Art. XVI.— Oh the Spectra of the Alkalies. 

 By L. Rum mel. 



(Communicated by R. L. J. Ellery, C.M.G., F.R.S.) 

 [Read 12th November, 1896]. 



In the paper I venture to lay before the Royal Society of 

 Victoria, I have attempted to detei'mine the values of the wave 

 lengths of the spectrum lines of the alkalies, as formed into 

 series by Kaiser and Runge, by means of a new formula. To 



y 



this formula I have given the shape X n =x + —^ , A meaning 



the wave length, ;/ a whole number, commencing with 2, and 

 x, y, z 3 constants. It requires three equations to determine 

 these constants. Supposing three members of a series, viz., 

 a, b, c, are known to form the series 3, 4, 5, then we get the 

 three equations : 



b= x +y 



lb - z 



which give the solution : 



„_ Q ll2(d-c) 



16(a-b)-7(a-c) 



(«-J)(9-g)(16- g ) 



7 



y 



x = a- •* 



9-2 



If the numerals are respectively 4, 5, 6, the values are : 

 180(b-c) 

 20(<z - b) - 9(« - c) 

 _ ( a -b)(l6-z)(25-z ) 

 J 9 



