E. Goldstein constructed a special tube known as a canal rays tube. This tube usually have two chambers would just separated by a perforated metallic disc severed as cathode of the this charge tube. The space between anode and cathode of the this charge tube contain a small number of residual gas molecules. The anode and cathode are supply high voltage. The electrons emitted from the cathode collapse with the residual gas molecules. This collapse accelerated towards knock an electrons out of each gas atoms generating positive charge ions which are accelerated to (ฟังไม่ออก) the cathode and they pass to the whole in the cathode. Producing a beam