Printed during the Wanli period, Ben cao gang mu (Compendium of materia medica) is a work on an encyclopedic scale, in 52 juan of text with two juan of illustrations, in 25 volumes. It was compiled by Li Shizhen (circa 1518–93), a native of Sichuan, who was one of the greatest physicians, pharmacologists, and naturalists in Chinese history. After serving for only one year in the prestigious Imperial Medical Institute, Li returned home to work as a doctor and to begin writing this book. The work and its three revisions took 27 years to complete. The exact date of publication is unknown. Li collected the material by meticulously surveying hundreds of sources in the years 1552–78. He travelled extensively and gathered first-hand experience with herbs and local remedies throughout China, as well as consulted every medical book in print at the time. The result was this work of great scientific, medical, and historical significance. The compendium contains details on approximately 1,800 medicinal drugs, including previously unknown varieties, with illustrations and some 11,000 prescriptions. Each herb is described by its type, form, flavor, nature, and method of application. The work was reissued many times during the Qing dynasty (1644–1911) and since then. It has been translated into many languages, and is still considered the premier reference tool for Chinese herbal medicine. Also included are discussions on such related subjects as botany, zoology, mineralogy, and metallurgy. The author grouped his material into the categories of animal, mineral, and plant. Also included is a bibliography of 900 or so book titles. A label indicates that this copy was originally owned by Fujiyama of Izumo. The corrections, written in red ink on the top margins, were made by the Japanese medical scholar, Mori Tatsuyuki. The preface, dated 1590, is by Wang Shizhen (1526–90), a preeminent man of letters and historian of the Ming dynasty.