Written about 970 CE, this is the earliest surviving medical treatise written in Hebrew to which an approximate date can be assigned. Donnolo, who was at one time Byzantine court physician, is one of the earliest Jewish writers on medicine, and one of the few medieval Jewish scholars of South Italy at this early time. What remains of his medical work, Sefer ha-Yaá¸³ar (Precious Book), was published by Moritz Steinschneider in 1867, from MS. 37, Plut. 88, in the Medicean Library at Florence. It contains an "antidotarium," or book of practical directions for preparing medicinal roots. Donnolo's medical science is based upon Greco-Latin sources; only one Arabic plant-name occurs. Donnolo is also the earliest known authority to quote the Sefer Refuot , of Asaph ben Berechiah, the earliest known Hebrew medical author. Digital facsimile from Google Books at this link.