TKANSACTIONS OF SECTION B. 



567 



Notice, also, how orderly the metals discovered by spectrum analysis fit in their 

 places — gallium, indium, and thallium. 



The symmetry of nearly fill this series proclaims at once that we are working in 



t' .Bvert. \ 



IPctra Tuaa^ ett 'c 



JDtaTnapnettc. ^ 



Lt'+^ 



+ JVit 



^J\<rn' 



SS^^^^BS 



_ W' — / 



± Ga 



+ 'vZ« 



1 170 



\ . 1 1 



1 < 1 I 



Fu;. 1. 



the right direction. We can also leavn much from the anomalies here visible. 

 Look at the places marked with a circle ; didymium, samarium, holmium, erbium, 



