<P> In 1729 , Stephen Gray conducted a series of experiments that demonstrated the difference between conductors and non-conductors ( insulators ) , showing amongst other things that a metal wire and even pack thread conducted electricity , whereas silk did not . In one of his experiments he sent an electric current through 800 feet of hempen thread which was suspended at intervals by loops of silk thread . When he tried to conduct the same experiment substituting the silk for finely spun brass wire , he found that the electric current was no longer carried throughout the hemp cord , but instead seemed to vanish into the brass wire . From this experiment he classified substances into two categories : `` electrics '' like glass , resin and silk and `` non-electrics '' like metal and water . `` Non-electrics '' conducted charges while `` electrics '' held the charge . </P>
<P> In 1729 , Stephen Gray conducted a series of experiments that demonstrated the difference between conductors and non-conductors ( insulators ) , showing amongst other things that a metal wire and even pack thread conducted electricity , whereas silk did not . In one of his experiments he sent an electric current through 800 feet of hempen thread which was suspended at intervals by loops of silk thread . When he tried to conduct the same experiment substituting the silk for finely spun brass wire , he found that the electric current was no longer carried throughout the hemp cord , but instead seemed to vanish into the brass wire . From this experiment he classified substances into two categories : `` electrics '' like glass , resin and silk and `` non-electrics '' like metal and water . `` Non-electrics '' conducted charges while `` electrics '' held the charge . </P>
the earliest ideas of charge were the result of experiments by
the earliest ideas of charge were the result of experiments by
Stephen Gray
Stephen Gray