During the 19th century, the addition of the water-seal system to a closed chest drain was a major turning point in the history of thoracic surgery. German physician Gotthard Bülau seems to have invented and used his own closed chest drainage device with a liquid-seal system in 1875, and published it in the year 1891. But, in 1871, British physician William Smoult Playfair seems to have thought of the subaqueous drainage and used such drainage to treat the thoracic empyema in children. The British physician stresses in his texts the effectiveness of his method of fully draining the thoracic empyemas while simultaneously preventing air from entering the pleural cavity. An appropriate honor must be attributed to Playfair, who used a subaqueous chest drainage system and appears to be the first to publish such a method.
Keywords: history of medicine; pediatric surgery; thoracic surgery.