420 M. R. Kohlrauscli's Theory of the 



positive, the negative particles in the glass will now lie nearer 

 to G than the positive ones. We will, for the present, assume 

 that no electricity has passed over immediately from the plates 

 to the glass surfaces ; let them now be withdrawn, then the glass 

 will possess an electric moment, whose axis, if we thus call the 

 direction of greatest action, is normal to the surfaces g and h of 

 the glass, and it will therefore exert an independent electro- 

 motive force on any point without these surfaces ; so that if a 

 positively electric particle be now presented to the side g, where 

 the positive plate G formerly stood, it will be attracted, if a nega- 

 tive it will be repelled : on the other side, h, the opposite of this 

 will take place. If we replace the plate G, which has in the 

 mean time been discharged, the potential of the electricities 

 within the glass cannot be zero in reference to a point within 

 the metallic plate ; on the contrary, the electricities in the latter 

 will be separated, so that to restore equilibrium positive elec- 

 tricity will continue to pass towards the side turned to the glass, 

 and negative to flow away (supposing the plate not to be insu- 

 lated), until the potential of the total electricity in reference to 

 the interior of the metallic plate has become zero. Thus on the 

 plate G a quantity of positive electricity, distributed in a deter- 

 minate manner, is now rendered latent. If, instead of the above, 

 we had replaced the plate H after discharging it and connecting 

 it wath the earth, then an exactly opposite condition Avould have 

 been produced, i. e. negative electricity would have been rendered 

 latent on H. If G, however, be first placed in the manner above 

 explained, so that on it the distribution necessary to produce 

 equilibrium can establish itself, then this equilibrium will no 

 longer exist if H be placed in its old position ; for to the action 

 of the glass plate g is now added the similar action of the nega- 

 tive electricity collected on H ; hence it is clear, that, if G and 

 H are connected with the earth, more electricity must be now 

 present on the sides turned towards the glass than when each 

 plate singly stood near the glass, in order that the potential of 

 the whole electricity, in reference to every point within the me- 

 tallic plates, may be zero. 



On the whole, it is clear that nothing will be altered if the 

 plates are brought into contact with the glass ; but if so, then 

 we have a Franklin's plate which is charged and incapable of 

 being discharged. The attraction of the electric moment in the 

 glass is at the same time substituted for the pressure of the 

 free electi'icity on the exterior surface of the coating in a com- 

 monly charged jar, which free electricity determines the discharge. 

 Although it is not here asserted that the distribution of the elec- 

 tricities on the coatings of a plate charged by an electric moment 

 of the glass is the same as that on the coatings of a plate charged 



