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 Salt, pure Sulphur, and pure Mercury, and compound of them every sort of Mixt Bodies. But, since 'tis to experience that they appeal, we must not take it for granted, that the Distill'd Oyle (for instance) of a plant is mainly compos'd of the pure principle call'd Sulphur, till they have given us an ocular proof, that there is in that sort of Plants such an Homogeneous Sulphur. For as for the specious argument, which is drawn from the Resemblance betwixt the Productions of the Fire, and the Respective, either _Aristotelian_ Elements, or _Chymical_ Principles, by whose names they are call'd; it will appear more plausible then cogent, if You will but recall to mind the state of the controversie; which is not, whether or no there be obtain'd from mixt Bodies certain substances that agree in outward appearance, or in some Qualities with Quicksilver or Brimstone, or some such obvious or copious Body; But whether or no all Bodies confess'd to be perfectly mixt were compos'd of, and are resoluble into a determinate number of primary unmixt Bodies. For, if you keep the state of the question in your Eye, you'l easily discerne that there is much of what should be Demonstrated, left unprov'd by those Chymical Experiments we are Examining. But (not to repeat what I have already discover'd more at large) I shall now take notice, that it will not presently follow, that because a Production of the Fire has some affinity with some of the greater Masses of matter here below, that therefore they are both of the same Nature, and deserve the same Name; for the Chymists are not content, that flame should be look't upon as a parcel of the Element of Fire, though it be hot, dry, and active, because it wants some other Qualities belonging to the nature of Elementary fire. Nor will they let the Peripateticks call Ashes, or Quicklime, Earth, notwithstanding the many likenesses between them; because they are not tastlesse, as Elementary Earth ought to be: But if you should ask me, what then it is, that all the Chymical Anatomies