According to Heyde, the ancients practiced pericardial incision, but in the opinion of Burtenshaw, meagerness of the reports vitiates their acceptance as genuine examples of this operation. It is said that Galen removed the sternum and anterior wall of the pericardium from a soldier in whom a neglected wound of the chest had led to the development of a suppurative pericarditis and by this means obtained a cure. It is definitely known, however, that as early as 1648, Riolanus advised trephinement of the sternum for drainage of the pericardium. In 1818, Skielderup repeated Riolanus' suggestion, but it was not put into practice until 1855, when Malle evacuated a hemopericardium successfully through an opening in the sternum. The first and only instance of draining a pyopericardium by this route that we could locate in the literature is the case reported by Bexman, in 1891, with recovery of his patient. Four of