[ i85 ] 



that diredion, and has fujQScrent liberty to conform to it, points 



to thofe poles. Hence this property is called Polarity. 



a 



The magnetic power is greater or leffer according to the 

 number and homogenity of the particles fimihrly and magne- 

 tically arranged. Hence fmall magnets may be more powerful 

 than a larger, and hence a magnet will attraft a magnetized 

 needle at a greater diftance .than one not magnetized. 



The magnetic power decreafes in a certain ratio of the dif- 

 tance of the particles that exercifc it. Hence it is ftrongeft in 

 the point of contadl, and at the poles, as it is there moft UTij'a- 

 turated^ and weakeft in the central part, which fcparates the two 

 oppofite poles. 



"When a magnet is broken into fmall pieces its power is 

 nearly deftroyed, becaufe though the poles fhould be all of the 

 fame kind, yet the diflance of each from the oppofite pole is fb 

 fmall that their powers countera^ and confequently deliroy each: 

 other. 



If when a needle is attra(Sed by the fouth pole of a magnet 

 a bar of iron be placed on the north pole, the needle is flill 

 more ftrongly attracted, becaufe the iron acquires alio a foutk 

 pole, whofe force is joined to that of the magnet. 



Vol. VI. . A a Ip 



