W. T. Schaller — Composition of Hulsite and Paigeite. 547 



Tlie other two samples were prepared from the specimens at 

 hand, sample No. 2, consisting of finely-ground material, for 

 which reason the value for FeO may be somewhat low. Sam- 

 ple No. 3 consisted of coarser material, otherwise very similar 

 in character to that of No. 2. 



Analyses of the second sample yielded the following results : 



Analysis of sample No. 2, paigeite. 



FeO 40-82 40-82 



MgOJ 2-02 2-01 2-10 2-04 



CaO .._ 4-28 4-31 3*81 4*13 



Fe 2 3 18-19 19-34 18-48 18*67 



Total iron as Fe 2 3 ._ 63*54 64-69 63*83 .... 



Sn0 2 3-15 3-14 3-26 3*18 



B 2 3 . 9-10 9-10 



Insoluble 16-18 15'74 16*38 16-10 



Si0 2 , A1 2 3 ,H 2 by difference 5-96 



100-00 



Considering all the lime as resulting from the solution of the 

 gangue, the ratios deduced from the above analyses are : 

 Eatios of analyses of sample No. 2, paigeite. 



FeO __ -567) 



MgO _ -051 \ ^ y4 



Fe 2 3 *117 5-6 



Sn0 2 _. -021 1-0 



BO -130 6*2 



Hid 



From these ratios the formula, incomplete in regard to the 

 water content, is 29*4K0.5*6Fe 2 3 .lSn0 2 .6-2.B 2 3 . + ? H 2 G. 



•Analyses of the third sample yielded the following results. 

 The evidence having indicated that the gangue was consider- 

 ably dissolved by the HC1, direct determinations of the silica 

 and alumina were made. 



Analysis of sample No. 3, paigeite. 



12 3 Average 



FeO 34-68 34-86 35'52 35'02 



MgO 2-25 1-89 2-22 2'12 



CaO 8-97 8-56 8'84 8*79 



Fe 2 3 1469 14*84 15-18 14-90 



Total iron as Fe 2 3 . 53-22 53*57 54*62 .... 



Sn0 2 ._ 2*77 2-86 2*76* 2-80 



B 2 3 6-71 7-16 6-94 



Insoluble 1862 1881 18*29 18*57 



Si0 2 3*28 2-78 3*25 3*10 



A1 2 3 2*51 2*41 2-09 2*34 



H 2 0, etc by difference 5*42 



100*00 



* A fourth determination of Sn0 2 gave 2*97 per cent. 



