[zumstein] 



THE SPECTRA OF LEAD AND TIN 



61 



In table II are arranged these results, together with the results 

 of Hartly (with the pure metal in an oxy-hydrogen flame), Eder and 

 Valenta (with lead chloride), and de Watteville (with lead nitrate). 



Table II. 



The continued appearance of the lines 4058, 3684 and 3640 indi- 

 cates that these lines are fundamental. 



Table III is made up from Eder and Valenta's spectrum charts, 

 showing the lead lines which occur when lead is contained as an 

 impurity in other metals. 



Table III. 



This again shows the prominence of the lead lines 4058, 3684, 3640, 

 as well as 2833. 



Experiments on the absorption due to Lead vapor in a carbon 

 arc showed that these lines were absorbed in addition to some others. 

 This "was tested in two ways. Spectrograms were taken of (1) a 

 lead spark the light from which traversed a carbon arc containing 

 lead vapor, and (2) the glowing filament of a Nernst lamp, the light 

 from which traversed a carbon arc containing lead vapor. 



The plates used were not sensitive to the line 7229-30, so no test 

 was applied which succeeded in linking this line up with the others. 



The results of these experiments point to the possibility of the 

 lines 7229-30, 4057-97, 3683-60, 3639-71 and 2833-17 being similarly 

 related to the lead spectrum — being in fact, the heads of analogous 

 groups of lines. 



