32 Clarice and Steiger — Action of Ammonium, Chloride. 



One step further and this becomes 



Ca lt0 AJ 140 X M0 , = l :2:2. 



Treating derivative "B" in the same way, and ignoring 

 chlorine as an unexplained impurity, the analysis gives 



(NH 4 ) 1M Na.Ca„ Al M1 (Si 1 O t Wa0 4 ) 1I , ; 



or, consolidating bases as before, 



R '. M A1 . 8 . X s,8> ="1 : 1 : '1 nearly. 

 The assumption of commingled ortho- and trisilicate molecules 

 conforms to Streng's theory of the constitution of chabazite. 



Thomsonite. 



The compact-fibrous variety from Table Mountain, near 

 Golden, Colorado. Analytical data as follows: 



Fractional water. 



At 100° _ 1-01 



" 180° 1-44 



" 250° 1-05 



" 350° 3'90 



Low redness 5*65 



Over blast . . -08 



100-40 





Analysis. 



Si0 2 



4113 



AI.O,— - 



29-58 



CaO 



11-25 



Na 2 



5-31 



HO 



.. ... 13*13 







13-13 



Before ignition the mineral yielded 0*45 per cent of silica 

 to sodium carbonate solution. After ignition, 0*68 per cent 

 was soluble. The difference is trifling. 



Two samples of the ammonium chloride derivative were 

 prepared. In "A " the heating was only to 300°, in "B" to 

 350 p . Analyses of the leached products gave the following- 

 results : 



A B 



Si0 2 42-41 42-65 



A1 2 8 30-50 3T34 



CaO 10-00 9-23 



Na 2 2-63 2*48 



NH 3 ... 2-45 2-67 



H 2 0.._ 11-96 11-81 



99-95 100-18 



In "A," rSO per cent of soluble silica was found. 



In this case the amount of change is very much less than 

 with the zeolites previously examined. Little lime was 

 removed, and only about half of the soda. Both samples were 

 prepared with six hours of heating in the sealed tube, and it 



