On Primary Ores of Iron* 



than any other variety ; yet, the ftate of the carbon fo much 

 ufembling foflile plumbago, fo unlike the carbon which the 

 Elba fpecimens afford, and fo widely different from that ob- 

 tained by fufion, together with the fmallnefs and regularity 

 of the ervftals, their luftre and finifli conftitute a wide dif- 

 ference between thefe two ore.-. 



The line red oxyde which fo much refembles cinnabar, and 

 which is found in abundance upon the Elba iron ore, ap- 

 pears to me to be an oxyde of iron deposited by the decom^ 

 poiition of fulphat of iron. Thus far I can fay, that a pow- 

 der exai tlv fimilar was depofited upon the furface of fomc 

 iton-ftones expofed to a high temperature, ift which I had 

 afeertained the prefence of the fulphuric acid. The various 

 (hades of colour which appear upon the Elban ore, exactly 

 referable thofe which may be puffed upon ore, iron, or fteel, 

 bv expofing them under certain degrees of heat to the action 

 yf atmofpherie air. Its fracture is mo ft evidently vitrified, 

 and exactly refembles iron fully combined with oxygen, af- 

 terwards reduced by fution to an opaque and very ponderous 

 glafs. Like the Elban ore, fuch vitrifications, when broken, 

 tUiplay a perfect ftate of cryftallization. 



I have even obtained fpecimens of this ponderous lava pof- 

 felfing a variety and rlchnefs of colouring, equal to many of 

 the Elban fpecimens. 



Though the agency of water will more readily explain the 

 fi.ruc.~tu re, cryftallization and depofition of foflils in general, 

 yet there are circumftances which moft forcibly claim an ex- 

 ception. The Elba ore, in my opinion, is one : I conceive it 

 to be iron oxydated in fufion by the combination of a quan- 

 tity of oxygen, from iS to 24 per cent, inclufive of a fmall 

 portion of earbon, to which, either at the time, or bv a fub- 

 fequent procefs, fomc volatile mixtures have been added. In 

 a more proper place I {hall minutely enter into the nature 

 and aaalyfis of this beautiful ore of iron. I {hall only here 

 exhibit fome ftmple rcfults obtained from it when comparing 



it with ether ores, of iron. 



The 



