Although his primacy was subsequently challenged by a student, it is now known that Johann Georg Wirsüng, the prosector of Padua, Italy, discovered the human pancreatic duct in 1642 during the dissection of an executed murderer. Instead of publishing his discovery, he engraved a drawing of the duct on a copper plate, from which he made seven or more imprints. The copies were sent to leading anatomists of Europe with the question, "Should I call it an artery or a vein? I never found blood in it ...." Three and a half centuries later, the copper plate remains well preserved and the authors, to the surprise of European surgeons and librarians, but with their aid, have traced six copies of the "ductus Wirsüngianus" imprints still in existence. This is the story of Wirsüng the man, his subsequent assassination, and finally the recognition that his finding had opened a new field of science.