77. CHARGED BODIES DISCHARGED BY CATHODE RAYS.—An insulated metallic plate was charged first with positive electricity and in another experiment with negative electricity. In each instance, the plate was discharged rapidly by the cathode rays as indicated by the electroscope, and the same held true when a wire cage in contact with the aluminum window, surrounded the electroscope and the metallic plate. The effect was stopped by cutting off the cathode rays by quartz .5 mm. thick. The discharge took place, however, through aluminum foil. A magnet was made to deflect the internal cathode rays, whereupon the discharge did not take place, all showing that the discharge of the insulated plate was directly due to those rays. A remarkable occurrence was the accomplishment of _the discharge at a much greater distance than that at which phosphorescence was exhibited_. See also Roentgen’s experiment—who suggested that Lenard had to do with X-rays in this experiment, but thought they were cathode rays. The maximum distance for the discharge was about 30 cm. measured normally to the aluminum window. He caused a discharge of a plate also in rarefied air. He admitted that the experiments were not carried far enough to know whether the effect was due to the action of the cathode rays upon the surface of the window, or upon the surrounding air, or upon the plate. The author could not find in Lenard’s paper any positive or negative proof that he had actually deflected the external cathode rays by a magnet while passing through air or gas at ordinary pressure. He had deflected them while passing through a very high vacuum in the observing tube. Dr. Lodge, who briefly reviewed Lenard’s experiments, expressed the same opinion. See _The Elect._, Lon., Jan. 31, ’96, p. 439. For theoretical considerations of the electric nature of light, the discharge law in the photo-electric phenomena, the simple validity of the discharge law, the occurrence of interference surfaces in the blue cathode light, the cathode rays in the axis of symmetry, the necessary degrees of longitudinal electric waves, the frequency of the cathode rays, and proof of longitudinal character of cathode rays, see Jaumann in _The Elect._, Lon., Mar. 6, ’96; translated from _Wied. Ann._, 571, pp. 147 to 184, ’96, and succeeding numbers of _The Elect._, Lon., which were freely discussed in foreign literature contemporaneously.