endoscopist may precede each case with a practical experience
equivalent to any number of cases of precisely the same kind of
foreign body. If the object cannot be removed from the rubber tube
without violence, it is obvious that no attempt should be made on the
patient until further practice has shown a definite method of harmless
removal. During practice work the value of the beveled lip of the
bronchoscope and esophagoscope in solving mechanical problems will be
evidenced. With it alone, a foreign body may be turned into favorable
positions for extraction, and folds can always be held out of the way.
Sufficient combined practice with the bronchoscope and the forceps
enable the endoscopist easily to do things that at first seem
impossible. It is to be remembered that lateral motion of the long
slender tube-forceps cannot be controlled accurately by the handle,
this is obtained by a change in position of the endoscopic tube, the
object being so centered that it is grasped without side motion of the
forceps. When necessary, the distal end of the forceps may be pushed
laterally by the manipulation of the bronchoscope.

[FIG. 72.--A simple manikin. The weight of the small vise serves to
steady the rubber tubing. By the use of tubing of the size of the
invaded bronchus and a duplicate of the foreign body, any mechanical
problem can he simulated for solution or for practice, study of all
possible presentations, etc.]

_Practice on the Dog_.--Having mastered the technic of introduction on
the cadaver and trained the eye and fingers by practice work on the
rubber tube, experience should be had in the living lower air and food
passages with their pulsatory, respiratory, bechic and deglutitory
movements, and ever-present secretions. It is not only inhuman but
impossible to obtain this experience on children. Fortunately the dog
offers a most ready subject and need in no way be harmed nor pained by
this invaluable and life-saving practice. A small dog the size of a
terrier (say 6 to 10 pounds in weight) should be chosen and
anesthetized by the hypodermic injection of morphin sulphate in dosage
of approximately one-sixth of a grain per pound of body weight, given
about 45 minutes before the time of practice. Dogs stand large doses
of morphin without apparent ill effect, so that repeated injection may
be given in smaller dosage until the desired degree of relaxation
results. The first effect is vomiting which gives an empty sto