New Mineral. 301 



pitate. Sulphuretted hydrogen separated a minute portion of 

 sulphuret of iron, which, dissolved in nitric acid, and precipi- 

 tated by ammonia, gave .008 peroxide of iron. 



m. The liquid precipitated by sulphuretted hydrogen was 

 evaporated to dryness in a weighed platinum crucible, the sal 

 ammoniac driven off, and the tartaric acid destroyed by burning, 

 after which there remained .073 of a light yellowish earth, 

 which was found to contain neither yttria nor titanic acid, and 

 which, in all respects, comported itself like thorina, tinged with 

 peroxide of manganese. I ought on this occasion to mention, 

 that the presence of thorina in the solution after precipitation 

 by sulphate of potash, is an error in the process, arising from 

 the circumstance, that the earth was not fully precipitated by 

 the sulphate of potash ; an operation, however, which is very 

 easy when the solution employed is not too concentrated. I 

 shall return to this subject in describing its double salt. 



The whole results of the analysis give for the composition of 

 thorite : — 



5. 100. 



Since, in this analysis, chlorine is developed during the solu- 

 tion of the stone, it is plain that both the iron and the manga- 

 nese exist in it in the state of peroxide. From the investiga- 

 tion into the saturating power of thorina, hereafter detailed, 

 it follows, that the oxygen, in all the bases together, is equal to 



X2 



