No. 13. The Book of CratèsThe Book of Cratès is a ninth century alchemical text in Arabic, now preserved in only one extant manuscript, is not, in fact, a work of Arabic alchemy, although it has a short preface obviously written by an Islamic editor, and there is a short section at the end which mentions Khalid ben Yezir, who is supposed to have introduced alchemy to Islam through meeting the legendary Morienus, as recounted in the Liber de compostione alchimiae.
The text of the Book of Cratès is actually of Greek origin, much of it being imbued with the spirit of Graeco-Egyptian alchemy. At one point it quotes one of the precepts of Democritus "Nature delights in Nature", and those with a deep knowledge of Greek alchemy will find quotations or borrowings from Bolos of Mendes (second century B.C.), and probably from Ostanes. Ostanes was especially obsessed with the need for secrecy and this is a strong theme of the narrative of the Book of Cratès. Ostanes also in one of his works The book of the Thirty Chapters, uses the idea of falling asleep and being taken up in a dream where he meets an old man (a Hermes Trismegistus figure), as we find in the Book of Cratès.
Whatever the origins of this little book the ideas it presents are those which still shaped the alchemy of Northern Europe through the early modern period and well into the 17th and even 18th centuries. The use of allegory and the frustration of having the secret concealed by the writer of a text, common themes in the later period, are so cogently presented in this 9th century work.