Twelve Keys of Basil Valentine is one of the most important alchemical works available to modern students of Alchemy and early Chemistry. First published in Ein kurtz summarischer Tractat, von dem grossen Stein der Uralten... (Eisleben, 1599) without illustrations, it achieved wider distribution as part of the Tripus Aureus (Golden Tripod) compendium edited by Michael Maier and published at Frankfurt in 1618 by Lucas Jennis. Maier's illustrated edition of the work is by far the most influential. The emblematic engravings drew upon the allegorical descriptive imagery of the text and added coherence to the symbolism.