mach for
esophagoscopy and gastroscopy. Vomiting is soon followed by relaxation
and stupor. The dog is normal and hungry in a few hours. Dosage must
be governed in the clog as in the human being by the susceptibility to
the drug and by the temperament of the animal. Other forms of
anesthesia have been tried in my teaching, and none has proven so safe
and satisfactory. Phonation may be prevented during esophagoscopy by
preventing approximation of the cords, through inserting a silk-woven
cathether in the trachea. The larynx and trachea may be painted with
cocain solution if it is found necessary for bronchoscopy. A very
comfortable and safe mouth gag is shown in Fig. 73. Great gentleness
should be exercised, and no force should be used, for none is required
in endoscopic work; and the endoscopist will lose much of the value of
his dog practice if he fails to regard the dog as a child. He should
remember he is not learning how to do endoscopy on the dog; but
learning on the dog how safely to do bronchoscopy on a human being.
The degree of resistance during introduction can be gauged and the
color of the mucosa studied, while that interesting phenomenon, the
dilatation and lengthening of the bronchi during inspiration and their
contraction and shortening during expiration, is readily observed and
always forms subject for thought in its possible connection with
pathological conditions. Foreign body problems are now to be solved
under these living conditions, and it is my feeling that no one should
attempt the removal of a foreign body from the bronchus of a child
until he has removed at least 100 foreign bodies from the dog without
harming the animal. Dogs have the faculty of easily ridding their
air-passages of foreign objects, so that one need not be alarmed if a
foreign body is lost during practice removal. It is to be remembered
that dogs swallow very large objects with apparent ease. The dog's
esophagus is relatively much larger than that of human beings.
Therefore a small dog (of six to eight pounds' weight) must be used
for esophagoscopic practice, if practice is to be had with objects of
the size usually encountered in human beings. The bronchi of a dog of
this weight will be about the size of those of a child.

[FIG. 73.--Author's mouth gag for use on the dog. The thumb-nut serves
to prevent an uncomfortable degree of expansion of the gag. A bandage
may be wound around the dog's jaws to prevent undue spread of the