38 Clarke and Steiger — Action of Ammonium Chloride. 



JPhlogopite. 



From Burgess, Canada. The contents of the sealed tube, 

 after heating, showed little appearance of change. The leach 

 water contained magnesia. Analysis as follows: 



Phlogopite (Schneider). Kesidue (Steiger). 



Si0 2 ._ 39-66 45*03 



TiO„ _ -56 



A1A 17-00 ) . 



Fe 2 3 -27 f 1507 



FeO -20 



BaO -62 



MgO 26-49 24-94 



Na 2 -60 -94 



K 2 Q .. 9-97 8-69 



NH, .... -21 



H 2 ._ 2-99 5-01 



F... 2-24 .„.. 



100-60 99-89 



Less O -94 



99-66 



The residue, on boiling with sodium carbonate, gave 0*40 per 

 cent of soluble silica. From these data it appears that phlogo- 

 pite is somewhat attacked by ammonium chloride, but not 

 strongly. ISTo ammonium derivative is formed. 



. As opportunity offers, this investigation will be carried 

 further, and the reaction will be applied to other mineral 

 species. 



Laboratory U. S. Geological Survey, Oct. 12, 1901. 



