24 ELECTRICITY IN EQUILIBRIUM. 



point that Lord Stanhope first inferred the true law of the electric 

 attractions and repulsions, although Mr. Cavendish had before 

 ^ted (he same law as the most probable supposition. 



Tlie attraction, thus exerted by an electrified body upon neutral 

 substances, is strong enough, if they are sufficiently light, to over, 

 come their gravitation, and to draw them op from a table at some 

 little distance : upon touching the electrified body, if it is a con. 

 ductor, they receive a quantity of electricity from it, and are 

 again repelled, until they are deprived of th ir electricity by con. 

 tact with some other substance : which, if sufficiently near to the 

 first, is usually in a contrary state, and therefore renders them 

 still more capable of returning, when they have touched it, to the 

 first substance, in consequence of an increased attraction, assisted 

 also by a new repulsion. This alteration has been applied to the 

 construction of several electrical toys ; a little hammer, for ex. 

 ample, has been made to play between two bells; and this instru. 

 ment has been employed for giving notice of any change of the 

 electrical state of the atmosphere. The repulsion which takes 

 place between two bodies, in a similar state of electricity, is the 

 cause of the currents of air which always accompany the discharge 

 of electricity, whether negative or positive, from pointed sub- 

 stances ; each p<rticle of air, as soon as it has received its electri- 

 city from the point, being immediately repelled by it ; and this 

 current has also been supposed to facilitate the escape of the elec- 

 tricity, by bringing a continual succession of particles not already 

 overcharged. 



If two bodies approach each other, electrified either positively 

 or negatively, in ditl< rent degrees, they will either repel or attract 

 each otlier, according to their distance; when they are very 

 remote they exl.ibit a repulsive force, but when they are within a 

 certain distance, the effects of induced electricity overcome the 

 repulsion which would necessarily take place, if the distribution of 

 the fluid remained unaltered by their mutual influence. 



V\'h< n a quantity of the electric fluid is accumulated on one side 

 of a nonconducting substance, it tends to drive oil' the fluid from 

 the other side ; and if thi- fluid is suffered to escape, the remain- 

 ing matter x< rt- its attraction on the fluid which has been imparted 

 to the fir-t side, and allows it to be accumulated in a much greater 

 quantity tlinn could have existed in an equal surface of a conduct, 

 ing substance, la this state the body is said to be charged; and 



