The history of blood transfusion is probably longer than that of any other therapeutic procedure. In 1654 Francesco Folli of Florence reported the successful administration of blood transfusion to animals, and Denis of France in 1667 performed the first reported blood transfusion on a man, injecting the blood of a lamb. Owing to the serious reactions that followed blood transfusions, they were prohibited by law in France and in Britain in 1670. It was not until 1901 that the remarkable work of Landsteiner, proving the presence of isohemoagglutinins in human bloods, resulted in the grouping of bloods and thus the therapeutic value of blood transfusions became accepted.