85. Whether the produced Metal be all of the same goodness? And if it be, how good it is in reference to the Metal of other Mines, or other parts of the same Mine or Vein? And if it be not, what differences are observ'd between the produced portions of Metal; and what disparity that amounts to in the price?
86. What are the Wayes of distinguishing them, and estimating their goodness?
87. Whether they do any thing to the Metal, after it is once brought to Fusion, and, if need be, melt it over again, to give it a melioration? (As when Iron is refined, and turn'd into Steel;) And what distinct Furnaces, and peculiar Ways of ordering the Metals are employ'd to effect this improvement? With a full description of them and the Tools in all Circumstances, observ'd in the refining of Metals.
88. Whether in those places, where the Metal is melted, there be not elevated some Corpuscles, that stick to the upper parts of the Furnace, or Building? And, if there be, whether they be barely fuliginous and recrementitious exhalations, or, at least in part, Metallin Flowers? (As in the Cornish Tin-mines, after some years they usually destroy the thatch'd Houses, where the Ore hath been melted, to get the stuff, that adhears to the insides of the Roofs, out of which they melt store of excellent Tin.)
89. Whether the Metal, being brought to fusion, affords
any Recrements? (As Iron-stone affords store of a dark Glass or Slagg) And, if it do, what those Recrements are? How they are separated from the Metal; and to what Uses they are employed?
90. Whether, after the Metal has been once melted, the remaining part of the Ore being exposed to the Air, will in tract of time be impregnated, or ripen'd, so as to afford more Metal? (For, this is affirm'd to me of the Cornish Tin-Ore; and what remained after the fusion of Iron-ore in the Forest of Dean, is so rich in Metal, that a Tenant of mine in Ireland, though he had on the Land, he held from me, an Iron-Mine, found it less profit to work it, than to send cross the Sea to the Forest of Dean for this already us'd Ore, which having lain for some ages, since it was thrown aside in great heaps expos'd to the Air, he affirm'd to yield as well great great store of Iron, as very good: though I somewhat doubt, whether this be totally to be ascribed to the Aire, and length of time; or to the leaving of Metal in the Slaggs in old times, before great Furnaces were in use.)
Promiscuous Inquiries about Mines, from the same Author.
1. Whether the Territorie, that bears the Mine, abounds with no other Kind of Mineral in some distinct part of it? (As in Kent near Tunbridge, one part of the Country which is Hilly, abounds all along with Iron-Mines; the other, which is also Hilly, and divided from it but by a small Valley, abounds exceedingly (as the Diggers and Inhabitants told me upon the place) in Quarry's, which the Metallin-Country wants, but is quite destitute of Iron-stone. And so at Mendip, in one part of the Hill, I saw store of Lead-Mines, containing several Kinds of Ore of that Metal; another part of the Hill I found to be full of Cole-pits, which had some Marchasites, but no Metal; and in another place, Iron-ore, and mixt Ores, which yet they did not think fit to work.)