On the Spectra of the Alkalies. 263 



The head-lines of 5 and 6 differ greatly from the experimental 

 values. The equations 



7822 



5. 2865+ /"^ ■X* 



rr - 2 - 3b2 



6. 2865+ , 78 ~ =A" 



n -2-0/1 



would put them and the other lines into perfect accord, excepting 



the two pairs < 0(l/ , and-; „,„- which would be reduced to 

 r | 344b I 321 < , 



\ ^J-'^Q auc ^ ' °->10 Perhaps an error has been committed. 



Rubidium, Three of the lines, viz., 6160, 6071 and 5654 are 

 not included in my equations. The first of the three lines looks 

 suspiciously like the Sodium line 6161, and the other two lines 

 may be due to Iron or Titanium. The four equations are : 



21171 



1. 4815 +- > - ii 'j =A" 



n — i't oo 



.„_ Q - , 20649 ,„ 



2. 47o9-5 + — — - — ^=X" 



?i- - I -735 



8452 



3. 2981 +— 2l±L—=\n 



tr - 2T5o 



8428 



Caesium. Only one line, viz., 5579 has not been included in 

 the four equations which are : 



rr — 2 - b4 



2. 4965+ 2 231 f* =*" 



n - 2 - 84 



9564 



3. 3199+ m l\ =\" 



tr - 2 T 4 



949 2 



4. 3199+ , =A" 



n - 2 



In conclusion I may say, that the above formulas do not 

 pretend to be final, but to draw the attention of physicists to a 

 novel way of ascertaining the members of the series of other 

 spectra and to determine, which lines are essential and which are 

 due to foreign bodies. 



