the left forefinger. As soon as the instrument engages in the
opening of the oesophagus, the chin is brought down towards the chest,
and if the patient is now directed to swallow, the instrument may be
carried down the oesophagus, or can be passed on by gentle pressure.
Great gentleness must be exercised, and no attempt should be made to
force the instrument past any obstruction. The instrument may catch
against the hyoid bone, and this may be mistaken for an obstruction.

It is to be borne in mind that in some cases the passage of a bougie
may be attended with a considerable degree of shock, and cases are on
record in which this has proved fatal without any gross lesion being
found after death.

_Intubation_, or the passage of a cannula through a stricture, is
referred to later.

_Oesophagoscopy._--The _oesophagoscope_--a form of speculum which
enables the oesophagus to be illuminated by an electric lamp--is
employed for the detection and removal of foreign bodies, for the
examination of ulcers, diverticula, and strictures of the tube, and
with its aid it is possible to remove a portion of a growth for
microscopic examination. The mouth, pharynx, and entrance to the
oesophagus having been cleansed and cocainised, the patient is placed
in the recumbent or sitting posture, and the tube introduced. For
prolonged examinations a general anaesthetic is preferred.

The mouth of the oesophagus is closed by the sphincter-like action of
the lower fibres of the inferior constrictor muscle, and the cervical
part of the tube appears as a transverse slit, due to the backward
pressure of the trachea. The thoracic portion is more open and may
contain air, so that it is possible to see down to the lower end, the
closed cardiac orifice appearing as an oblique cleft surrounded by a
rosette-like cushion of mucous membrane. The pulsation of the aorta
can be seen just above the prominence formed by the left bronchus.

_Radiography._--Opaque foreign bodies can be detected by the screen or
in a radiogram; and the position of a stricture by making the patient
swallow capsules containing bismuth and examining with the screen. To
determine the position and size of a diverticulum, a radiogram is
taken after the patient has swallowed some food, such as porridge
mixed with bismuth.

#Wounds# of the oesophagus inflicted from without, for example stabs,
cut-throat or gun-shot injuries, are rare, and are almost invariably
accompanied by lesion