on certain Theoretical Opinions '. 55 



(1667). It does not even include the origination of the de- 

 veloped or excited state of the power or powers ; but taking 

 that as it is given by experiment and observation, it con- 

 cerns itself only with the arrangement of the force in its com- 

 munication to a distance in that particular yet very general 

 phenomenon called static induction (1668.). It is neither the 

 nature nor the amount of the force which it decides upon, 

 but solely its mode of distribution. 



iii. Bodies whether conductors or non-conductors can be 

 charged. The word charge is equivocal : sometimes it means 

 that state which a glass tube acquires when rubbed by silk, 

 or which the prime conductor of a machine acquires when 

 the latter is in action ; at other times it means the state of a 

 Leyden jar or similar inductive arrangement when it is said 

 to be charged. In the first case the word means only the 

 peculiar condition of an electrified mass of matter considered 

 by itself, and does not apparently involve the idea of induc- 

 tion ; in the second it means the whole of the relations of two 

 such masses charged in opposite states, and most intimately 

 connected by inductive action. 



iv. Let three insulated metallic spheres A, B and C be 

 placed in a line, and not in contact ; let A be electrified po- 

 sitively, and then C uninsulated ; besides the general action of 

 the whole system upon alt surrounding matter, there will oc- 

 cur a case of inductive action amongst the three balls, which 

 may be considered apart, as the type and illustration of the 

 whole of my theory : A will be charged positively ; B will 

 acquire the negative state at the surface towards A, and the 

 positive state at the surface furthest from it ; and C will be 

 charged negatively. 



v. The ball B^will be in what is often called a polarized 

 condition, i. e. opposite parts will exhibit the opposite elec- 

 trical states, and the two sums of these opposite states will be 

 exactly equal to each other. A and C will not be in this po- 

 larized state, for they will each be, as it is said, charged (iii.), 

 the one positively, the other negatively, and they will present 

 no polarity as far as this particular act of induction (iv.) is 

 concerned. 



vi. That one part of A is more positive than another part 

 does not render it polar in the sense in which that word has 

 just been used. We are considering a particular case of in- 

 duction, and have to throw out of view the states of those parts 

 not under the inductive action. Or if any embarrassment still 

 arise from the fact that A is not uniformly charged all over, 

 then we have merely to surround it with balls, such as B and 

 C, on every side, so that its state shall be alike on every 



