An experiment by La Fay ([§ 139a]) seems to show that X-rays, in air, after passing through a charged silver leaf, acquire the property of being deflected by a magnet, as are the cathode rays inside the generating or exhausted observing tube, [§ 72a]. If this is confirmed, it would go far to support the theory that these rays are streams of something.
From Sciagraph of Head by Prof. Goodspeed. Nasal Bones appear like Eyelashes.
Inter. Med. Mag., June, ’96.
The cervical vertebræ are distinguishable in the original, but barely so in the half-tone. Fillings are located.
The burden of proof, up to the present, seems to be against any wave theory of the X-rays, for, although they are like the ultra-violet rays in producing fluorescence and in affecting the photographic plate, and have some points of similarity to these rays in their effect upon charged bodies, the X-rays are totally unlike the ultra-violet, in respect to diffraction and interference phenomena. In fact, the absence of such phenomena, if they are really absent, is conclusive proof that the X-rays cannot be wave motions, unless of a wave length extremely short even as compared to waves of light.
Since writing the above, I have seen an account of experiments in relation to diffraction of X-rays, presented to the French Academy by MM. L. Calmette and G. T. Huillier, in which the authors claim to have obtained evidence that diffraction occurs. The following translation of MM. Calmette and Huillier’s paper is taken from the Electrical Engineer, N.Y., for July 22, 1896.
“We have the honor of submitting to the Academy some photographic proofs obtained with the Röntgen rays by means of the following arrangement.”
“Very near the Crookes tube there is a screen “E” (diagram omitted), of brass, perforated by a slit, the width of which has rarely reached a half mm. A second metal screen, E´, is formed of a plate provided with two slits or pierced with a window in which is fixed a metal rod of 1 mm. in diameter. This screen is placed at the distance, a, behind the former. Lastly, a photographic plate, enfolded in two leaves of black paper, is placed at the distance, b, behind the second screen, E´.”
“The following table indicates, for each proof, what is the screen E´ used, and the value of a and b + a:
E´.
| No. | a Cm. | b + a Cm. | |
|---|---|---|---|
| 1. | Rod of 1 mm. in diameter | 5 | 19.5 |
| 3. | Rod of 1 mm. in diameter | 5.5 | 20 |
| 5. | Rod of 1 mm. in diameter | 8.9 | 30 |
| 7. | Two narrow slits, separated by a cylindrical rod of 1 mm. in diameter | ? | ? |