22 The federal SPECIES 



orange-coloured powder, or from the refidue or 

 fulphur -flags, as they are called, with or without 

 further treatment -, or alio in the roatting-huts, 

 which generally appear done over with a red fort 

 of glazing. Some pyrit^e yield more of it,but ftill 

 in the proportion to their fulphur and arfenic. 

 Tho' to fpeak with propriety, it would be a dif- 

 ficult matter to find a pyrites, fo mixed by na- 

 ture, as without large additions to yield much 

 fandarach, and not either moftly a fulphur, or a 

 pure footy arfenic ; for, to compofe a fandarach, 

 the arfenic mud predominate or exceed the ful- 

 phur by about 3 or 4 parts ; and a pyrites of fuch 

 a mixtion is very rare, and what I never myfelf 

 obferved; but rather, that where the pyrites 

 greatly partakes of arfenic, the fulphur is defi- 

 cient ; and where, on the contrary, the fulphur 

 is in a fufficient, not to fay, a large quantity, there 

 the arfenic is not fo. The mifspickel, or white pyrites, 

 is therefore for the mofl part purpofely mixed, either 

 with fulphur- flags orwith fulphur •■ pyrites, as fhall be 

 fhewn hereafter. 3 Tis true, the white-pyrites might 

 be, nay, by fome is really called & fandarach -pyrites,' 

 and 'tis poflible there may be pyrit<e having fuch 

 a proportion of fulphur and arfenic, as to yield 

 fandarach without ufmg any additions. 



But the ufual way of procuring a fandarach is 

 to employ two forts of pyrites, the white and the 

 yellow, or to ufe, as additions, fulphur -flags ; 

 whence it appears, that fandarach is not a conftituent 

 principle of pyrites, but that it confifts of two parts 

 thereof, namely, arfenic and fome fulphur, really, 

 .but difperfedly, exifting in the pyrites^ and run 

 together in the courfe of the procefs for fan- 

 darach. 



Smelters have likewife their ji one-pyrites -, to un- 

 derftand which, it is to be premifed, that ftone at 

 the huts denotes that crude, femi-metallic body, 



• or 



