348 



Hartley and Ramage — Banded Flame-Spectra of Metals. 



The Flame-Spectrum of Lanthanum. 



The oxide was heated in the oxyhydrogen flame. Bands degraded towards 

 the red. 



There appears to have been lanthanum in the preparation of samarium 

 examined by Thal^n, or samarium in this specimen of lanthanum nitrate. There 

 was also probably lanthanum in Thaldn's specimen of the didymium salt, from 

 which the spark-spectrum was taken. 



The flame-spectrum was taken from a specimen of lanthanum ammonium 

 nitrate, kindly given by Professor C. M. Thompson, D.Sc. of the University College 

 of South Wales, Cardiff. It had been prepared by the method of Auer v. Welsbach, 

 from monazite. 



It is to be remarked that Exner & Haschek give lines in the spark-spectrum 

 of lanthanum, having wave-lengths which approximate to those of the edges of 

 several bands in the third group of the flame-spectrum, viz. 4455*99, 4436"02, 

 4433-15, 4423-37, 4419-30, 4378-24. 



