The Philosophers' Stone is unique, and one, but hidden and veiled in a multiplicity of different names, and before knowing it you will have seen much struggle: only with difficulty will you come to know it by your own genius. It is watery, airy, fiery and earthy, phlegmatic, choleric, sanguine and melancholy. It is a sulphur and equally Quick Silver. - The GREAT John Pontanus, The Epistle on the Philosophic Fire