382 



DE. W. M. HICKS : A CRITICAL STUDY OF SPECTEAL SERIES. 



Here however no such certain conclusions can be drawn. They may enter as links. 

 Although their true connection may ultimately be definitely settled the doubt as to 

 whether they give true or false scents renders the task of unravelling most 

 bewildering. 



In about the region to be expected we find the set 



(l) 1988072 1778-42 (5) 2165914 815'30 (10) 22474'44 



showing from their separations and order of intensities an indubitable satellite set of 

 D 3 type. Below these come a number of indubitable doublets of D 2 type, and then a 

 number of strong lines of D u type. There are also in this region an extremely large 

 number of lines with separations between 1780 1785 corresponding to the enlarged 

 links already found in the KrD spectrum. This portion of the spectrum is set out 

 together with their separations in the following table : 



815-30 (10)22474-44 

 812-77 (6)22545-01 



1784-76 

 1783 



761 



} (2) 23650-23 

 28 J 



1784-68 



(2) 22284-82 



1780-35 (7?i)22310-27 

 1785-64 (<1) 22344 -72 



Before however considering these lines in detail it will be desirable to take here a 

 preliminary discussion which involves a new fact in series relationships, and at the 



