his invention was the light which he was 

 able to throw on the laws of magnetism. 

 Thus he found that according to his 

 observations " the magnetical attraction 

 and repulsion are exactly equal to each 

 other." He made and announced the 

 discovery that " the attraction and re- 

 pulsion of magnets decreases as the squares 

 of the distances from the respective poles 

 increase." Yet he modestly remarks 

 that, although his own experiments made 

 the conclusion very probable, "I do not 

 pretend to lay it down as certain, not 

 having made experiments enough yet to 

 determine it with sufficient exactness 1 ." 

 It will be remembered that his contri- 

 bution to magnetism was one of the 

 grounds set forth in the certificate for 

 his election into the Royal Society, and 

 that one of his sponsors was Dr Gowin 

 Knight, the most noted authority of the 

 day on this branch of science. 



1 Treatise of Artificial Magnet^ p. 19. 



75 



