The Constitution of Atoms and Molecules

DR. VAN DEN BROEK'S letter (NATURE, May 7, p. 241) contains one or two misapprehensions of the views put forward in my paper (Phil. Mag., April, 1914), and I shall accordingly endeavour to make my meaning clearer. The paper does not purport to show that Dr. van den Broek's hypothesis is incorrect—in fact, in my own belief, it is fundamentally correct, though not necessarily in complete detail—but only to show that it is incompatible with the present form of Bohr's theory. Any atomic theory has two main things to explain in connection with optics—the X-ray spectra investigated by Moseley and the ordinary light spectra of atoms. The fact that coplanar rings are mathematically impossible is conclusive against them, whether on Bohr's theory or the present dynamical one. This must be admitted, in the face of any other evidence which appears to support them. There can be rings of electrons in an atom provided that they are not coplanar, but they must be of the same order of radius. There is only one case in which coplanar rings are possible—the case in which bound electrons do not repel each other, which is considered in detail in a paper to be published shortly, but such a supposition is in complete contrast to the present form of Bohr's theory.