[120] _Cadaver Practice_.--The fundamental principles of peroral endoscopy are best taught on the cadaver. It is necessary that a specially prepared subject be had, in order to obtain the required degree of flexibility. Injecting fluid of the following formula worked out by Prof. J. Parsons Schaeffer for the Bronchoscopic Clinic courses, has proved very satisfactory: Sodium carbonate--1 1/2 lbs. White arsenic--2 1/2 lbs. Potassium nitrate--3 lbs. Water--5 gal. Boil until arsenic is dissolved. When cold add: Carbolic acid 1500 c.c. Glycerin 1250 c.c. Alcohol (95%) 1250 c.c. For each body use about 3 gal. of fluid. The method of introduction of the endoscopic tube, and its various positions can be demonstrated and repeatedly practiced on the cadaver until a perfected technic is developed in both the operator and assistant who holds the head, and the one who passes the instruments to the operator. In no other manner can the landmarks and endoscopic anatomy be studied so thoroughly and practically, and in no other way can the pupil be taught to avoid killing his patient. The danger-points in esophagoscopy are not demonstrable on the living without actually incurring mortality. Laryngeal growths may be simulated, foreign body problems created and their mechanical difficulties solved and practice work with the forceps and tube perfected. _Practice on the Rubber-tube Manikin_.--This must be carried out in two ways. 1. General practice with all sorts of objects for the education of the eye and the fingers. 2. Before undertaking a foreign body case, practice should be had with a duplicate of the foreign body.