So, when Ben Franklin named them, it was in terms of something like “excess of electricity”. A positive excess of charge, like in the glass he used to define the term, is actually a deficit (negative excess) of electrons, which are the real fluid.
Later on Crooks (I think?) figured out that if he cleared all the air out of a tube with mercury, he could force electrons out of the metal into open space, at the negative cathode end, and at that point they realised it was backwards.
Removed by mod
So, when Ben Franklin named them, it was in terms of something like “excess of electricity”. A positive excess of charge, like in the glass he used to define the term, is actually a deficit (negative excess) of electrons, which are the real fluid.
Later on Crooks (I think?) figured out that if he cleared all the air out of a tube with mercury, he could force electrons out of the metal into open space, at the negative cathode end, and at that point they realised it was backwards.