338 Elements of Mineralogy. 



nitre and Glauber's fait, if the vitriolic acid 

 be the mineralizer, or arfenicated foda, if the 

 arfenical acid exifts in the compound. 



SPECIES IV. 

 Mineralized by Arfenic, with fear ce any Iron. 



Grey Cobalt Ore. Stahl derbon Kobalt, Glanty 

 Cobalt. 



7. Solid, heavy, compact, fometimes of a 

 dull, and fometimes of a bright appearance, 

 frequently cryftalized in a teflelar, fometimes 

 In a dendritical form, and generally fo hard 

 as to give fire with Heel. 



8. It is analyfed by folution in aqua regia, 

 or nitrous acid and evaporation to drynefs ; 

 the reiiduum treated with the acetous acid 

 will yield to it the cobaltic part ; the arfenic 

 ihould at firft be precipitated by the addition 

 pf water. 



9. Or elfe this ore may firft be roafted to 

 expell the arfenic, and then treated with ni- 

 trous acid, the cobalt will be diflblved with 

 very little of the iron, then by boiling the 

 folution moft of the iron will be precipitated, 

 and by adding a fixed alkali, the remainder 

 of the iron will firft be precipitated yellowiih, 

 and afterwards the cobalt reddifh. Mem. EerL 



