The Sceptical Chymistor Chymico-Physical Doubts &amp; Paradoxes, Touching the Spagyrist's Principles Commonly call'd Hypostatical; As they are wont to be Propos'd and Defended by the Generality of Alchymists. Whereunto is præmis'd Part of another Discourse relating to the same Subject. by Boyle, Robert
 is a Project Gutenberg book, now on Github.