402 M. P. Riess on the Action of Non-conducting Bodies 



plest case, where an induced body was momentarily touched by 

 a neutral one, and together with others I partially succeeded in 

 controverting the fundamental error according to which the elec- 

 tricity remaining bound or latent in the touched body was said 

 to be either without any action at all, or only to act in a certain 

 direction and within a certain distance. I say only partially 

 succeeded; for although that fundamental error is no longer 

 nakedly and unmistakeably pronounced, yet a multitude of exam- 

 ples show that it is still secretly entertained, and still manifests 

 its prejudicial influence. The whole of the following investiga- 

 tion might be reduced to a few reiterations, were it not advisable 

 to advance experiments against experiments which, in conse- 

 quence of the foregoing error, have obtained a false signification. 



I may here be allowed to remark, that in the discussion 

 on the non-activity of induced electricity, I have been cen- 

 sured for having expressed myself against the term bound or 

 latent electricity as usually employed, and that my proposition 

 to abandon the use of this term has hitherto met with little 

 approval : I think, unjustly. It is not asserted that a wrong 

 meaning is attached to a word, but that in other parts of physics 

 a different interpretation is attached to this word. A quantity 

 of heat is said to be latent when it has no effect upon the ther- 

 mometer, but a quantity of bound or latent electricity has its 

 full effect upon an electroscope. No doubt it is possible to 

 attach a proper interpretation to an inappropriate term, but the 

 necessity- for doing so ought to be avoided. When, of a certain 

 quantity of electricity, a part is said to be latent, we mean that, 

 besides the action of the quantity under consideration, that of a 

 smaller quantity of unlike-named electricity must be taken into 

 account. But to require such an expression to be thus inter- 

 preted appears to me unadvisable. I proceed with the subject 

 of the present memoir. 



In the 11th, 12th, and 13th series of his imperishable Experi- 

 mental Researches, Faraday has occupied himself with induction, 

 and endeavoured to establish the notion that induction is not pro- 

 duced by the action of electricity across space, but that an elec- 

 tric body acts only on the contiguous particles of an insulating 

 medium, and that this action is transmitted from particle to 

 particle of that medium. Thus induction should depend essen- 

 tially upon the nature of the medium which separates the indu- 

 cing from the induced conductor, and on this account the medium 

 is called a dielectric. A long time ago* I showed that this 

 theory was untenable, because it was based upon the assump- 

 tion, proved by experiment to be incorrect, that of the three 



* Vide Repertorium der Physik, 1842, p. 129. 



