'6 ART. 15. M. OGAWA : PRELIMINARY 



The lines were not remarkably strong, but three lines could be 

 observed in the green-blue part of the spectrum. There were no 

 manganese lines. Of the three lines, the strongest was the one 

 having the wave-length 4882, believed to be correct within 10 

 units. The other two lines could also be measured, but owing 

 to their feebleness, the statement of their wave-length is here 

 reserved. 



Examination of Reinite. 



The finely pow^dered mineral was fused with a mixture of 

 sodium carbonate and potassium nitrate, the fused mass treated 

 with water, ferric oxide filtered off, and the filtrate was saturated 

 with carbonic acid gas. A brown precipitate, containing a little 

 iron and silica, but, otherwise, apparently the same as that ob- 

 tained, under like conditions, from the oxide extracted from 

 thorianite, was produced. This was dissolved in dilute hydro- 

 chloric acid and examined spectroscopically. The spectrum was 

 exactly the same as before, thougli other lines were observed in 

 addition. 



Another portion of the powdered mineral was digested with 

 hot nitro-hydrochloric acid, until its brown colour was completely 

 changed into yellow, the solution evaporated to dryness, and the 

 residue extracted with water acidified with hydrochloric acid. 

 The solution, separated from insoluble tungstic acid, was saturated 

 with hydrogen sulphide, the black precipitate thereby formed 

 was filtered off, and the filtrate, after evaporation and oxidation, 

 was treated with ammonia. The hydroxides of the iron group 

 thus precipitated were redissolved in dilute hydrochloric acid, 

 boiled with sodium thiosulphate in order to remove iron, and 



