﻿350 Prof. W. M. Hicks on certain Assumptions in the 



3. In dealing with the Zeeman effect on p. 422, Sornmer- 

 £eld adopts Paschen and Back's interpretation of their 

 experiments on the Zeeman effect in the case o£ close 

 multiple lines. This interpretation was based on precon- 

 ceptions as to the nature of the series types in He and 

 Li, which they investigated. I have given * reasons why 

 this interpretation should be modified. On either inter- 

 pretation, however, a consequence follows which appears 

 difficult to explain on the quantum-orbit theory. Take, for 

 example, the case of the helium doublet at 4713 A. Each 

 component in weak fields shows special Zeeman patterns. 

 W4th increasing fields and consequent approximation of 

 certain constituents from each pattern, an interaction occurs 

 of one on the other. Such an effect can only be produced 

 if the two patterns are produced in the same source. Hence 

 the original components of such a doublet must be produced 

 simultaneously in each atomic configuration, whether a 

 magnetic field is present or not. It follows that in radiation 

 there must be simultaneous passages of two electrons, each 

 from its original orbit to its final one. But as the effect 

 takes place at one operation, the total change of energy 

 is passed on to the radiator and emitted as a single mono- 

 chromatic radiation, i. e. no doublet. It might be suggested 

 that the effect could be explained on the hypothesis that the 

 magnetic field affects the mutual possible orbits, and that 

 sometimes one passage occurs and sometimes the other. It 

 is difficult to see, however, how an orbit can be modified by 

 another supposed one which is non-existent, i. e. not being- 

 described at the same time, 



4. This consideration does not affect evidence for the 

 quantum theory, but will serve to illustrate a habit which is 

 somewhat exasperating in reading the writings of many 

 exponents of the quantum theory — viz., the picking up of 

 small and often irrelevant points as charming results of the 

 theory. On p. 300 ff. it is expected that each doublet 

 separation on passage from arc to spark conditions should 

 be magnified in a measure corresponding to the ratio 4N:N, 

 and satisfaction is expressed that in data adduced from 

 corresponding elements in the doublets of group I. and the 

 enhanced doublets of group II. this expectation is fulfilled. 

 The ratios of the separations are reproduced (with Hg : Au 

 added) in the first line of the following : — 



Mg. Ca." Sr. Ba. - 



5-3 3-9 3-4 3-1 



2-24 210 2-03 1-92 



* 'Analysis of Spc^tr.i/ § 7, p. 96. 



Zn. 

 3-5 



ca. 



2-7 



Eu. 



9 



2-5 



2-21 



242 



2-03 



0.]9 



