466 Sir Oliver J. Lodge [Feb. 28, 



Hypothetical Structure of Atoms. 



The real facts concerning the quantum, which are the result of 

 observation, suggest when interpreted properly that there are stable 

 electronic orbits in an atom, and that these follow a regular law of 

 succession, analogous perhaps to Bode's law of planetary distances in 

 the solar system. Spectroscopic evidence — the so-called Balmer's 

 series of lines — strongly bears out this idea. For there is what is 

 called K radiation, of highest frequency, apparently due to perturba- 

 tions of the innermost, the most rapid, ring ; L radiation of lower 

 frequency from the next outer ring ; M radiation from a ring out- 

 side this ; and recently there is talk of a J radiation of extra high 

 frequency from a ring still closer to the nucleus— perhaps quite close 

 to it, part of it perhaps — and anyway well within the K ring. 



The frequencies adapted to bring about an atomic catastrophe, or 

 which are emitted during perturbations, are usually high up in the 

 series of X-ray series of vibrations, far above visible light. I assume 

 that these frequencies correspond' with the frequency of orbital 

 revolution, and that the inverse-square law holds good. The more 

 massive the nucleus, the greater must be the frequency of orbital 

 revolution at a given distance, in accordance with Kepler's third law. 

 The square of the frequency multiplied by the cube of the radius of 

 the orbit will be constant for all the orbits of all the atoms of any 

 given substance, and will give the attracting force of the nuclear 

 centre for that substance. 



In other words, this product (or, what comes to the same thing, 

 the radius multiplied by the square of the speed) will correspond to 

 the number of unneutralised positive charges which go to make up 

 the nucleus. It will give in fact the number of the element in the 

 Mendeleeff series. The K radiation frequency from uranium therefore 

 must be exceptionally rapid, because the nucleus is so strong. For 

 hydrogen, whose nucleus is only l/l)2nd of that of uranium, the 

 orbital frequency might be comparatively slow, not higher than the 

 ultra-violet : while the L radiation from hydrogen, it is now thought, 

 may be within the limits of the visible spectrum ; an M series being 

 perhaps in the infra-red. 



But how comes it that hydrogen, with only one electron, can have 

 a K series and an L series and an M series at all ? Bohr's theory 

 suggests that even a single electron may have alternative orbits — not 

 necessarily occupied ; and the spectroscope strongly suggests that the 

 radii of these alternative orbits run as the squares of the natural 

 numbers 



1 4 9 K; 25 etc. 



The frequencies, or reciprocals of periodic times, would then be as the 

 inverse cube of the natural numbers 



1 i tjV -sa etc., 



