1903.] The Spectra of Neon, Krypton, and Xenon. 



85 





complex than the first in each case, an analogy being thus shown 

 with argon. 



There are about forty lines of weak intensity common to the jar 

 and spark gap spectra of krypton and xenon ; this may possibly be 

 considered as evidence of the existence of another element of higher 

 atomic weight in the same series. 



In the tables of the spectra, columns are given of the measurements 

 which have appeared by Liveing and Dewar and by Kunge in the case 

 of krypton. A very satisfactory agreement is to be observed between 

 the two series of measurements, although those of Liveing and Dewar 

 .are only given to the fourth place. It is interesting that these authors 

 give, in their list of the spectrum lines of the most volatile gases of 

 the atmosphere, about 162 lines which do not appear on the neon 

 photographs, and, therefore, in all probability, do not belong to 

 this gas. 



The most important lines in the visible region of the spectrum are 

 given in the following tables : 



The First Krypton fSpectrum. 



* Probably the green Aurora line. 



VOL. LXXII. 



'! 



