The Four Books of pseudo-Democritus, written in the first century AD, rank among the very earliest known alchemical writings. In this volume, Matteo Martelli presents not only a fresh edition and translation of the surviving Greek fragments, but also, for the first time, additional materials preserved in Syriac.The volume presents important examples of the early modern and medieval reception of Synesius and Dioscorus - the most interesting Byzantine commentary on the Four Books - and previously unpublished Latin translations of both the Four Books and Synesius' commentary made by Matthaeus Zuber in 1606. Accompanied by a full translation and commentary, these sources offer new and significant insights into the world of ancient chemistry: practical recipes and lists of ingredients, clues to the doctrinal content of ancient alchemy, and early hints of a tradition that linked the alchemist 'Democritus' to the wisdom of Egypt and Persia.