SPAGYRIST'S PRINCIPLES Commonly call'd HYPOSTATICAL , As they are wont to be Propos'd and Defended by the Generality of ALCHYMISTS . Whereunto is prAEmis'd Part of another Discourse relating to the same Subject. BY The Honourable ROBERT BOYLE , Esq; LONDON, Printed by J. Cadwell for J. Crooke , and are to be Sold at the Ship in St. Paul's Church-Yard. MDCLXI .