39 



driven off by boiling with dilute hydrochloric acid and collected in 

 a potash apparatus. The fluorine was expelled as silico-fluoride, 

 was collected in a soda solution and then precipitated as 

 fluoride of calcium. The precipitate obtained by ammonia 

 from the mineral solution was dissolved in hydrochloric acid, 

 and the v«olution was saturated with potassium sulphate, by 

 which the cerium eartlis were thrown down. The slight amount 

 of precipitate obtained by ammonia from the filtrate was attributed 

 to yttria. The cerium oxide was separated from the lanthanum and 

 didymium oxides by leading chlorine for some time into potash 

 solution in which the oxides were suspended. The undissolved 

 residue was taken to be oxide of cerium. The values thus 

 found are given below under 1. Those obtained by Dam our 

 and De ville from the mineral from Muso are given under II. 



I. 



П. 









Molecular 





Molecular 









ratios. 





ratios. 



CO, . 





. 26,54 



. . . 0,6032—2 



■ 23,48 . . 



. . 0,5337—3 



Ce,0,. 





. 28,14 





44,17 





La.^0.^ 

 Di^O., 



1- 



. 22,88 



> . . 0,3221 — 1 



8,05 > 

 9,98 . 



. . 0,3702- 2 



Y,0, . 





1,23 









CaO . 





. 17,13 





10,11 . . 



. . 0,1808—1 



Na^O . 





. 0,19 



. . 0,3103—1 







K^O . 





. 0,12 , 









F . . . 



"- 



5,82 

 102,05 



. . 0,3063—1 



5,55 . . 



.■ . 0,2921 — 2 





101,34 





— . . 





2,45 





2,34 





99,60 



99,00. 



For the mineral from Narsarsuk the chemical formula thus 



becomes 



CeFCaC^O^, 



in which Ce indicates all metals of the rare earths contained in 

 the mineral, and Ca stands for calcium together with the small 



