3 * 2 P0/tf/ j * ttra 51 mojl forcibly. [Book IV. 



to notice before the conclufion of this branch of the 

 lubjecl, and that is, that it is more forcibly attracted 

 by points than by balls or any blunt or rounded fur- 

 faces. This may be demonftrated by a variety of ca-fy 

 experiments, and may be feen by prefenting a metal 

 ball at a given diftance to a conductor in the act of 

 being charged, when it will be found that a metal 

 point prefented at a much greater diftance will draw 

 off the whole of the electrical matter from the con- 

 ductor. In the one cafe alfo (the point) the electri- 

 city goes off invifibly, and without noife ; in the other 

 cale there is both a flafli and a report. 



With refpect to the modes employed by electricians 

 for the accumulation of the fluid, it will be neceffary 

 to confider them in a diftinct chapter j but previous 

 to this a few particulars muft be dated relative to 

 wnat tt termed pofitive and negative electricity. 



