* 

 130 ELECTRICITY; [Lesson xxr. 



This Electric Fluid, it is supposed, moves with 

 great ease in those bodies that are called conductors, 

 but with extreme difficulty and slowness in the 

 pores of Electrics ; whence it comes to pass, that 

 all Electrics are impermeable to it. Jt is farther 

 supposed, that Electrics contain always an equal 

 quantity of this fluid, so that there can be no sur- 

 charge or increase on one side, without a propor- 

 tionable decrease or loss on the other, and vice 

 versa ; and as the Electric does not admit the pas- 

 sage of the fluid through its pores, there will bean 

 accumulation on one side, and corresponding de- 

 ficiency on the other. Then when both sides are 

 connected together by proper conductors, the equi- 

 librium will be restored by the rushing of the re- 

 dundant fluid from the overcharged surface to the 

 exhausted one. Thus also, if an Electric be rub- 

 bed by a conducting substance, the Electricity is 

 only conveyed from one to the other, the one giving 

 what the other receives ; and, if one be electrified 

 positively, the other will be electrified negatively,. 

 unl< ss the loss be supplied by other bodies connect- 

 ed with it. This theory serves likewise to illustrate 

 the various phenomena and operations in the 

 science of Electricity : thus, bodies differently elec- 

 trified will naturally attract each other, till they 

 mutually give and receive an equal quanti'y of the 

 EKctric Fluid, and the equilibrium is restored be- 

 tween them. B.eccaria supposes that this effect is 

 prodncfd-by the Electric Matter making a vacuum 

 in its passage, and the contiguous air afterwards 

 collapsing, and so pushing the bodies together. 



It 



