Discovery of PROTON

Atom as whole is neutral because material bodies are electrically neutral. After the discovery of electrons (the negatively – charged particles) attempts were made to discover the positively–charged constituents of the atom. In 1886, Goldstein used a discharge tube with a perforated cathode, He observed luminous rays passing backwards through the perforation in the cathode. These Rays produced flashes on the walls of glass coated with zinc sulphide behind the perforated cathode. These rays were shown to consist of positively charged particles by Thomson and were called Positive Rays. Since these seem to be originating from the anode, these rays were also called Anode Rays. These rays are also called Canal Rays.