A PRÆFACE INTRODUCTORY To the following Treatise.

give those that shall read them other thoughts of me: & I had a design (but wanted opportunity) to publish with these Papers an Essay I have lying by me, the greater part of which is Apologetical for one sort of Chymists. And at least, as for those that know me, I hope the pain I have taken in the fire will both convince them, that I am far from being an Enemy to the Chymists Art, (though I am no friend to many that disgrace it by professing it,) and perswade them to believe me when I declare that I distinguish betwixt those Chymists that are either Cheats, or but Laborants, and the true Adepti; By whom, could I enjoy their Conversation, I would both willingly and thankfully be instructed; especially concerning the Nature and Generation of Metals: And possibly, those that know how little I have remitted of my former addictedness to make Chymical Experiments, will easily believe, that one of the chief Designes of this Sceptical Discourse was, not so much to discredit Chymistry, as to give an occasion and a kind of necessity to the more knowing Artists to lay aside a little of their over-great Reservedness, &