Summary:

The Basil Valentine writings provide twelve "keys", a widely reproduced sequence of alchemical operations encoded allegorically, in words to which images have been added. The first part of the book is a discussion of general alchemical principles and advice about the philosopher's stone. The second half contains twelve short chapters. Each chapter, or "key", is an allegorical description of one step in the process by which the philosopher's stone may be created. With each step, the symbolic names (Deckname, or code name) used to indicate the critical ingredients are changed, just as the ingredients themselves are transformed. The keys are written in such a fashion as to conceal as well as to illuminate: only a knowledgeable reader or alchemical adept was expected to correctly interpret the veiled language of the allegorical text and its related images.