Page:Popular Science Monthly Volume 49.djvu/121

Rh reflected. The result arrived at, which Prof. Rood says is only to be regarded as a first approximation, was that platinum foil reflects the one two-hundred-and-sixtieth part of the X rays incident on it at an angle of forty-five degrees. Prof. G. Vicentini and Dr. G. Pacher, in a paper read before the Reale Istituto Veneto di Scienze, report having found distinct evidence of an irregular refraction from a parabolic brass mirror.

Regarding the value of these rays in surgery there are at present hardly sufficient data to warrant a positive conclusion. However, a most thorough and profusely illustrated article appeared in the American Journal of the Medical Sciences for March, 1896, entitled The Clinical Application of the Röntgen Rays. It is much the best exposition which this branch of the subject has yet received, and if one can depend on the pictures, the new agent promises to be, if nothing more, at least a great aid to diagnosis.

An interesting commercial application of the rays is announced by Bugnet and Goscard in the Comptes Rendus. "The proofs which we have the honor to submit to the Academy show in juxtaposition silhouettes of genuine diamonds and of imitations, both loose and set. Prolonged exposure soon succeeds in causing the silhouettes of genuine diamonds to disappear, while false diamonds continue to behave like opaque substances. The same procedure has also enabled us to distinguish natural jet from its mineral imitation."

At a meeting of the Royal Society, on February 13th papers on the Röntgen rays were read by Lord Kelvin and Prof. J. J. Thompson. A discussion followed, the general tone of which showed that, although many interesting points have been cleared up, there is still considerable difference of opinion among the authorities regarding fundamentals, and, while extremely valuable experimental work has been done, we are yet far from a final explanation of the origin and properties of this new (?) form of energy.

The following, from an unbeliever, may perhaps be of interest: Ch. V. Zenger says, in speaking of some pictures obtained by Domalip, Professor of Electrotechnics at the Polytechnicum of Prague: "The interesting point is that Domalip has obtained electric images on a plate by means of plates of copper, brass, zinc, lead, and steel. This is, in my opinion, the proof that there is here merely a phenomenon of electric induction producing phosphorescence of the gelatin, and at the same time an electric discharge in the gelatin, and, lastly, the fluorescence of the ambient air, and as in case of the dark discharge of electricity. In my opinion, these are the three agents which determine the decomposition of the silver salts in the sensitive layer. There are no special radiations, no X rays, and no dark light."