In recent years, the subject of postoperative pneumonia has received more and more the attention which it deserves. Especially important among the communications on this subject are those by Whipple1 and by Cleveland,2 from the Presbyterian Hospital in New York; Cutler and Morton,3 and Cutler and Hunt,4 from the Peter Bent Brigham Hospital, and Mandl5 from Hochenegg's clinic in Vienna. All these papers review the literature, and the one by Cutler and Hunt gives a complete bibliography.
These papers are interesting not only for their presentation of the statistical incidence of postoperative pneumonia, but also for the ideas which the authors express as to the cause of this complication. Whipple found ninety-seven cases of postoperative pneumonia, or 2.3 per cent., following 3,719 operations; Cleveland, sixty-five cases, or 3.3 per cent. of 1,940 cases; Cutler and Hunt, sixty-three cases of pulmonary complications, or 3.92 per