Hint: While conducting experiments on the gas discharge, in\[1886\], German Physicist, E. Goldstein, discovered that if the cathode used is perforated, luminous streams appeared in the tube behind the cathode. These streams were called canal rays.
Complete answer: A canal ray is a beam of positive ions that is created by certain types of gas-discharge tubes. They were first observed in Crookes tubes during experiments by the German scientist Eugen Goldstein, in$1886$. Later work on anode rays by Wilhelm Wien and J. J. Goldstein utilized a gas discharge tube which had a punctured cathode. At the point when an electrical potential of a few thousand volts is applied between the cathode and anode, faint iridescent "beams" are seen stretching out from the openings toward the rear of the cathode. These beams will be light emissions moving toward a path inverse to the cathode beams, which are surges of electrons which push toward the anode. Goldstein called these positive beams Kanalstrahlen, canal rays, since they were created by the openings or directs in the cathode. Properties of canal rays: They are the streams of positive ions of the gas enclosed in the discharge tube. The mass of each ion is nearly equal to the mass of the atom. They are deflected by electric and magnetic fields. Their deflection is opposite to that of cathode rays. They travel in straight lines. The velocity of canal rays is much smaller than the velocity of cathode rays. They also affect photographic plates. These rays can produce fluorescence and ionize the gas through which they pass.
Note: An anode ray ion source typically is an anode coated with the halide salt of an alkali or alkaline earth metal. Application of a sufficiently high electrical potential creates alkali or alkaline earth ions and their emission is most brightly visible at the anode. Light producing process, called fluorescence, causes a glow in the region where the ions emerge from the cathode.