436 Foote and Bradley — Chemical Composition of Analcite. 



and after igniting and weighing was fused with potassium 

 bisulphate in order to make a volumetric determination of iron 

 possible. Calcium was absent in all cases, and not more than 

 the merest trace of magnesium was found. Alkalies were 

 determined by a Smith fusion, and water by ignition. The 

 analyses and the ratios calculated from them are given below 

 (Table III). 



Table III. — New Analyses of Analcite. 



1. Two Islands, N. S. 



I II Average Eatio 



SiO„ 55-90 55-90 55'90 4'46 



AL0 3 22-38 22-41 22-40) •__ 



Fe 2 3 _. -11 -12 -ll| 106 



K 2 -06 .... -03 



Na 2 12-85 12-96 12-91 j" 



H 2 G .__ 8-38 8-33 8-35 2'24 



99-68 99-72 99'70 



2. Cyclopean Islands. 



I II Average Eatio 



Si0 2 54-39 54-42 54-41 4'16 



A1„0 3 23-73 23-52 23'62 ) , h 



Fe' 2 3 '12 -13 -12 \ Vm 



K 2 0-- '12 -11 -12) 



Na 2 13-30 13-42 13-36 f 



HO _.. 8-24 8-25 8'24 2-12 





99-90 



99-85 



99-87 







3. Kerguelen Islands. 









I 



II 



Average 



Eatio 



Si0 2 



54-49 



54-86 



54-68 



4-18 



A1 2 3 



23-23 



23-43 



23-33 | 

 •14 \ 



1-05 



Fe 2 3 



•15 



•14 



K 2 





•03 



•02 ) 



1-00 



Na 2 



13-37 



13-57 



1347 j 



HO 



8-46 



8-47 



8-46 



2*17 



2 







99-70 



100-50 



100-10 







4. Victoi 



•ia, Australia. 









I 



II 



Average 



Eatio 



Si0 2 



55-09 



55*02 



55-06 



4-29 



A1 2 U 3 



22-84 



22-87 



22-85 | 

 •15 f 



1-05 



Fe 2 3 



•15 



•15 



MgO 



•25 



•10 



•17 I 



1-00 



Na 2 



13-20 



13-16 



13-18 \ 



H,0 



8-32 



8-44 



8-38 



2-19 



99-85 



74 



99-79 



