But, before I enter any farther into this Disquisition, I cannot but here take notice, that it were to be wish’d, our Chymists had clearly inform’d us what kind of Division of Bodies by Fire must determine the number of the Elements: For it is nothing near so easy as many seem to think, to determine distinctly the Effects of Heat, as I could easily manifest, if I had leasure to shew you how much the Operations of Fire may be diversify’d by Circumstances. But not wholly to pass by a matter of this Importance, I will first take notice to you, that Guajacum (for Instance) burnt with an open Fire in a Chimney, is sequestred into Ashes and Soot, whereas the same Wood distill’d in a Retort does yield far other Heterogeneities, (to use the Helmontian expression) and is resolv’d into Oyl, Spirit, Vinager, Water and Charcoal; the last of which to be reduc’d into Ashes, requires the being farther calcin’d then it can be in a close Vessel: Besides having kindled Amber, and held a clean Silver Spoon, or some other Concave and smooth Vessel over the Smoak of its Flame, I observ’d the Soot into which that Fume condens’d,
