Mr. Laming on the primary Forces of Electricity. 47 



of receding from each other, the two balls will, as shown by 

 Mr. Harris, be brought together*. 



41. We may next inquire into the sufficiency of the new 

 theory to explain the various circumstances under which dis- 

 charges of free electricity may be made to take place between 

 plus conductors and their compensating bodies. 



As action and re-action are in all cases equal, it is evident 

 that the minus common matter in a negatively electrical body 

 must as forcibly attract the free electricity in a plus body as 

 it is itself attracted by it ; and therefore were the cases parallel 

 in other respects also, the phaenomena of electrical attraction 

 and electrical discharges would at all times be simultaneous. 



42. In the case of electrical attractions we certainly have 

 a retarding force in the gravity of one or both of the at- 

 tracted bodies, and frequently in the gravity of materials to 

 which they are attached; and this retarding force may be 

 sufficiently great to overcome the attractive force at any di- 

 stance, however small. On the other hand, either one or 

 both of the attracted bodies may be so free to move as to op- 

 pose a retarding force indefinitely minute ; and then they will 

 be brought together through a distance almost, though never 

 quite, so great as that through which under the circumstances 

 their compensating influence extends. 



43. Now unless there were a retarding force to electrical 

 discharges, these would occur at the extreme distance at which 

 the major attraction acts, or in other words, at which com- 

 pensation becomes established ; and thus the discharging di- 

 stances being greater than the distances at which visible at- 

 traction is effected, the latter phsenomenon never could take 

 place. It is obvious therefore that electrical discharges are 

 restrained by some retarding force ; and this is supplied in 

 the minor attraction acting between the free electricity in the 

 plus body, and the electrical equivalent which is natural 

 to it. 



44. Since then the minor electrical attraction in every plus 

 conductor is a retarding force to the discharge of its free 

 electricity, it will act with less effect upon any particular elec- 

 trical atom as it is further removed from the general mass ; 

 and therefore a plus charge may be drawn off with a less 

 amount of major attraction, and consequently at greater di- 

 stances, from projecting points and angles than from any 

 other surfaces. Hence the great freedom with which elec- 

 tricity issues from a point to its compensating atmosphere; 

 and hence also the escape of the electrical spark towards a 

 conductor, at greater distances through the compensating at- 



• Phil. Trans. 1836, p. 431. 



