360 
DR. W. M. HICKS; A CRITICAL STUDY OF SPECTRAL SERIES. 
m = I. In S(l) cases of the displacement associated with the linked lines have 
been given above. They also exist in connection with the S lines themselves. Near 
82 ( 1 ) are 42448’25 and 42473‘49, both of intensity 1 ; the first I4‘42 above and the 
second 10'82 below 82 ( 1 ), or a difference of 25'24 = 2xl2’62. Again (3) 42401‘45 
is 14'38 above 83 ( 1 ). Now 3|-^ = 14^^ displacement on 8 (co ) produces a separation 
of I4’42, and of 2 |-(^ = 10(5i one of 10'30. If, therefore, the observation errors are 
very small the lines in question are respectively ( —14^i) 82 ( 1 ), (lO^i) 82 ( 1 ), and 
( —14(5i) 83 ( 1 ). There is no corresponding (—14 ^ 1 ) 81 (l), but (l) 42623‘93 is 
( — 18 ^ 1 ) 81 ( 1 ) with dX = '00. 
m = 2. In 8 ( 2 ) we find direct displacements on the 8 ( 2 ) lines with a whole set 
of linked lines. They are indicated in the following table :— 
(9) 26806-14 
(4) 26562-08 
182-07 (3)26744-15 
75-60 
(1) 26833-37 
- e (7) 25841 
- -13 
- e (.3) 26022 
-e(3) 26098 
-2e(5) 25121 
- -09 
e (2) 27464 --12 
-e + 24-61 (.3) 26123 
-3e(l) 24399 
•30 
-M (2) 26.305 --12 
-w(3) 26123 
•06 
-e-u{l) 25582 
-e + -y(.3) 26285 
•00 
- 3e + v{3) 24845 
•00 
The line 26562 has been already adduced. It is ( — 2 (!) 8 i( 2 ) with dX — —'02. 
The lines 26022, 26098 under ( 6)83 and ( 0)83 differ by 75’57 or a normal 1 ^ 2 , and 
refer back to lines which would give the true triplet separations with the first 
line 26542. 
m = 3. From 81 (3) the two lines (l) 40258‘62 and (4) 40273'21 are displaced 
successively by 14‘57 and 14‘59, the same separation as in the case of m = 1 . They 
are { —14(^,) 81 (3) and ( —28^i) 81 (3), with 0 —G given by dX = '00 in both cases. 
The first has a modified e link —722'61 and the second another of 718'46 to observed 
lines (4) 39536'01(6) 40991'67. 
The D and F Series. 
It will be found that the rare gases show a large preponderance of sets of hues 
which have all the characteristics of belonging to satellites of D series, or to parallel 
multiplet F series. In other words where, as in other elements, the d sequences 
show two displacements from the main sequence when triplets are in question, the 
rare gases show a large number of such displacements, both in the d and the f 
sequences, many of these being due to large multiples of A 2 . No attempt has been 
made to determine the whole system of these satellite sets, a problem belonging to 
an intensive study of individual elements, but a sufficient number have been adduced 
to prove their existence and to exhibit some of their characteristics. 
