( 478 ) 



fl, D. S.) -(1, H S. S.) — 3583,4 /,, = 27906 3 /,,.= 27909,8 (R. 2) 

 (1,D. S.) — (1,11S. S.) -3661,5 >/, ^27311,3 /„.- 27319,8 (R. 2) 

 (1, D. S.) - (2, Il S.S.) I) ^ 2599,1 /^ = 38474 ;,,.= 3851 1,4 (P. 3) 



(2, D. S.) — (2, 1 S. S ) ^ 2166,2 /^ = 46163,3 

 (2, D. S.) — (1, Il S. S.) 7739,9 ./, ^ 12920,2 

 (2, D. S.) — (1 , II S. S.) = 7704,7 ./, ^ 12979,3 

 (2, D. S ) (2, II S. S.) ) = 1554,2 ;^ -= 64343 

 (2, D. S.) — (2, II S. S.)') 1518,4 /^ -= 65859 



,.— 46190,1 

 ,,= 12924,1 

 J= 12986,6 



(P. 4) 

 (R. 3) 

 (R. 3) 



6,436 //(P). 

 6,567 !' (P.) 



The lines 13442, 10069, 8872, and 8271 form a B. S. The 2üist 

 lines, which are the intensest here too, form a differential vibration : 



(2, B. S.) - (1, B. S.) = 2491,9 h = 40130 ;,, = 4,03 (Mollj. 



The line 5165,35 (R.) is probably a summational vibration of the 

 first line of the P. S. and (1, I S. S.)- It corresponds to 4642,5 for 

 potassium. 



Caesium. Paschen ') gives as first doublet of the i)rincipal series 

 8521,2 and 8943,6. A differential series was not observed ; calculated 

 are the values of the frequencies 10216 and 10589,0 (1,D. S.), 

 14059,1 and 14533,0 (2, D.S.j. 



34892,5 and 36127,7 form the first doublet of the I S.S., 14694,8 

 and 13588,1 the first of the II . S.S. Tiio following combinations liave 

 been observed : 



(1,D.S.) —(1,1 S.S.) =7350,9 

 (1,D.S.) —(1,115.8.) 3412,7 

 (l.D.S.) —(1,11 S.S.) = 3231,0 

 (2, II S.S.) — (1, D.S.) = 2369.8 

 (2, II S.S.) - (l.D.S.) =2552,2 

 (2. D.S.) — (2, II S.S.) ^ 1472 

 (2, D.S.) —(2, II S.S.) ^ 1391,8 



The lines of the I S.S. are accompanied by satellites. In connection 

 with this is that Bergmann's series consists of doublets with constant fre- 



10197 B) ^082,02 (L.) 7280,5 (S.j 

 quency difference. The doublets ^^.>.^o'p':J; 8019,62 (L.j; 7228,8 (S.) ; 



8017,1 (S.) 7227,46 (L.) 



6872,6 (S.) 6630,5 (S.) 6475 (S.) 6359 (S.j , . • ., 



6826,9 (S.)' 6588 (S.) 6434 (S.) 6325 (S.) ^'^'^'' ^'^^"'" ^ ^^^'^^^ '*'^ 



1) (2, 1 S. S.) is liere A = llhl ,'d according to Saunders. (2, II S. S.) is not 

 undoubtedly known. 



2) Here the doublet 7406,19 and 7277,01 of Lehmann have been taken into 

 consideration in the calculation. 



^j F. Paschen, A.nn. d. Pbys. Vol. ?3, 1910, p. 731. 



