62 



THE ROYAL SOCIETY OF CANADA 



Regularities in The Spectrum of Tin. 



As tin falls in the same group with lead in the periodic table we 

 should expect similarities in their spectra, as has been often recorded. 

 Kayser and Runge^ found a group of thirteen lines which repeated 

 itself with the same frequency difference, three times through the 

 spectrum. The frequency differences were 5187-03 and 1736-73. 



In the work on lead it was pointed out that a group of three lines 

 existed which repeated itself five times with constant frequency 

 difference. This was immediately found for tin when looked for. 

 The five groups are: 



The marked lines are absorbed in the tin-carbon arc. 

 The line 2061-00 has not yet been observed. 

 The frequency difference between : . 



I and II is 5186-2 



II and III is 1736-1. 



III and IV is 1692-4. 



IV and Vis 288-1. 



From this we see that I, II and III are included under Kayser 

 and Runge's first three groups. This was in agreement with the work 

 on lead which suggests a series of quintets. The flame spectrum of 

 tin in the Meeker burner was photographed to see if the heads of the 

 five series 380M6, 3175-12, 3009-24, 2863-41, 2840-06 appeared. 

 However, in no case was a line spectrum obtained; the band spectrum 

 always appeared. 



Only two experimenters have observed a line spectrum from the 

 flame fed by a tin salt. 



De Watteville^ used the protochloride of tin, Eder and Valenta 

 observed a few lines along with the band spectrum. The work of 

 these two is here given. 



^ Loc. cit. 

 ^ loc.cit. 



