Ceration is a chemical process, a common practice in alchemy. Pseudo-Geber's Summa Perfectionis explains that ceration is "the mollification of an hard thing, not fusible unto liquefaction", and stresses the importance of correct humidity in the process.  Ceration is performed by continuously adding a liquid by imbibition to a hard, dry substance while it is heated. Typically, this treatment makes the substance softer, more like molten wax. 
Antoine-Joseph Pernety's 1787 mytho-Hermetic dictionary defines it somewhat differently as the time when matter passes from black to gray, and then to white. Continuous cooking effects this change.  Ceration may be synonymous with similar terms for alchemical burning processes. Incineration, for example is listed by Manly P. Hall. (Also see Calcination.)
- Stanton J. Linden. The alchemy reader: from Hermes Trismegistus to Isaac Newton. Cambridge. 2003. pg 93.
- Martinus Rulandus. Lexicon of Alchemy. 1612
- Antoine-Joseph Pernety. Dictionnaire mytho-hermétique, dans lequel on trouvre les allégories fabuleuses des poètes, les métaphores, les énigmes et les termes barbares des philosophes hermétiques expliqués. 1787 p.70
- Manly P.Hall. The Secret Teachings of All Ages. Los Angeles. 1928. p. 507