[ainslie-fuller] 



ULTRA-VIOLET OF CERTAIN METALS 



73 



Thallium. 



The thallium vacuum arc spectrum was obtained by putting 

 thallium in iron terminals. The current used was about 6 amperes 

 which gave a continuous and intense arc. There is considerable 

 variation in these results from those of Saunders. This may be due 

 to the fact that Saunders used standard aluminium and zinc lines, 

 while in this work the gas lines measured by Lyman were used as 

 standards. 



