M. E. Edlund on the Nature of Electricity, 85 



the sign + denoting that the action consists of an attraction 

 along the line of junction. 



The action in case 3 will evidently be — -^^ — ^^ ; and that 



ot case 4, + ^' 

 r^ 



Subtracting the algebraic sum of the last two expressions from 



that of the first two, we obtain the result 



The repulsion between two electropositive bodies is therefore 

 proportional to the product of the two excesses divided by the 

 square of the distance. 



We will now consider the case of the two bodies being electro- 

 negative — that is, possessing less than the normal quantity of 

 sether. 



The direct action between the twol {a—h){a — h^ 



bodies will be . 



. . . . 



J- 



The action foreseen 



in case 2 . 





a 3) 



„ 3 . 



{a — b)a 

 • - /2 » 



3i }> 



33 4 . 



• ^ r' 



Subtracting from the sum of the first two expressions the sum 

 of the last two, we obtain for the action in this case the expres- 



sion i-' 



r'^ 



Therefore the bodies repel each other in proportion to the 

 product of the two deficiencies, and in the inverse ratio of the 

 squares of the distances. 



Let us suppose, in the last place, that A is electropositive and 

 B electronegative ; further, let h be the excess of A, and h-^ the 

 deficiency of B. The four cases will give : — 



A- • • • - ^2 



_ , a[a-h^ ^ 

 ^. . . . - + ^^2 , 



Q {a + h)a 



O. . . . = 2 '3 



r^ 

 r^ 



