Edison observes electric current flowing through vacuum from heated filament to metal plate.

FitzGerald proposes generating Maxwellian radio waves using oscillating electric spark gap discharges.

Proposed generating radio waves using high-frequency LC oscillating spark discharges.

Patented Edison Effect, discovering electron emission across vacuum.

Arrhenius discovers that salts spontaneously dissociate into free electric ions when dissolved in water.

Proved electrolytes spontaneously dissociate into free ions in water.

Stoney calculates elementary electric charge (e) from Faraday electrolysis and introduces the term "Electron".

Helmholtz delivers the Faraday Lecture, proposing that electricity consists of elementary electric atoms.

Michelson invents the amplitude-splitting interferometer in Potsdam, testing luminiferous ether drift.