Most people give the credit to Benjamin Franklin for discovering electricity, well that is not necessarily true. Franklin was given credit for the discovery through his well-know experiment of flying a kite during a thunderstorm. But the true credit should partly go to the pre-Socratic philosopher, Thales of Miletus, who wrote about the charging amber on rubbing it.
Electricity is very conductive with most metals.
It is especially conductive with silver and pure water
Rubber is electricity resistant, that's why cords are wrapped in it