In 1886 Eugen Goldstein used a discharge tube with a hole in the cathode said to be perforatedCathode.
He observed that while cathode rays were streaming away from the cathode, there were coloured rays produced simultaneously which passed through the perforated cathode and caused a glow on the wall opposite to the anode. Thomson studied these rays and showed that they consisted of particles carrying a positive charge. He called them Positive rays.