Before July 20, 1467 Adolf Rusch, the "R" printer, of Strasbourg, issued the first printed edition of De sermonum proprietate, seu de universo, written by Hrabanus Maurus (Rabanus Maurus), Archbishop of Mainz in the first half of the ninth century. This was the first printed encyclopedia, and the first printed book to contain a chapter on medicine. That section may also be the first significant printed text on a scientific subject.
"Dating is based on a MS. note in a copy at Paris BN (cf. CIBN). P. Needham in Christie's, Doheny 16, disputes the date, placing the types 1473-75 and regarding Mentelin in association with Rusch as responsible for the work of the R-printer."