220 Prof. Renwick on Torrelite. [March, 



thrown in were, after a few hours, dissolved; a precipitate 

 ensued, which, washed, and dried, weighed 8-62 grains. If the 

 representative number of cerium be 92, this, when reduced, will 

 give 6-06 grains of peroxide of cerium. 



(3.) The liquor whence the cerium had been precipitated (2), 

 being tested by the oxalate and benzoate of ammonia, showed 

 the presence of lime and protoxide of iron. 



The more important results of the analysis B. being thus con- 

 firmed it was not considered necessary to extend the process 

 farther. The results may be, it is believed, depended upon, 

 except so far as the equivalent numbers of ferrocyanic acid and 

 cerium enter into the calculations of (B. 10) and (C. 2), and the 

 doubt whether a small proportion of some other metal may not 

 have been thrown down in (B. 10). This analysis shows the 

 following to be the constitution of the substance : 



Grains. 



Silex, B. (4).. 16-30 



Peroxide of cerium, B. (8) 6*16 



Protoxide of iron, B. (10) 10-50 



Alumine, B. (1 1) 1-84 



Lime, B. (12) 12-04 



Water, C.(l) 1-75 



Loss 1-41 



50-00 



As this mineral neither agrees in external characters nor 

 chemical constitution with any other compound of cerium, that 

 has been hitherto described, I have little hesitation in announc- 

 ing it as a new ore of that metal. It appears to possess the 

 nearest analogy in its composition with the AUanite. This last, 

 by the analysis of Thompson, quoted in Macneven's edition of 

 Brande's Chemistry, has in 50 parts, 



Silex 15-80 



Oxide of cerium 15-13 



Alumine 1-83 



Protoxide of iron 1 1-34 



Lime 4-11 



Water 1-79 



50-00 



If my surmise in this respect be true, I should propose to name 

 it the Torrelite, in honour of my friend Dr. John Torrey, to whom 

 mineralogical science is under many important obligations, and 

 to whom this tribute is fairly due, as it is to his nice tact in the 

 management of the blowpipe, that the discovery of cerium in 

 the substance is to be attributed. 



