Grunewald's Isenheim Altarpiece served as the starting point for this investigation. On the panel, the viewer encounters a figure with a swollen body, a distorted face, withered arms, and flipper-like feet. After a lengthy discussion, art and medical historical research concluded that this figure should be understood as a victim of ergot poisoning, which was then referred to as St. Anthony's fire. This completes a circle: the altarpiece was commissioned by the Antonites in Isenheim. The main concern of this order was the care and treatment of the victims of ergot poisoning. Following the art historical method, the search for a similar figure in a work of late medieval panel painting was undertaken. No other painter of that time was as frequently engaged with this theme as Hieronymus Bosch (1450-1516). The first attempt was unsuccessful. It was necessary to...