As for silver, I never could see any degree of fire make it part with any of its three principles. ...But admitting, that some parts of the silver we… - Robert Boyle

[T]hat which I am now entering upon being the Consideration of the things themselves whereinto Spagyrists resolve mixt Bodies by the Fire, If I can shew that these are not of an Elementary Nature, it will be no great matter what names these or those Chymists have been pleased to give them. And I question not that to a Wise man, and consequently to Eleutherius, it will be lesse considerable to know, what Men Have thought of Things, then what they Should have thought.

And that you may know... what kind of writings I mean, I shall name to you the learned Gassendus his little Syntagma of Epicurus's philosophy, and that most ingenious gentleman Monsieur Descartes his principles of philosophy. For though I purposely refrained, though not altogether from transiently consulting about a few particulars, yet from seriously and orderly reading over those excellent (though disagreeing) books, or so much as Sir Francis Bacon's Novum Organum, that I might not be prepossessed with any theory or principles, till I had spent some time in trying what things themselves would incline me to think; yet beginning now to allow myself to read those excellent books, I find by the little I have read in them already, that if I had read them before I began to write, I might have enriched the ensuing essays with divers truths, which they now want, and have explicated divers things much better than I fear I have done.

A Person any Thing vers’d in the Writings of Chymists cannot but Discern by their obscure, Ambiguous, and almost Ænigmatical Way of expressing what they pretend to Teach, that they have no Mind, to be understood at all, but by the Sons of Art (as they call them) nor to be Understood even by these without Difficulty And Hazardous Tryalls.