The Strange, Grisly History of the First Blood Transfusion
Across many cultures, humans have regarded blood as a substance associated with vitality, renewal, and life itself, centuries before blood transfusions became a viable medical procedure. The idea of restoring health through the transfer of blood predates modern medicine, initially existing more in mythology and ritual than in science. In Homer’s Odyssey, for example, Odysseus briefly revives the shades of the underworld—allowing them to communicate with him—by offering them the blood of a sacrificed animal.
Two scientific breakthroughs made blood transfusion conceivable as a medical treatment: William Harvey’s pioneering description of the circulation of blood through the body, published in 1628, and Christopher Wren’s invention of an apparatus for intravenous injection around 1659. Together, these discoveries established both a theoretical understanding of the circulatory system and a practical means of accessing it. Physicians in England and France soon began experimenting with transfusions between animals, and in 1666 English physician Richard Lower performed the first successful animal-to-animal transfusion.
On June 15, 1667, French physician Jean-Baptiste Denis carried out one of the earliest recorded blood transfusions into a human, transferring a small quantity of lamb’s blood into a feverish teenage boy. The patient survived and appeared to improve, encouraging Denis to continue experimenting with the procedure. A later transfusion performed on another patient also seemed successful at first, fueling hopes that animal blood might be used therapeutically in humans.
Those hopes quickly faded. Subsequent patients became seriously ill, and one man died after repeated transfusions. His widow accused Denis of causing the death, leading to a widely publicized court case. Denis was ultimately cleared of murder, but the controversy sparked growing fear about the dangers of transfusion. Soon afterward, authorities in France, along with organizations such as the Royal Society in England, moved to restrict or discourage the practice.
Blood transfusion largely disappeared from mainstream medicine for nearly two centuries because there was no reliable way to perform the procedure safely before Karl Landsteiner’s discovery of blood groups in 1900–01. It is now known that mixing blood from two non-compatible blood types can trigger a potentially fatal immune reaction. Although the exact cause of death in Denis’s later patients cannot be confirmed, blood incompatibility may have played a role.