Seines System in the Spectrum of Gold. 29 1 



belong to a normal P. We require si doublet with separation 

 3815, such that the sum -of the larger W.N. and 29469 shall 

 show a mantissa within possible reach of s(l). There are 

 only two observed in the region involved, viz. : 



(2^)17879-43 (3)17573-91 



381692 381866 



(6)21696-35 (6)21392-57 



both spark lines not seen in the arc. They are possibly, 

 therefore, both P doublets modified in some way, as is 

 indicated also bv the enlarged separations. Since 21690*35 + 

 29469*85 = 51166*20 = N/{l*464071p, the P(oo) is near a 

 possible *(1). Both the limit 51166 and the line 21696 are 

 near the values given by the r-t- c linkage in the P' series- 

 The lines given in the following table seem to give at least 

 one set of P series. The pair for m — 2 are both seen in the 

 arc, but are enhanced in the spark. The formula for P r 

 found from the first and second is 



m = 51166-2Q~N/J m+ '978446- '° 49298 ) 2 . 

 / I m J 



This gives for m = 3, 44179*44 with 0-C=-*l. Form=4 > 

 ?i = 46719'15 the nearest observed line being (1^)46703*65. 



For the first two orders any P lines would lie in the un- 

 observed ultra violet. For m==3 there are seen two which 

 serve for P(3) lines, in which it may be noticed that the 

 means give a larger limit than that assumed, but one in 

 accordance with the enlarged separations observed. A dis- 

 placement S, in S(oo) increases v by 2*17 to 3817*73 and 

 8 (x) by 10*76. Hence P(oo) should be 51176-96, which, 

 duly appears for P 3 (3), Pg(3) : — 



P. 





P. 



r (2^)17879-43 

 J I (6)21696-35 





Outside observed region. 



f (8)37844-09 

 -\ (6)38595-88 









" " 



, f(4») 43892- 19 

 3 I (An) 4418 1-90 



5117 5-60 +V7p (3)58459-02 (-81,123) 



51169'!' 



y+l-7p (4) 58156-44+3-3^ (-200, 57) 



The S Series. The 8(2) set are quite definitely 13309*98 

 (corrected from Lehmann's 13312*9 + 13) and 17125*54, both 

 from their analogous position with the S (2) lines in Ou,Ag 



