Human dissection, 14th century artwork from Anathomia (1345), by anatomist Guido da Vigevano. This chap was the first person to provide anatomical drawings in his manuscripts. He also pioneered standing dissections, picture here.
The Black Hours, 1475. A book of hours produced in an unusual way with blackened margins and vellum. Produced in Bruges in the studio of Willem Vrelant. Now in the possession of the Pierpont Morgan Library, NY.