compounded Nature. And indeed I scarce know any one Mineral, from which by Fire alone Chymists are wont to sever any Substance simple enough to deserve the name of an Element or Principle. For though out of native Cinnaber they distill Quicksilver, and though from many of those Stones that the Ancients called Pyrites they sublime Brimstone, yet both that Quicksilver and this Sulphur being very often the same with the common Minerals that are sold in the Shops under those names, are themselves too much compounded Bodies to pass for the Elements of such. And thus much, Eleutherius, for the Second Argument that belongs to my First Consideration; the others I shall the lesse insist on, because I have dwelt so long upon this.
Proceed we then in the next place to consider, That there are divers Separations to be made by other means, which either cannot at all, or else cannot so well be made by the Fire alone. When Gold and Silver are melted into one Mass, it would lay a great Obligation upon Refiners and Goldsmiths to teach them the Art of separating them