408 Dr. Thomas Thomson and Dr. SteeVs [June 



The 15 grs. of white matter were therefore composed of 



Yttria 13*6 



Peroxide of cerium . 1*4 

 Manganese . . . trace 



15-0 

 F. The oxalic solution from (C.) was precipitated by ammo- 

 nia, and the precipitate washed to get rid of the oxalic acid. 

 It was then dissolved in muriatic acid. To separate the glu- 

 cina from the iron, caustic potash, and then carbonate of am- 

 monia were tried ; but neither of these methods was found to 

 answer. The separation was therefore accomplished by the 

 same process as in the former analysis. There were obtained 

 Peroxide of iron . . . 4*53 = 4*077 protoxide 



Glucina 3-47 



This analysis gives the composition of gadolinite as 

 follows : — 



Silica 7-300 - 24-33 



Yttria 13-600 - 45-33 



Protoxide of cerium . . 1*300 - 4-33 



Glucina 3-470 - 11*60 



Protoxide of iron . i i 4-077 - 13-59 



Platinum trace - trace 



Manganese trace - trace 



Moisture 0*296 - 0*98 



30*043 100*17 



This analysis gives us the constituents of gadolinite as 

 follows : — 



12*16 atoms silica 



8*06 ,, yttria 



0*88 ,, protoxide of cerium 



3*91 ,, glucina 



3* ,, protoxide of iron. 



Were we to suppose the protoxide of iron to be an acci- 

 dental ingredient, we might consider gadolinite as com- 

 posed of 2 atoms silicate of yttria, 



1 atom silicate of glucina and cerium, 

 or we might consider it as composed of 



1 atom silicate of cerium, 



4 atoms silicate of glucina, 



8 ,, silicate of yttria. 



