The disastrous results which sometimes follow simple open drainage of empyemas have induced a number of experimental and practical workers to undertake improved methods of treating such cases. These bad results consist in the failure of healing; in the formation of fistulas leading down to large cavities, often persisting for years after incision and drainage; osteomyelitis of ribs; retracting of connective tissue about the pleura, resulting in distortion of the thoracic viscera; infection with tubercle bacilli; secondary and remoter conditions such as amyloid degeneration and intercurrent diseases; and especially the distortions of the skeleton and the distant musculature due to the contraction and collapse of the chest walls. Most of these consequences are due to the mechanical conditions under which healing has to take place.
When the pleural cavity is widely opened the lung, on account of its elastic tissue, retracts immediately toward its root. During expiration there is a