Rays of Positive Electricity And Their Application to Chemical Analyses

RAYS OF POSITIVE ELECTRICITYThe positive rays were discovered by Goldstein in 1886.1 His apparatus is represented in Fig. 1 ; the cathode K which stretched right across the tube r was a metal plate through which a number of holes were drilled, the diameter of the holes being considerably less than the thickness of the plate ; the axes of the holes were at right angles to the surface of the plate; the anode a was at the end of the lower part of the tube. The pressure of the gas in the tube was so low that when the electrodes K and a were connected with the terminals of an induction coil and a discharge passed through the tube, the dark space below the cathode was well developed. Under these circumstances Goldstein found that slightly diverging bundles of a luminous discharge streamed through the holes in the cathode into the upper tube. The colour of the light in these bundles depended on the kind of gas with which the 'tube was filled: when it was air the light was yellowish, when iTab