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 {342} 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.)

2. Whether the Air appear to be really cold in Summer, {343} and hot in
Winter at the bottom of the Min