Attraction and repulsion 1 1 7 



manner. Let a fluid consisting of particles mutually repelling each other, 

 and whose repulsion extends to considerable distances, be spread uni- 

 formly all over the globe, except in the space A , which we will suppose to 

 contain more than its proper quantity of the fluid. The fluid placed in 

 any space B within reach of the repulsion of A will be repelled from A 

 with more force than it will [be] in any other direction. But as it cannot 

 recede from A without an equal quantity of the fluid coming into its 

 room which will be equally repelled from A, it is plain that it will have 

 no tendency to recede from A , any more than a body of the same specific 

 gravity as water has any tendency to sink in water. Let now the space B 

 be made to contain more than its natural quantity of this fluid, it will 

 then really have a tendency to recede from A , or will appear to be repelled 

 by it, just as a body heavier than water tends to descend in it, and, on 

 the contrary, if B is made to contain less than its natural quantity of the 

 fluid, it will have a tendency towards A, or will appear to be attracted 

 by it. 



215] Let now the space A be made to contain less than its natural 

 quantity of the fluid (as the fluid in B is now repelled from A with less 

 force than it is in any other direction, id est, apparently attracted towards 

 it), if B also contain less than its natural quantity of the fluid it will tend 

 to recede from A , id est, appear to be repelled by it ; but if B contain more 

 than its natural quantity, it will then tend to approach towards A , id est, 

 appear to be attracted by it. 



216] If the electric fluid is diffused uniformly through all bodies not 

 appearing electrical and the repulsion of its particles extends to con- 

 siderable distances, it is plain that the consequences are such as are here 

 described ; but how far that supposition will agree with experiment I am 

 in doubt*. 



* [Note 18, p. 397.] 



