The Fourth Part.

bodies. And yet whilst this is granted, it is affirm’d, but not prov’d, that the reputed Salt, or Sulphur, or Mercury, consists mainly of one body that deserves the name of a principle of the same Denomination. For how do Chymists make it appear that there are any such primitive and simple bodies in those we are speaking of; since ’tis upon the matter confess’d by the answer lately made, that these are not such? And if they pretend by Reason to evince what they affirm, what becomes of their confident boasts, that the Chymists (whom they therefore, after Beguinus, call a Philosophus or Opifex Sensatus) can convince our Eyes, by manifestly shewing in any mixt body those simple substances he teaches them to be compos’d of? And indeed, for the Chymists to have recourse in this case to other proofs then Experiments, as it is to wave the grand Argument that has all this while been given out for a Demonstrative One; so it releases me from the obligation to prosecute a Dispute wherein I am not engag’d to Examine any but Experimentall proofs. I know it may plausibly Enough be Represented, in favour of the Chymists, that it being evident that much the greater part of any thing they call Salt, or Sulphur, or Mercury, is really such; it would be very rigid to deny those Substances the names ascribed them, only because of some sleight mixture of another Body; since not only the Peripateticks call particular parcels of matter Elementary, though they acknowledge that Elements are not to be anywhere found pure, at least here below; And since especially there is a manifest Analogie and Resemblance betwixt the bodies obtainable by Chymical Anatomies and the principles whose names are given them; I have, I say, consider’d that these things may be represented: But as for what is drawn from the Custome of the Peripateticks, I have already told You, that though it may be employ’d against Them, Yet it is not available against me who allow nothing to be an Element that is not perfectly Homogeneous. And whereas it is alledg’d, that the Predominant Principle ought to give a name to the substance wherein it abounds; I answer, that that might much more reasonably be said, if either we or the Chymists had seen Nature take pure