332 DISCOURSE ON THE STUDY 



The force by which its particles repel each other 

 extends to great distances, while its force of ad- 

 hesion to ponderable matter must be regarded as 

 limited in its extent to such minute intervals as 

 escape observation. 



(370.) The conception of a single fluid of this 

 kind, which when accumulated in excess in bodies 

 tends constantly to escape, and seek a restoration 

 of equilibrium by communicating itself to any others 

 where there may be a deficiency, is that which 

 occurs most naturally to the mind, and was accord- 

 ingly maintained by Franklin, to whom the science 

 of electricity is under great obligations for those 

 decisive experiments which informed us respecting 

 the true nature of lightning. The same theory was 

 afterwards advocated by ^Epinus, who first showed 

 how the laws of equilibrium of such a fluid might 

 be reduced to strict mathematical investigation. 

 But there are phenomena accompanying its trans- 

 fer from body to body and the state of equilibrium 

 it affects under various circumstances, which ap- 

 pear to require the admission of two distinct fluids 

 antagonist to each other, each attracting the other, 

 and repelling itself; but each, alike, susceptible of 

 adhesion to material substances, and of transfer 

 more or less rapid from particle to particle of them. 

 These fluids in the natural undisturbed state are 

 conceived to exist in a state of combination and 

 mutual saturation ; but this combination may be 

 broken, and either of them separately accumulated 

 in a body to any amount without the other, pro- 

 vided its escape be properly obstructed by sur- 

 rounding it with non-conductors. When so accu- 



