NON-REFLECTION OF X-RAYS. (_Elect. Eng._, Feb. 19, ’96, p. 190. Apparently extracted from the daily press.)—That the X-rays were only slightly reflected (Roentgen, § 81., and even when very powerful (Tesla, § 146., was determined in a severe manner by Edison. The first experiment consisted in employing a funnel 8 inches long and 3/4 inch at the smaller end. The discharge tube was in the larger end, and the photographic plate across the smaller end. After experiment and development, the plate showed overlapping circular images, which would indicate reflection from the inner surface of the funnel. This may have been due to a jarring vibration of the funnel. Therefore, he carried the experiment further by using a funnel 9 feet long. The plate did not indicate any signs of reflection, as it merely became generally fogged. The material of the tube is not named, but if of brass or other impermeable metal, it is thought that his experiment would have shown a result agreeing with that of others herein. Again, the reporter may have been in error. Also, the rays may have been very weak, as the experiment was performed when Edison first started to investigate the subject. 136. X-RAYS NOT YET OBTAINABLE FROM OTHER SOURCES THAN DISCHARGE TUBES.—Edison exposed covered plates to the direct sun-light at noon for three or four hours; no photographic impression; also to electric sparks in open air, of twelve or more inches in length; no clouding even of the photographic plate. Profs. Rowland et. al., of the Johns Hopkins University, in a contribution to _Electricity_, Apr. 22, ’96, p. 219, confirmed this point by stating: “As to other sources of Roentgen rays, we have tried a torrent of electric sparks in air from a large battery, and have obtained none. Of course, coins laid on or near the plate, under these circumstances, produce impressions, but these are, of course, induction phenomena.” (See Sandford and McKay’s Fig. p. 20). “As to sun-light, Tyndall, Abney, Graham, Bell and others have shown that some of the rays penetrate vulcanite and other opaque objects.” Poincaré, at an early date, advanced the hypothesis that X-rays are due to phosphorescence, whether produced by electrical or other means. _Elect. World_, Digest., Mar. 28, ’96, p. 343, where it is also stated that Chas. Henry thought a certain experiment of his own was in favor of the hypothesis. The experiment was performed with a phosphorescent material which had been exposed to the light and then brought into darkness. Niewengloswski inferred, from an experiment, that phosphorescent bodies increase the penetrating power of sun-light. Tesla admitted the possibility of the radiation of X-rays from the sun. In an article describing important experiments in the _Elect. Rev._, N.Y., Apr. 22, ’96, p. 207, he stated: “I infer, therefore, that the sun-light and other sources of radiant energy must, in a less degree, emit radiations or streamers of matter