The etiology of pulmonary suppuration and allied conditions has been the subject during the last few years of a number of intensive investigations. A number of clinical and experimental studies have appeared in the literature. The difficulty of producing inflammatory and suppurative processes in animals by the bronchial route has long been recognized; on the other hand, such processes are easily initiated by way of the circulation by the introduction of infected material into the veins, as has been demonstrated by Cutler and others. Pulmonary abscesses following tonsillectomies—the postoperative abscess—stimulated much of this work. Such an abscess forms the greater number of those occurring in the lung, and, if they form as the result of aspiration, should have quite a different pathogenesis from those caused by the introduction of infectious material into the veins.
Abscesses following tonsillectomy constitute almost 50 per cent of all postoperative abscesses of the lung. If