A study of the last 325 cases at the Presbyterian Hospital, Philadelphia, forms the basis for this article. Almost naturally one thinks of suppuration somewhere as the commonest cause of the persistence of fever after the crisis in pneumonia, though apparently endocardial and pericardial inflammation is a close second.
Among the suppurative cases we found five of empyema, one being interlobar, one encysted and one genuine case of lung abscess which was large enough to be diagnosed antemortem.
An empyema with typical development as illustrated by the following cases makes the diagnosis easy:
—A white woman, aged 47, with typical signs and symptoms of pneumonia involving the lower two-thirds of the left lung, had apparently a crisis (there being a simultaneous fall in temperature, pulse and respiration) on the seventh day, but the temperature immediately went up again, fluctuating between normal and 102 F. The recurrence of