L *53 3 



fmalts, ufed for blueing clothes. Is foluble in ni- 

 tric acid without heat, and in vitriolic acid affifted 

 by heat ; likewife in thq marine and nitro-muriatic 

 acid, which diluted with water, is ufed for fympa- 

 thetic ink. 



a. Grey Cobalt Ore, Arfenicated Cobalt; chiefly 

 compofedof cobalt and arfenic; of a fine-grained, 

 compaQ: texture ; of a fteel-grey colour. Found 

 in Saxony, Bohemia, Norway, in a matrix of red 

 heavy fpar; calcareous quartz, i 



b. White Cobalt Ore, confifts of cobalt and 

 iron, mineralifed by fulphur and arfenic, of a tin- 

 white colour, of a granular and lamellated tex- 

 ture. Found in Norway and Sweden. 



c. Sidpkuret of Cobalt; contains no arfenic of 

 iron ; when heated it emits a fulphureous fmell ; 

 found in cubical cryftals in Upper Hungary, ge*. 

 nerally upon quartz. 



d. Native Oxyde of Cobalt ; Black Oxyde or 

 Calx of Cobalt ; this is the pureft kind of the 

 calciform cobalt ores ; when heated, it emits no 

 fulphureous or arfenical vapours. Found in Thu- 

 ringia, Saxony, Tyrol. Of the oxydes of cobalt 

 there are various fpecies, as Brown earthy Oxyde % 

 Yellow Oxyde, Green Oxyde, Red Oxyde, of Cq~ 

 halt. 



X 



N. ZINC. 



