■Hhe electro-tonic state.'" 



Art. IY. — On the physical condition of a closed circuit contiguous 

 to a permanent and constant Voltaic current; or, on " the electro- 

 tonic state ;" bj Alfred M. Mayer, Ph.D. 



In 1831, after Faradaj had made his brilliant and uneqiialed 

 discoveries of Voltaic and magnetic induction, he gave, in his 

 first series of experimental researches, a section on a "New 

 electrical State or Condition of Matter;" which he designated 

 as the electro-tonic state. This can, in a few words, be explained 

 as a certain state of electrical tension produced in a closed 

 metallic circuit by the proximity of another circuit, through 

 which circulates an electric current. The latter circuit being 

 broken, this tension evinces itself in producing, during its dis- 

 appearance, an electric wave in the closed circuit, similar in 

 character, but opposite in direction, to the one produced on 

 forming the contiguous electric current. 



Faraday, with his habitual philosophic reserve, hesitating to 

 give a formal enunciation of any hypothesis as to the electrical 

 or molecular condition of the wire during this state, says, (Exp. 

 Rea 71) "this peculiar state appears to be a state of tension, 

 and may be considered as equivalent to a cuiTent of electricity, 

 at least equal to that produced either when the condition is in- 

 duced or destroyed." But in the celebrated Bakerian lecture 

 which he delivered in Jan., 1832, he reluctantly releases his 

 mind from this opinion, and says, (Exp. Bes. 231 ; 242), " The 

 law under which the induced electric current excited m bodies 

 moving relatively to magnets, is made dependent on the inter- 

 section of the magnetic curves by the metal being thus rendered 

 more precise and definite, seem now even to apply to the 

 cause in the first section of the former paper ; and by render- 

 ing a perfect reason for the effects produced, take away any for 

 supposing that peculiar condition which I ventured to call the 

 electro-tonic state. * * * * Thus the reasons which in- 

 duce me to suppose a particular state in the wire have disap- 

 peared ; and though it still seems to me unlikely that a wire at 

 rest in the neighborhood of another carrying a powerful elec- 

 tric current is entirely indifferent to it, yet I am not aware of 

 any distinct facts which authorize the conclusion that it is m a 

 particular state." 



In Dec, 1834, however, we see with what reluctance he ga\'e 

 up his first opinion, for he thus writes (Exp. Res. 1114) m ref- 

 erence to " the influence by induction of an electric current on 

 itself, and on the inductive action of electric currents generally. 

 "Notwithstanding that the effects appear only at the making 

 and breaking of contact, (the current remaining unaftected, 

 seemingly, in the interval), I cannot resist the impression that 



Am. Jour. Sci.— Third Series, Vol. I, No. 1.— Jan., 1871. 



