in the Pyrites. ,137 



I cannot omit fuggefting here fomething very 

 remarkable; whether to call it a new difcovery in 

 mineralogy, particularly in the doctrine of fulpbur , 

 I know no: 5 wnich, in fhorr, is this, that in the 

 crude fuklu7\ there is an actual iron- earth con- 

 tained, whkfc nor only is read iiy acted upon by 

 thr magnet, but is alio met a li fed. 



For if yon take the fulpbur- flags, and burn them 

 in a ciucibl-j or pot, you procure a grey i en, afhy 

 earth, which the magnet attracts, and which, by 

 proper additions^ may be reduced to un iron-regu- 

 lus j and cfak not only when the fulpbur is treated 

 in an iron rl Dg t, i v- ufing which might give fuf- 

 picion of eft i n iak of the fulpbur having cor- 

 n d d and del tome of the iron of the por, 



but aito in earth. 11 retorts. 



We have here befides two remarks more to 

 make : f 1 .) That the above is a certain truth, which 

 may often clear up an experiment, that may hap- 

 pen to be m.-.ue with fulpbur flags, and contribute 

 to attain the knowledge of a natural body ; whether 

 the iron it holds, happen to be derived to it in 

 an incidental manner from the vefTeis, in thr coorfe 

 of the purification, or in the firft defvJpbur alien 

 fublime alorg therewith from the ground- iron- 

 earth of the pyrites, 



(2.) The more clearly to difclofe my thoughts 

 on this head, I am in general to enquire, whether 

 it would be any abfurdity to fuppofe the render 

 iron-earth, as it is in the pyrites, to be at the fame 

 time vola till fed in the de fulpbur ation of the pyrites ? 

 The copper- earth is, however, fitted for tin- vo- 

 latihfation, as the copper-panicles in ibefjriUJ ad- 

 here 



