and very lasting: yet it will not necessarily follow, that because the Fire was able at length to make the Silver lose a little of its weight, it was therefore able to dissipate it into its Principles. For first I might alledge that I have observ’d little Grains of Silver to lie hid in the small Cavities (perhaps glas’d over by a vitrifying heat) in Crucibles, wherein Silver has been long kept in Fusion, whence some Goldsmiths of my Acquaintance make a Benefit by grinding such Crucibles to powder, to recover out of them the latent particles of Silver. And hence I might argue, that perhaps Claveus was mistaken, and imagin’d that Silver to have been driven away by the Fire, that indeed lay in minute parts hid in his Crucible, in whose pores so small a quantity as he mist of so ponderous a Bodie might very well lie conceal’d.
But Secondly, admitting that some parts of the Silver were driven away by the violence of the Fire, what proof is there that it was either the Salt, the Sulphur, or the Mercury of the Metal, and not rather a part of it homogeneous to what remain’d? For besides, that the Silver that was left seem’d not sensibly alter’d, which probably would have appear’d, had so much of any one of its Principles been separated from it: We finde in other Mineral Bodies of a less permanent nature than Silver, that the Fire may divide them into such minute parts, as to be able to carry them away with its self, without at all destroying their Nature. Thus we see that in the refining of Silver, the Lead that is mix’d with it (to carry away the Copper or other ignoble Mineral that embases the Silver) will, if it be let alone, in time evaporate away upon the Test; but if (as is most usual amongst those that refine great quantities of Metals together) the Lead be blown off from the Silver by Bellowes, that which would else have gone away in the Form of unheeded steams, will in great part be collected not far from the Silver, in the Form of a darkish Powder or Calx, which, because it is blown off from Silver, they call Litharge of Silver. And thus AgricolaAgricola de Natura Fossil. Lib. 9. Cap. 11. & 12. in divers places informs us, when Copper, or the Oare of it is colliquated by the violence of the Fire with Cadmia, the Sparks that in great multitudes do fly upwards do,