Page:Philosophical Transactions - Volume 001.djvu/357

 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.)

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, which yet they did not think fit to work.)

2. Whether the Air appear to be really cold in Summer, Rh