342 Reflections on the Inadequacj/ of the principal Hypoi hoses 



contradictions ; and nothing can be so effectnr.lly subversive of 

 his whole system as the consequences which flow from it. It 

 will be necessary to trace but a tew of those instances in which 

 facts are at variance with this principle. A ])ody sl-ghtly posi- 

 tive, and one strongly so repel each other ; the powers differing 

 in density. A body slightly negative rejiels one strongly so, the 

 powers also differing in density. A body positive differs from 

 one negative only in density, ■ and yet tliey attract each other 

 violently. Suppose the interval between the minimum and 

 maximum of density to be divided into seven terms, and the 

 medium term 4 to be the natural density of ail bodies : 1 and 2 

 repel, 2 and S repel, but 3 and 4 attract ; 4 and 5 attract, but 

 5 and G, or 6 and 7 repel. Again, 7 violently repels 5 with the 

 difference 2, but when the difference increased by 1 more 

 (total difference 3), a violent attraction takes place. From all 

 this it is plain that the phjenomcna of attraction and repulsion 

 are completely at variance with the tlieory : and from what fol- 

 lows this will appear still more striliingly. 



To explain why a body positively electrified attracts one ia 

 the negative state, recourse is bad to that princijile which sup- 

 poses the attraction of electricity to all matter. For the por- 

 tions of matter which are deprived of their natural quantity 

 must be attracted by any bodv which contains an excess : we 

 shall see how far the explanation is applicable. 



From the nature of an equilibrium it must be su])posed, as 

 has already been observed, that every particle of electricity is 

 attracted by a certain number of particles of matter in a given 

 body: let us say one to one. Franklin conceives that a strong 

 pov.er will repel the natural quantity in any body. If then a 

 body A contain 10 particles of matter attracted by 10 of 

 electricity, that body is in the natiu-al state. If a body B con- 

 taining 10 particles of matter, and 20 of electricity be brought 

 near A, it ought to happen, from the principle in question, that 

 a repulsion would talce place. If one particle of electricity be 

 taken from A, one particle of matter is left vacant, which must 

 be attracted by B. But the latter attraction is exerted towards 

 one particle only of matter; the repulsion is exerted tov\ards 9 ; 

 the bodies consequently vStill repel : and no attraction can take 

 place until the vacant particles exceed in number those which 

 possess their natural ijuantity of eiectricitv. Such are the con- 

 sequences which ought to happen, were the hypotheses well 

 founded : it is plain how much they disagree vvith facts. Ex- 

 periment shows that a body however slightly negative, will be 

 attracted by one that is positive. In the foregoing example, if 

 the body A in its natural state be presented to B with its in- 

 creased power, no attraction ought to take place, as there is no 



vacant 



