J S4> Of the Sulphur 



ting it to a fudden brifk fire in a crucible in the 

 wind-furnace) in Mifspickel, along with that earth, 

 which, in a great meafure, is martial, and more- 

 over, very crude. The reafon, doubtlefs, is, that 

 arfenic, as a femi-metallic body, comes nigher than 

 fulpbur to a metallic earth. Such union, however, 

 muft alfo arife from the nature of the fulpbur itfelf, 

 as fhall be hereafter fhewn from compofition -, where 

 I have treated both iron and copper with fulpbur. 



(2.) That fulphur may be found, in a quite crude 

 caft-iron •, for we need not prove, but certainly ad- 

 mit, from the hiftory of the operation of crude- 

 /melting, and alfo frequently in forged iron : but then 

 this muft be owing to an undue degree of fcorifica- 

 tion, and confequently to the mineral fulphur not 

 being properly feparated, as the coarfe grain and 

 brittlenefs of fuch iron plainly fhew : but, if you 

 take a fine tough iron, or, which is better, a fteel ; 

 muft it not then be granted, that, if the fulpbur 

 educed be not the common mineral, but a proper, 

 metallic fulphur, appertaining to the effence of the 

 metal, it fhould be found in all, even the beft fort, 

 as a raecefTary conftituent part : but, from the ground- 

 mixtion and effence of iron, there is properly but 

 one, not a two-fold fort, and fo far no fulphur to 

 be fhewn from any one, 



'Tis certain, we plainly obferve in caft and the 

 like crude iron, fulphur a conftant companion, nor 

 is it a ftranger in black-copper. Now the queftion 

 is, whether it holds firmer and longer in the iron or 

 the copper. 



IF we reflect, that the pyrites mixtion confifts in 

 no fuch compofition as might be fuppofed to arife 

 From the running together, in concotting and fmelt- 



ing 



