Jean Louis Petit (Paris 1674 - 1750 therein), graduated in 1700, became a member of the Academy of Sciences in 1715 and director of the Royal Surgical Academy in 1731. He opened a private surgery school in Paris where his lessons, especially in traumatology they gained great fame. His most important research concerns haemorrhage and hemostasis, fractures, dislocations, lacrimal fistulas and Achilles tendon injuries. He designed and built a shower for the immobilization of the lower limb. He was the inventor of the tourniquet.