Between 1850 and 1895 the properties of cathode ray (Translation-Cathode Ray, A high speed electron or a stream of them little guys sent out from a cathode into a vacuum tube under the influence of a really strong electric field). The cathode ray discharges were then subjected to almost continuous tests, and a mass of paradox information grew.
Between 1896 and 1898, Sir J.J. Thomson and Sir J.S.E. Townsend, two English physicists, identified a cathode ray as a stream of negatively charges particles now called electrons, were much lighter then the lightest atoms of chemistry.
From the discovery of electrons to the present day the theory of electromagnetism has been confused and mixed with theories of the atomic, sub-atomic and sub-nuclear structure of matter one theory changing another and vice-versa.