NEWTON'S ELECTRICAL EXPERIMENTS. 445 



The recorded electrical experiments made by Newton 

 are few, and are separated by long intervals of time. The 

 earliest one was made in 1675, J when he found that a tele- 

 scope glass, a couple of inches in diameter, mounted in a 

 ring so as to be held about a third of an inch above the 

 table on which it was placed flatwise, would, when rubbed 

 on its upper side, attract bits of paper, etc., lying beneath 

 it; and that the paper would vibrate up and down between 

 glass and table for some time after the rubbing ceased. 

 The Royal Society, to which this was communicated, tried 

 to repeat the experiment and failed. Newton then discov- 

 ered that not only were better results secured by using a 

 larger glass disposed barely a sixth, of an inch distant from 

 the table, but that the nature of the substance with which 

 the glass was rubbed appeared to influence its excitation. 

 This last seems to have impressed him, as well it might, 

 for it was an entirely new observation. He says that he 

 obtained twice as much excitement of the glass when he 

 rubbed it with his gown as he got on rubbing it with a 

 napkin; and he advises the Society not to use linen or soft 

 woolen, but u stuff whose threads may rake the surface of 

 the glass." The Society, curiously enough, obtained the 

 best results by employing a u scrubbing brush made of 

 short hogs' bristles," u the haft of a whalebone knife," 

 and finally resorted to merely scraping the glass with the 

 finger-nails. This experiment of Newton appears to be 

 the first suggestion of the different effects attending the 

 rubbing of the electric with dissimilar bodies, a subject 

 which became of great importance through the subsequent 

 brilliant research of Dufay. 



The principal discovery in magnetism resulting from 

 actual experiment which belongs to the early days of the 

 Royal Society, is the first production of artificial magnets 



1 Horsley: Isaac! Newtoni, Opera. London, 1782, vol. iv., 373. 



