In 1819 Laennec1 published the first authentic report of a case of pulmonary gangrene. Subsequently, cases were noted by Leyden and Jaffe2 (1866), who first noted the presence of spirochetes and other bacteria in the sputum and gangrenous tissue of patients suffering from this disease. The work of Rona3 (1905) and especially that of Castellani4 in 1906 attracted the attention of the medical profession to the possible etiologic relationship of the spirochetes to bronchopulmonary lesions. For the next decade heated controversies were waged, especially in France, with regard to the rôle played by the various anaerobes in pulmonary suppuration. A voluminous literature was evolved, filled with hypotheses but surprisingly lacking in experimental and clinical data.
CONCEPTS OF ETIOLOGY IN THE LITERATURE
In 1919 Heuer and Holman5 made the first attempt to produce a pulmonary abscess by placing infected bullets in pulmonary tissue. Following numerous attempts