193 



chromium, and uranium contents are utilized for the same 

 purpose should induce a demand for the heavy black mine- 

 rals for the manufacture of special steels. 



Mineralogical Laboratory, 

 University of Adelaide. 



PRELIMINARY ANALYTICAL NOTES ON THE MINERALS 

 DESCRIBED IN THE PRECEDING PAPER. 



By E. II. Rennie, M.A., D.Sc, and W. T. Cooke, D.Sc. 



[Read September 4, 1906.] 



At Mr. Mawson's suggestion, we have examined two of 

 the minerals referred to by him in the previous pajoer. As 

 regards the carnotite, we are so far able to confirm Mr. Chap- 

 man's results as to the presence in it of potassium, uranium, 

 and vanadium, and we hope later to furnish quantitative de- 

 tails. As regards the dark-coloured mineral (No. 2 in pre- 

 vious paper), of which the carnotite appears to be a decompo- 

 sition product, we have examined it qualitatively up to a cer- 

 tain point; but the difficulties of analysis are considerable, 

 owing to the complex nature of the mineral. We have, how- 

 ever, ascertained that, in addition to titanic and ferric oxides, 

 which are the chief constituents, there are present uranium, 

 vanadium, cerium, and almost certainly thorium and other 

 rare earths, traces of lime, and, we believe, also chromium and 

 traces of manganese. The quantities of vanadium and chro- 

 mium, however, if present, are very small, and in presence of 

 uranium difficult to detect with certainty. As a result of 

 this, and by reason of other matters which have occupied our 

 time, we send these imperfect preliminary notes in the hope 

 of being able at a future date to offer to the Society a more 

 complete analysis. 



