis to which tliry 

 are so closely, and, perhaps, inevitably related, m which case 

 the idea of magnetic currents would anse ; or whether they con- 

 sist in a state of tension (of the sether?) round the electnc axis, 

 and may therefore be considered as static in their nature. Again 

 and again the idea of an ekctro-imiic state has been forced on 

 my mind ; such a state would coincide and become identihed 

 with that which would then constitute the physical lines of 

 magnetic force." „ , . , . ,x 



We see from the above extracts (all that refer to this subject) 

 that Faraday never gave a formal statement of his conception 

 of the physical condition constituting the electro-tonic state ; 

 but other electricians, including Weber, Neumann and A. De 

 la Eive, have framed hypotheses, more or less probable, to ex- 

 plain this condition, the one most generally received, and in- 

 deed widely copied into existing treatises on physics, is that ot 

 A. De la Rive. (Traite d'Electricit^, t. i, p. 445). I here give 

 this in his own words: and will then describe certain experi- 

 ments of precision, which I have made to test the truth ol his 

 hypothesis. This is the object of making this communication. 

 ''Without having recourse to conceptions and calculations as 

 profound as Weber and Neumann's, I think that we can con- 

 sider induction as the result of the ordinary inductive decom 

 position of the natural electricity of each particle of the induced 

 conductor, by the already separated electricities ol each cor- 

 responding particle of the inductor. In order that this shal 

 take place, we must admit that the propagation of the current 

 takes place by a series of decompositions and recorapositions ot 

 the electricities of the successive molecules, m the same man- 

 ner as takes place with insulating bodies, (referring to i» araclay s 

 theory of inductive action). 4. • +1, iVo^ 



"Let A B be a conductor traversed by a current m the direc- 

 tion from A to B ; the successive particles of which it is com- 

 posed have their natural electricity decomposed, the - turned 

 towards A where is the positive pole of the apparatus, and the 

 + turned towards B where is the negative pole. The electrici- 



