The Nature of Röntgen Rays

Abstract

IN NATURE of January 23 (p. 270) Prof. Bragg defends his neutral pair theory of X-rays, and his explanation of scattering and polarisation on this theory, against a criticism which I made in a recent letter (NATURE, October 31, 1907). Though he appears to have enlarged his conception of the possible function of the ether pulse in X-ray phenomena, he contends that my one assumption is unjustifiable, consequently is of no value as a critical test. Prof. Bragg had assumed that a pair revolves in a plane containing its direction of translatory motion, that when incident on light atoms it is liable to be taken up only by an atom revolving in the same plane, sometimes to be ejected again, and that if ejected again it continues to rotate in the same plane. My assumption in calculating the distribution of intensity of secondary radiation was that after being taken up by an atom its liability to be ejected again is equal in all directions in that plane. This does not appear quite so unjustifiable as, from Prof. Bragg's letter, one would judge it to have been.