Page:Experimentsnotes00boyl.pdf/565

Rh plac'd never o little beyond it.

5. It has been alo oberved, that the effects of Electrical Attraction are weaken'd if the air be thick and cloudy; and epecially if the South-wind blows: And that Electricks diplay their vertue more faintly by night than by day, and more vigorouly in clear weather, and when the winds are Northerly. All which the Learned Kircherus aerts himelf to have found true by experience; inomuch that thoe bodies that are but faintly drawn when the weather is clear, will not, when 'tis thick and cloudy, be at all moved.

6. We have alo oberved, That divers Concretes, that are notably Electrical, do abound in an effluviable matter (if I may o call it) which is capable of being manifetly evaporated by heat and rubbing. Thus we ee, that mot Reinous Gums, that draw light bodies, do alo, being moderately olicited by heat, (whether this be excited by the fire, or by Attrition or Contui- on)