The Antikamnia Chemical Company created these morbid calendars in the late 19th century and early 20th century to promote their pain killers to druggists. While their products were effective, they were revealed to contain a banned—and poisonous—ingredient, acetanilid. Images: Wellcome Library
The medieval wound man, first appearing in the 15th century, was used by physicians and surgeons to communicate anatomy and how to heal different ailments. The diagrams showed the location of diseases, blood letting points, and anatomical correspondences to zodiac signs. Sources and more info on the Public Domain Review.