466 THE INTELLECTUAL RISE IN ELECTRICITY. 



gins to forge the link between the rubbed glass giving 

 light and the rubbed glass attracting scraps of paper, and 

 / suspects that both phenomena are electrical. 



But now new questions crowd upon him. The light 

 appears and the attraction is exercised outside of the glass. 

 The supposed emanations producing both can be cut off 

 by moist air or even by fine muslin, not because of any in- 

 herent property in either air or cloth, but and here he uses 

 a well-known word in modern electrical language because 

 there is an interposition of something- which acts as a u re- 

 sistance. " 



The belief that all these effects are governed by law is 

 uppermost in his mind, and so he says that, " the effluvia, 

 how subtle soever they can be imagined to be, are yet body 

 and matter, and must therefore be liable to the common 

 laws of bodies, which is to be resisted in some proportion to 

 the strength and density of the medium. ' ' At once he seeks 

 to u find in what manner such a motion is propagated and 

 in what figure or sort of track it went along." A chance 

 observation spurs him on. He has held the rubbed tube 

 to his face and felt, with amazement, the electric wind 

 from the dense charge at its extremity, making "very 

 i/ nearly such sort of strokes upon the skin as a number of 

 fine limber hairs pushing against it might be supposed to 

 do." 



As he rubs his tube, the light breaks forth and crackles 

 like green leaves in the fire. The substitution of a solid 

 glass rod for the tube, makes little difference in the effect. 

 Rubbing the tube by hand is awkward, so he arranges a 

 glass cylinder in his lathe and revolves it, noticing now 

 not only the purple light, but again the sensation of a cur- 

 rent or wind striking his finger held near u with some 

 force, being easily felt by a kind of gentle pressure, though 

 the moving body was not touched with it by near half an 

 inch." The object lesson is plain. If whatever that is 

 which seems to come from the glass is so powerful that it 

 can be felt, it ought to be able to influence bodies which 



