4 DR. FARADAY'S EXPERIMENTAL RESEARCHES IN ELECTRICITY. (SERIES XI.) 



an actual and independent existence as a fluid or fluids, or w^as a mere power of 

 matter, like what we conceive of the attraction of gravitation. If determined either 

 way it would be an enormous advance in our knowledge ; and as having the most 

 direct and influential bearing on my notions, I have always sought for experiments 

 which would in any way tend to elucidate that great question. It was in attempts 

 to prove the existence of electricity separate from matter, by giving an independent 

 charge of either positive or negative power to some substance, and the utter failure 

 of all such attempts, whatever substance was used or whatever means of exciting or 

 evolving electricity were employed, that first drove me to look upon induction as an 

 action of the particles of matter, each having both forces developed in it in exactly 

 equal amount. It is this circumstance, in connection with others, which makes me 

 desirous of placing the remarks on absolute charge first, in the order of proof and 

 argument, which I am about to adduce in favour of my view, that electric induction 

 is an action of the contiguous particles of the insulating medium or di-electric, 



5f ii. On the absolute charge of ma iter, 



1 169. Can matter, either conducting or non-conducting, be charged with one electric 

 force independently of the other, in the least degree, either in a sensible or latent state ? 



1170. The beautiful experiments of Coulomb upon the equality of action of con- 

 ductors, whatever their substance, and the residence of all the electricity upon their 

 surfaces*, are sufficient, if properly viewed, to prove that conductors cannot be bodily 

 charged; and as yet no means of communicating electricity to a conductor so as to 

 relate its particles to one electricity, and not at the same time to the other in exactly 

 equal {\mount, has been discovered. 



1171. With regard to electrics or non-conductors, the conclusion does not at first 

 seem so clear. They may easily be electrified bodily, either by communication (1247.) 

 or excitement ; but being so charged, every case in succession, when examined, came 

 out to be a case of induction, and not of absolute charge. Thus, glass within con- 

 ductors could easily have parts not in contact with the conductor brought into an 

 excited state ; but it was always found that a portion of the inner surface of the con- 

 ductor was in an opposite and equivalent state, or that another part of the glass itself 

 was in an equally opposite state, an inductive charge and not an absolute charge having 

 been acquired. 



1172. Well-purified oil of turpentine, which I find to be an excellent liquid insu- 

 lator for most purposes, was put into a metallic vessel, and, being insulated, was 

 charged, sometimes by contact of the metal with the electrical machine, and at others 

 by a wire dipping into the fluid within ; but whatever the mode of communication, 

 no electricity of one kind was retained by the arrangement, except what appeared 

 on the exterior surface of the metal, that portion being there only by an inductive 

 i*ction through the air around. When the oil of turpentine was confined in glass 



* Memoires de I'Academie, 1786, pp. 67. 69. 72 ; 1787, p. 452. 



