And we daily in our experiments electrise bodies plus or minus, as we think proper. [These terms we may use till your Philosophers give us better.] To electrise plus or minus, no more needs to be known than this, that the parts of the Tube or Sphere, that are rubb'd, do, in the Instant of Friction, attract the Electrical Fire, and therefore take it from the Thin rubbing; the same parts immediately, as the Friction upon them ceases, are disposed to give the fire they have received, to any Body that has less.
Benjamin Franklin