Popes, Scandal, and Blood Transfusions

From Wikipedia:

Papist and other Catholic authors take pains to discredit the story of Innocent VIII's deathbed [by Stefano Infessura]. As the Pope sank into a coma, "the harrowing story was told that, at the suggestion of a Jewish physician, the blood of three boys was infused into the dying pontiff’s mouth (the concept of circulation and methods for intravenous access did not exist at that time). They were ten years old, and had been promised a ducat each. All three died." Historians of medicine note this event as the first recorded historical attempt at a blood transfusion.