Since the middle of the 17th century, doctors tried to perform the first blood transfusions between animals, but no one dared to experiment on humans. The English who described blood circulation at that time remained reluctant to take such a decision, and the French Academy of Sciences prevented its members from embarking on such an adventure. However, a French man dared to inject the blood of a lamb into the veins of a 15-year-old boy.
The magazine Le Point French , in a joint report between Frédéric Luino and Gwendolyn dos Santos, said that the man who did this act, Jean-Baptiste Denis (28 years old at the time), was famous for giving lectures on mathematics, physics and medicine at his home in Paris. He claimed to be a graduate of the faculties of medicine in Montpellier and Reims, but no trace of him was found in their archives, and no trace of his alleged degrees in mathematics and philosophy were found