I remember reading an early book on the topic where the author describes two kinds of electricity: "glass-electricity" and "resin-electricity". The experiments

I remember reading an early book on the topic where the author describes two kinds of electricity: "glass-electricity" and "resin-electricity". The experiments seemed to involve rubbing either glass or hardened resin (amber?) with something. The author (it wasn't Franklin) concluded, after a series of experiments, that this produces two different "kinds" of electricity which seem to cancel each other out. Edit: I think I found the author: https://en.wikipedia.org/wiki/Charles_Fran%C3%A7ois_de_Cisternay_du_Fay https://en.wikipedia.org/wiki/Charles_Fran%C3%A7ois_de_Ciste... His wikipedia page seems to confirm he discovered there are two kinds of electricity and named them "vitreous" and "resinous".