The Fourth Part.

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 of Bodies do prove, if they prove not that they consist of the three Principles into which the fire resolves them? I answer, that their Dissections may be granted to prove, that some mixt bodies (for in