The Syriac Galen Palimpsest (SGP), a privately owned manuscript containing parts of books 2-9 of Galen’s Simple Drugs in Syriac translation, offers important evidence to the reconstruction of the Greek text of book 9. Roughly half the book survives in it, and the article discusses the methodology used to reconstruct the often poorly visible Syriac text, combining computational tools for text and image analysis. In particular, the creation of a lemmatised bilingual Greek-Syriac corpus provides an important heuristic tool for the reconstruction of the text. The Syriac version of two chapters from book 9, ‘on stones in sponges’ and ‘on ostracite’, are edited here for the first time and used to illustrate the challenges and the opportunities that the SGP offers not just for the study of the Greek textual history, but also the transmission from Greek into Arabic