One of Napoleon’s leading surgeons, Percy laid down his principles of the practice of military surgery in the same year he was appointed médecin consultant of the Army of the North. He devised his own instrument for bullet extraction, the tribulcon. He was responsible, with Larrey, for the invention of special ambulances and squads of litter-bearers, including a “super-ambulance” capable of carrying 8 surgeons, 8 attendants, and dressings for 1200.