126 ESSAYS AND OBSERVATIONS 



fedl : Yet there are a multitude of fa(5^s 

 which indicate a mechanifm by means of 

 fome effluvia ; particularly the new me- 

 thod of making artificial magnets by at- 

 trition, and the well known experi- 

 ment, in which an iron rod is prefented 

 to a magnetic needle, the fame end being 

 made to attradl, fometimes one pole and 

 fometimes another, by only changing the 

 pofition of the rod, or inverting it upfide 

 down ; and much more by flriking upoa 

 it with a hammer, or beating it againft 

 the ground. F,le(f^ricity is another more 

 palpable inftance of the fame fort. That 

 a fluid is concerned in producing the ap- 

 parent attradlions and repulfions, and 

 other more aftonifhing effects of the elec- 

 tric globe, can hardly be doubted, how- 

 ever difficult it may ftill be to defcribe the 

 Jaws to which it is fubjecled in its opera- 

 tions. Why then {hould it be accounted 

 " whimfical" or unphilofopical to de-^ 

 mand a caufe for the attradlive power of 

 gravity? Though all the mechanical ac- 

 counts hitherto given of the caufe of 

 gravity fhould be found unfatisfa(5lory, 



