224 A SYSTEM OF 



on account that it is found in the Hungarian gold 

 mines : Yet ftill we know no more of the confti- 

 tuent parts of this femi-metal than the others, 

 notwithstanding all that has been wrote en the 

 fubject. Some fay that its earth is not vitriflable, 

 becaufe it is volatile, which is perfectly contrary 

 to experience : And if volatility is the characteris- 

 tic of a mercurial earth, the pipe clay from Co- 

 logne ought to be of the fame nature. Perhaps it 

 is better to fay that the calx of antimony is vola- 

 tile, and is incapable of being reduced into a me- 

 tallic ftate with phlogifton alone, but may be melt- 

 ed into glafs ; and fuch is its nature, though we 

 do not know the reafon of it. 



SECT. CCXXXVIIL 



5. Arfenic, Arfenicum. This is 



#. In its metallic form nearly of the fame 

 colour as lead, but brittle, and changes 

 looner its mining colour in the air, firft to 

 yellow, and afterwards to black. 

 h. It appears laminated in its fractures, or 

 v here broken. 



c. Is very volatile in the fire, burns with a 

 frnall flame, and gives a very diiagreeable 

 fmell, like garlick. 



d. It is, by reafen of its volatility, very diffi- 

 cult to be reduced, unlefs it is mixed with 

 other metals : However, a regulus may 

 be got from the white arfenic, if it is 

 quickly melted with equal parts of pot- 

 afhes and foap ; but this regulus contains 

 generally fome cobalt, mo'ft of the white 

 arfenic being produced from the cobalt 

 ores during their calcination. The white 

 arfenic, mixed with a phlogifton, fublimes 



like- 



