After the recent identification of the author of the K. Rutbat al-ḥakīm as Maslama al-Qurṭubī (d. 353/964) the value of this book for the history of alchemy/chemistry can be fully appreciated. Maslama was the first author to quote the Arabic Tome of Pictures (Muṣḥaf al-ṣuwar) of the Egyption alchemist Zosimos of Panopolis. He must have received a copy of this work from a center of alchemical learning in the western Maġrib. For its location the salt mining town Taġāza may tentatively be proposed. A large part of Maslama’s book deals with the rumūz, the symbolic language and puzzling expressions employed by the alchemists. He distinguishes between the rumūz used by the pre-Islamic alchemists and those used by the Arab alchemists beginning with Ǧābir b. Ḥayyān.