372 On Metallic Minerals. 



greatly improved ; and also that the ore on the top of the 

 bed, particularly those fragments which have been long 

 lying detached and exposed to the weather, have undergone 

 a similar improvement in their quality. This might be 

 expected to take place a priori because a part of the sulphur 

 in the ore thus exposed, becomes converted into sulphuric 

 acid and sulphate of iron, in which state it is washed from 

 the ore by occasional rains. At some of the ore beds and 

 among the rejected heaps at the establishment, this change 

 is actually seen in progress and may be known by a while 

 powdery coating on the ore, having an astringent ink-like 

 flavour. 1 have no doubt that if copperas works were 

 established here, that article of commerce might be obtained 

 at little expense, and with considerable benefit to the iron 

 works, as besides freeing the ore from sulphur, its exposure 

 to the atmosphere to attain that end would render it brittle 

 and more easily broken up for the furnace. 



With regard to the rock associations of this bed, they are 

 seldom seen, as tiie bluff appears to be almost one solid mass 

 of iron ore, but I believe it to be a compact felspar coloured 

 by epidote, as a large mass in my possession, from this 

 place shews that rock traversed by veins of the ore, large 

 masses of crystalline epidote are also seen. The anonymous 

 writer before alluded to thinks that " large unrolled masses 

 *' of granular quartz and coloured by epidote bespeak the 

 " contiguity of that rock in situ," I suspect that the 

 compact felspar above mentioned is what has been mistaken 

 for quartz rock, as of that rock I saw no traces — that which 

 I have ventured to call compact felspar, is certainly not 

 quartz, for it fuses easily with intumescence into a 

 white enamel. 



