CHEMISTRY. 



341 



The Atomic Weight of Praseodymium. 



Mr. 0. J. Stewart has completed the analysis of the various speci- 

 mens of praseodymium chloride, the purification of which has already 

 been briefly described in Year Book No. 12. The purity of the dif- 

 ferent fractions was further investigated. In none of the fractions 

 could neodymium be detected by examination of either the absorption 

 spectrum or the spark spectrum, although it was found possible, by 



Series I. 



