ALUMINA. C 289 



Silica . . . 36-154 



Alumina . . . 2 8 -669 



Deutoxide of manganese IQ-lGO 



Peroxide of iron . . 2-290 



Lime . . . 0-271 



Fluoric acid . . 1-470 



Water 10-? 80 



98-794 



It appears from Professor Stromeyer's experi- 

 ments on this mineral, that it is usually mixed 

 with particles of fluor spar. To the presence of 

 this spar in minute quantities, I have no doubt 

 that the lime and the fluoric acid found by Stro- 

 meyer owe their origin. It is true that the lime 

 and fluoric acid were not found in the same pro- 

 portions as they exist in fluor spar ; for I shall 

 show, in a subsequent chapter of this work, that 

 fluate of lime is a compound of 



Fluoric acid 1-25 

 Lime . 3-5 



4-75 



But the accurate analysis of this mineral is at- 

 tended with so much difficulty, that much great- 

 er errors than those here suspected have been 

 committed by the most expert analysts. 



The manganese was obtained, and weighed by 

 Stromeyer, in the state of deutoxide ; but it 

 must have existed in the mineral, in the state of 



VOL, I. T 



