The Encyclopaedia Britannica defines diagnosis as "the process of identifying the disease by consideration of the history, symptoms, physical signs and examination in every way of the patient." All these factors are important and essential in making a correct diagnosis. In otolaryngology perhaps more reliance is placed on physical signs that are visual than in most other fields of medicine. In the majority of instances the final interpretation of the clinical picture depends on what is seen in the ear, nose, pharynx or larynx. The habit of wearing the head-mirror throughout working hours, so commonplace among otolaryngologists, is an unconscious acknowledgment of the importance of visual examination in this field.
In 1931, in a paper read before this section, I1 tried to bring out the importance of visual control by direct inspection in performing an adenoidectomy. In a large series of cases in which operations had been previously performed