ed through a comparatively small
canal. If the canal becomes obstructed during esophagoscopy, the
positive pressure tube of the aspirator is used to blow out the
obstruction. Two sizes of esophagoscopes are all that are required--7
mm. X 45 cm. for children, and 10 mm. X 53 cm. for adults (Fig. 3, A
and B); but various other sizes and lengths are used by the author for
special purposes.* Large esophagoscopes cause dangerous dyspnea in
children. If, it is desired to balloon the esophagus with air, the
window plug shown in Fig. 6, is inserted into the proximal end of the
esophagoscope, and air insufflated by means of the hand aspirator or
with a hand bulb. The window can be replaced by a rubber diaphragm
with a perforation for forceps if desired. It will be noted that none
of the endoscopic tubes are fitted with mandrins. They are to be
introduced under the direct guidance of the eye only. Mandrins are
obtainable, but their use is objectionable for a number of reasons,
chief of which is the danger of overriding a foreign body or a lesion,
or of perforating a lesion, or even the normal esophageal wall. The
slanted end on the esophagoscope obviates the necessity of a mandrin
for introduction. The longer the slant, with consequent acuting of the
angle, the more the introduction is facilitated; but too acute an
angle increases the risk of perforating the esophageal wall, and
necessitates the utmost caution. In some foreign-body cases an acute
angle giving a long slant is useful, in others a short slant is
better, and in a few cases the squarely cut-off distal end is best. To
have all of these different slants on hand would require too many
tubes. Therefore the author has settled upon a moderate angle for the
end of both esophagoscopes and bronchoscopes that is easy to insert,
and serves all purposes in the version and other manipulations
required by the various mechanical problems of foreign-body
extraction. He has, however, retained all the experimental models, for
occasional use in such cases as he falls heir to because of a problem
of extraordinary difficulty.

* A 9 mm. X 45 cm. esophagoscope will reach the stomach of almost all
adults and is somewhat easier to introduce than the 10 mm. X 53 cm.,
which may be omitted from the set if economy must be practiced.

[FIG. I.--Author's laryngoscopes. These are the standard sizes and
fulfill all requirements. Many other forms have been devised by the
author, but have been omit