empyema nearly always clear up any difficulty promptly. The absence of
the frequent change in the voice sounds, so significant in an early
small empyema, is of value. A large empyema should give no difficulty.
If difficulty remains the use of the needle should be sufficient. In
thickened pleura vocal fremitus is not entirely absent, and the
breath-sounds can usually be heard, even if diminished. In case of
partial obstruction of a bronchus, it is evident that air will still
be present, hence the dulness may be only slight. The presence of air
and secretion will probably result in the breath-sounds being somewhat
harsh, and will cause a great variety of rales, principally coarse,
and many of them bubbling. Difficulty may be caused by signs in the
other lung or in a lobe other than the one affected by the foreign
body. If it is remembered that these signs are likely to be only on
auscultation, and to consist largely in the presence of rales, while
the signs in the area supplied by the affected bronchus will include
those on inspection, palpation, and percussion, there should be little
difficulty."

_The roentgenray_ is the most valuable diagnostic means; but careful
notation of physical signs by an expert should be made in all cases
preferably without knowledge of ray findings. Expert ray work will
show all metallic foreign bodies and many of less density, such as
teeth, bones, shells, buttons, etcetera. If the ray is negative, a
diagnostic bronchoscopy should be done in all cases of unexplained
bronchial obstruction.

Peanut kernels and watermelon seeds and, rarely, other foreign bodies
in the bronchi produce obstructive emphysema of the invaded side.
Fluoroscopy shows the diaphragm flattened, depressed and of less
excursion on the invaded side; at the end of expiration, the heart and
the mediastinal wall move over toward the uninvaded side and the
invaded lung becomes less dense than the uninvaded lung, from the
trapping of the air by the expiratory, valve-like effect of
obliteration of the "forceps spaces" that during inspiration afford
air ingress between the foreign body and the swollen bronchial wall.
This partial obstruction causes obstructive emphysema, which must be
distinguished from compensatory emphysema, in which the ballooning is
in the unobstructed lung, because its fellow is wholly out of function
through complete "corking" of the main bronchus of the invaded side.

_Esophageal Foreign Body_.--After ini