THE GROWTH OF OUR KNOWLEDGE OF HELIUM. 285 



investigated ; those which give the D. line beino- marked 

 with an asterisk : — 



*.Eschynite. 



Almandine. 



Anglesite. 



Anhydrite. 



Augite. 



Barytes. 

 *Broggerite. 



Bronzite. 



Calco-uranite. 



Cassiterite. 



Celestine. 



Chalk. 



Charnockite. 



Chromite. 

 *Cleveite. 



Columbke. 



Crocidolite. 



Cupro-uranite. 

 *Eliasite. 



Enstatite. 

 *Euxenite. 

 *Fergusonite. 



Franklinite. 



Gadolinite. 



Gahnite. 



Geikielite. 



Gneiss. 



Granite. 



Graphite. 

 *Gummite. 



Haematite. 

 *Hielmite. 



Hornblende. 



Hypersthene. 



Ilmenite. 



Iridosmine. 

 Kielhanite. 



Kyanite. 



Ludvvigite. 



Magnesium. 



Magnetite. 



Manganese Nodule. 



Minium. 

 *Monazite. 



Obsidian. 



Olivine. 



Olivine-Enstatite. 

 *Orangeite. 



Orthite. 



Pitchblende. 



Plumbic Ochre. 

 *Polycrase. 

 *Pyrochlore. 



Quartz. 



Red Clay. 



Rhodonite. 

 *Samarskite. 



Schurlomite. 



Sphene. 



Staurolite. 



Thorite. 

 *Thoro-gummite. 

 *Uraninite. 



Uranocircite. 



Uranophase. 



Wulfenite. 



Wolfram. 



Xenotine. 

 *Yttro-Gummite. 



J. Norman Lockyer. 



