199 



was dissolved in a very small quantity of hydrochloric acid 

 and cerium precipitated with oxalic acid. In the filtrate 

 thus obtained manganese was precipitated with sodium car- 

 bonate. In the filtrate from the precipitate by ammonium 

 sulphide, calcium Avas determined in the usual manner.» 



«Sodium was determined in a special portion. Water 

 was estimated directly, as the mineral oxidizes on ignition.» 



I. 



per cent 



TiO, . 

 Ce, O3 

 FeO . 

 MnO . 

 Ca . 

 Na^O 

 H,0 . 



5106 



0-68 



1-47 



2-79 



12-90 



19-48 



10-71 



1-36 



100-45 



85 

 

 

 3 



18 



34 



17 



7 



equiv. 



10 \ 



91 



II. 



per cent 



87 

 15 

 79 

 24 

 56 



57-7 



24-8 



51-46 



0-69 



1-41 



2-80 



12-91 



19-50 



9-96 



1-27 



100-00 



III. 



per cent 



49-97 



0-67 



1-36 



2-70 



12-50 



18-90 



12-36 



1-54 



100-00 



I. is schizolite, according to Chr. Christensen's analysis. 



II. are the percentages calculated from the formula: 



1 5 [Si, Гг) O2 • 1 ( Ca, Мп, Fe, Ce) О Л {Na, , Я^ ) О. 



III. are the percentages calculated from the formula: 

 3 {Si, Ti)0,'2{ Ca, Mn, Fe, Ce) О -{Na,, H,) О. 



For simplification cerium is counted as bivalent. As will 

 be seen from the table the result obtained for the schizolite is 

 the formula : 



1 b[Si, Ti) 0, . 10 (Ca, Mn, Fe, Ce) О • 4 {Na, H), О 

 corresponding to 



\bSiO,- \QBO-AB,0, 



CeO. 



