913 - 982 SHABBETAI (Abraham) DONNOLO (Italy)
Earliest Jewish author on medicine. His manuscript, Sepher Hamirkachot (or Sefer Hayakar) (Book of Remedies), is based on vegetarian preparations in the Greek tradition. Despite his reputation, his friend St. Nilus refused to use his medicine lest it be said that a Jew cured him. Donnolo was also a noted astrologer and composed a commentary on the mystical Sepher Yetzirah (Book of Creation) called Tachkemoni in which he discussed the mystical significance of the Hebrew letters as well his reasons against discussing the "image of God".