Cobalt. 335 



pulverized ore with i of pounded glafs, and 

 i of calcined borax, melting the whole in a 

 crucible lined with charcoal. 



CHAP. XIIL 



Cobalt. 



1 . Cobalt, or regulus of cobalt, as it is 

 called by fome, is of a bluifh grey colour, 

 very hard, brittle, arid fteel grained ; its fpe- 

 cific gravity is about 7,700; its fufibility is 

 nearly as that of copper ; it is difficultly cal- 

 cined, and its calx is of a blue, fo deep as to 

 appear almoft black; and this calx melted 

 with borax, or potafh and white filiceous 

 fand, gives a blue glafs : this calx is not vo- 

 latil ; the regulus is eafily foluble in fpirit of 

 nitre or aqua regia, and the colour of the fo- 

 lution is red, but difficultly in the vitriolic 

 and fcare at all in the marine acid j the calx 

 is more eafily diflblved by thefe acids ; it 

 yields even to the acetous. 



SPECIES I. 



Native. 



2. This has not as yet been found ; that 

 which pafles for fuch is mineralized by 

 arfenic. 



SPECIES 



