122 On AttraSliott and Repulfion. 



its water from the level furface to complete its 

 circle, the level furface being nearer to each 

 circle than they are to each other, and which 

 may be attrafted without either elevating the 

 one or deprefling the other. This water, there- 

 fore, comes between and pufhes them afunder. 



In thefe inftances, repulfion is accounted for 

 by the attraction of intervening fluids, and 

 perhaps the elafticity of the air, eledricity, and 

 all other elaftic fluids may be explained in the 

 fame manner, that is, by fuppofing the mixture 

 of a fyftem of fluids of which fome are capable 

 of permeating glafs and other folids, as light, heat, 

 magnetifm, &c. fo that when air for inftance 

 is condenfed in a vefl'e], the finer fluids are forced 

 through the fides, and fuffer the particles of air 

 to approach nearer together. Or if the ele6lrical 

 duid is forced upon one furface of glafs, a finer 

 fliii^ or fyfliem of finer fluids, which confl:itute 

 its elafticity, are prefl'ed out and rarify the other 

 uninfulated furface : but without new and deci- 

 five experiments, this hypothefis will not be 

 eafily adopted. "Yet, if theory can be fo framed 

 " as really to fuit all the fa6ls, it has all the 

 " evidence of truth that the nature of things can 

 *' admit. And even very lame and imperfedl 

 *< theories are fufficient to fuggefl: ufeful experi- 

 " ments, which ferve to corred thofe theories, 

 " and give birth to others more perfed." 



This 



