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.
The mandrake is a mythologized plant with a root that looks like a human figure. The root is poisonous and hallucinogenic, it was once a common anesthetic and potion ingredient. Legends say mandrakes scream and cry when uprooted—killing anyone who hears. So use safe harvesting methods! Image: Ernte eines Alrauns (Medicina antiqua), 1250
Depiction of the four humors, the chemical systems believed to regulate human behaviors. According to Hippocrates, who is credited as the first to apply the principle to medicine, the humors were blood, phlegm, yellow bile and black bile. Image: Bartholomaeus Anglicus, mid-15thC