of €Ietfricttp* ii 



plac ! d never fo little beyond it, 



5. It has been alfo obferved, that 

 the effe&s of Ele&rical Attra&ion 

 are weaken'd if the air be thick and 

 cloudy 5 and efpecially if the South- 

 wind blows : And that Eleftricks dis- 

 play their vertue more faintly by 

 night than by day , and more vigo- 

 rously in clear weather , and when 

 the winds are Northerly. All which 

 the Learned Kircherus afferts himfelf 

 to have found true by experience i 

 infomuch that thofe bodies that are 

 but faintly drawn when the weather 

 is clear j will not, when 'tis thick 

 and cloudy, be at all moved. 



6. We have alfo obferved^ That 

 divers Concretes^ that are notably 

 Eledrical, do abound in an effluvi- 

 able matter ( if I may fo call it ) 

 which is capable of being manifeft- 

 ly evaporated by heat and rubbing. 

 Thus we fee , that moft Refinous 

 Gums, that draw light bodies ^ do 

 alfo, being moderately folicited by 

 heat, ( whether this be excited by 

 the fire, or by Attrition or Gontufi- 



on 3 



