I 3 2 



C II A P. IX. 



Of the Sulphur in the Pyrites. 



AFTER having treated of the metallic, as 

 well the martial as venereal, and of the un- 

 metailic earth, and confequently of thole parts of 

 the pyrites which are fixed, we now proceed to 

 confider the oihers ; and firft, the fulpbur, which 

 is a body peculiar to the mineral kingdom alone, 

 as no one fort of ore is to be found without it 5 

 fome partake of it in a larger, others in a fmaller 

 proportion > though it is fcarce, if at all, to be 

 found mixed with tin, bifmuth, and cobald : it 

 mixes indifferently well with arfenic, alfo gold, 

 more readily with filver, and ftill more fo with 

 lead, iron, and copper, but, above all, with quick- 

 filver, and regulus. As to tin, I never yet met 

 with any tin-ore, that (hewed the lead trace of Jul- 

 phur, but rather a pure peiJon-meal 9 or arfenic ; 

 though this tin ore be not eafily feparable from wot- 

 fram 9 a kind of mock- tin, or an irony tin mineral, 

 which priuft therefore have fame futpbur. A genu- 

 ine fmalt-cobald, in this refpecl, greatly refembles 

 tin •, and from bifmuth- ore, as fuch, to extract any 

 fulpbur, would be more than a little extraordinary. 

 Arfenic, when contained in the mineral called poi- 

 fon-pyrites 9 or mijjpickei, may admit of fome ful* 

 phw, but fmalt-cobald with none 9 a circumftance 

 worth remarking. 



iy 



Further, though regulus of antimony be fo near- 

 allied to bifmuth, as appears by a variety of ex- 

 periments, 



