446 



BELL SYSTEM TECHXIC.IL JOURXAL 



just j;i\c-n. Imi depends on the stationary state in question: and that 

 m depends on the value of 7 for the stationary state in question. 



Very strong magnetic fields treat a group of stationary states as if 

 they were one single state — as if they were first all fused together into 

 one, and this one then resolved according to equation (8). This is 

 the Paschen-Back effect. It e\idenlly means a great deal. 



The light emitted from a gas exposed to a magnetic field is polarized. 

 Some of the new lines are circularly polarized about the direction of 

 the magnetic field as axis; others are plane-polarized, with the electric 

 vector parallel to the direction of the magnetic field. The lines cor- 

 res[)onding to transitions in wliicli /;; changes by one unit are all 

 polarized in the former way: the liius corresponding to transitions 

 in which in does not change are all jjolari/.id in ihe lailer wa\.-'- 



E III. Iiilcrrclalions of Midliplels and Zeenian Effect 



I insert this section chiefiy for the benefit of such readers as may 

 be preparing for a thoroughgoing study of atomic theory. Others 

 may do well to pass it o\-er, as the statements it contains can scarcely 

 be apprehended with any \ividness, except by the aid of pencil and 

 paper and hours of reiteration. For those who omit this section I 

 will merely say, that the material described in it goes far to show that 

 the numerical \alues which we have been assigning to k and j are 

 not quite arbitrary, but are determined by something fundamental; 

 although the ones heretofore assigned are not necessarih' the most 

 exjiressive. 



I begin with a descri|jtion of the \ arious known systems of stationary 

 states, condensed into Table III. To make this table clear I will 

 exjjlain the fourth line; this line contains the statement that a "quartet 

 SNstem" of stationary states consists of an s-coliuitn of single le\els, a 

 />-column of groups of three levels each, and a ^/-column, an /-colinnn. 

 and additional columns of groups of four le\ els each. 

 TABLE ill 



Name of System 



/' 



/" 



Siiiulet. . 



Doublet. 



Triplet. 



yuartet . 



Quintet 



.St-xtft 



Septet 



Octet 



" The effect of a macnetir field on resonance-radiation, discovered by Wood ami 

 Elicit, will be dcscrilird in the Second Part. 



