Three Newly-Discovered Copies of the Manuscript Mayaku Ko, Written by Shutei Nakagawa, with Special Reference to their Appearance and Genealogy.

: Seishu Hanaoka's greatest achievement was the anesthetic Mafutsusan. He developed it and then used it successfully for various operations, primarily breast cancer tumor excisions. The developmental process can be traced in Mayaku Ko, a memorandum written and edited in 1796 by Hanaoka's close friend Shutei Nakagawa. Contained in this document is a list of fourteen prescriptions for earlier attempts by other doctors to create-a general anesthetic. These prescriptions, which Nakagawa had passed along to Hanaoka, were the foundation for the scientific breakthrough. The preface suggests that Hanaoka had nearly perfected Mafutsusan by 1796. Nakagawa's original manuscript has been lost, but copies of it are extant. Until recently, we knew of four, all of them in Japan. I have discovered three more: one in the University of Tokyo Library (Gakken Collection), another in the Keio University Shinanomachi Media Center, and the third in the Asahikawa Medical University Library (Sekiba-Samejima Collection). After carefully examiiing the new ones, I put the seven known copies of Mayaku Ko into four groups, A to D, according to the order in which they were likely transcribed. One of the copies in Group A, which is from the Matsuki Collection, appears to have been the first.