Regulus of Arfenic. 327 



SPECIES IV. 



Mineralized by Sulphur and Arfenic. 

 Arfenicated Antimony. 



8. This is the fame as the plumofe filver 

 ore mentioned among thofe of filver, Species 

 1 1 ; befides the colours there mentioned, it 

 is found red or green, and then contains but 

 a fmall proportion of filver ; its texture fila- 

 mentous, very brittle and fufible. 



9. It is analyfed by folution in aqua regia, 

 both the regulus and arfenic remain in the 

 folution ; the fulphur is feparated by filtra- 

 tion j if the folution be then boiled with 

 twice its weight of ftrong nitrous acid, the 

 regulus of antimony will be precipitated by 

 dephlogiftication, and the arfenic converted 

 into an acid, which will remain in the liquor, 

 and may be procured by evaporation to 

 drynefs. 



10. If filver or copper be fufpe&ed in this 

 ore, it fhould be treated in as Chap. 3. N? 25. 



CHAP. XI. 



Regulus of Arfenic. 



I. Of a bright yellowifh white colour, but 



foon lofes it$ luftire, and grows black by expo- 



Y 4 lure 



