r in ] 



XXIV. A Rotation for Zeeman Patterns. 

 By W. M. Hicks, F.R.S.* 



THE convenience of a generally recognized and concise 

 notation to represent the configuration of the com- 

 ponents when a spectral line is decomposed in a magnetic 

 field is evident. I have found the following very useful for 

 entering on handlists of spectral lines, and offer it as a 

 suggestion for general use. Range has shown that the 

 displacements of the various components in a given field 

 are multiples or submultiples of a constant unit. The wave- 

 number displacement chosen by him as the unit is that of 

 what is commonly called the normal triplet — the theoretical 

 value for an electron revolving round a centre of attraction. 

 It is convenient to take one third of this, in order to avoid 

 the frequent appearance of fractions. Using the very careful 

 determination from Cd and Zn by Fraulein Stellenheimer f 

 working in Prof. Paschen's laboratory, this constant is given 

 by 10~~°d\/\ 2 K = 1*584. As the displacements take place in 

 general symmetr cally on both sides of the undisplaced line, 

 it is only necessary to tabulate those on each side and to 

 indicate the distances as multiples of the unit. From 

 analogy with the usual diagrammatic method of indicating 

 a Zeeman pattern, the displacement of lines vibrating parallel 

 to the field may be written as a numerator, whilst those 

 perpendicular are indicated in the denominator. Thus the 



normal triplet would be written ^ or printed | 3. In cases 



where it is desirable to indicate relative intensities subscript 

 figures may be attached, or — for printed matter where such 

 subscripts are inconvenient — by figures in brackets, as is done 

 below. 



With this notation the patterns for the various kinds of 

 series are then represented as follows: — 



Doublets. 

 s i} I-V S 2 , P 2 . 



2 | 6.10, 4 | 8. 



D 12 . D u . D«. 



5 | 10, | 6£, | 5. 



The satellite pattern (D 12 ) does not seem to be the same 



* Communicated by the Author, 

 •f Ann. der Phys. xxir. p. '2&±. 



