GENERAL ACCOUNT OF COMMON PHENOMENA 7 



This gives us an additional reason for ascribing the algebraic 

 signs + and to the two kinds of electrification. Not only do 

 they show opposite mechanical actions, but when they come together 

 in proper proportion the resultant effect is non-electrification. 



We may describe induction, perhaps, more easily by materialising 

 our conception of electrification, regarding it as something which 

 we call electricity, in addition to and possessed by the matter, 

 rather than of as a condition of the matter. A neutral body we may 

 regard as possessing amounts of the two electrifications practically 

 unlimited and so mixed together as to neutralise each other. Each 

 electricity must be endowed with an action of repulsion on its own 

 kind and of attraction on the opposite kind. This, we must note, is 

 not a repetition of the statement on p. 2 of the mechanical action 

 between electrified bodies. One gives the nature of the force 

 between portions of electrified matter tending to move matter ; the 

 other gives the actions between electrifications tending to move 

 electricity even though the matter is kept at rest. 



Using this new conception, we may say that the + electricity 

 on A (Fig. 5) decomposes the neutral mixture on B, drawing 

 the opposite nearer to itself and repelling the like -f? which we 

 may term complementary, away to the other end. 



This mode of description is merely provisional. We shall see 

 later that we must suppose the medium round the electrified bodies 

 to take part in the phenomena, and when we try to assign to the 

 medium iU share in the action the above conception of electrifica- 

 tion ceases to be adequate. But if we use it, not as a hypothesis 

 but rather as an illustration to aid us for a time in arranging the 

 ascertained facts of electric induction, it will be at least quite 

 harmless. 



If we touch B with the finger or with any other conductor, so 

 breaking down its insulation, B becomes part of the general 

 conducting system, consisting of the table, floor, walls, and so on, 

 and then either the positive electricity can get further away from 

 A and so leaves B, or A draws up towards itself more negative 

 from the surrounding conductors on to B. Whichever process 

 takes place the effect is the same, viz. B loses all its positive 

 charge and is only negatively electrified. If now we break the 

 communication with the earth, B retains this electricity even if A is 

 removed ; on the removal of A the electricity on B is redistributed, 

 and negative will be found on either end of it. 



We may now explain the action of an electrified body in the 

 fundamental experiment of the attraction of light bodies, such as 

 bits of paper or bran. The electrified body acts by induction on 

 these light bodies. electrifying their nearer surfaces with the kind 

 opposite to its own, the complementary charge of the same kind 

 going cither to the further side or passing away to the table or 

 whatever the particles rest upon. The bodies thus oppositely 

 electrified attract each other and the particles fly to the electrifiecl 



