1. Direct examination of the external meatus after drying with cotton applicator usually determines the location and extent of perforation of the drum and the general nature of the discharge, whether purulent or mucopurulent. Very rarely one finds a serious discharge which means a very slight infection or discharge from non-infective inflammation. The presence of whitish or greyish pus, mucoid and stringy, usually means pneumococcus infection. Greyish, purulent non-mucoid discharge usually indicates streptococcus or bacillus influenzæ infection. Yellow, purulent discharge suggests staphylococcus infection. The general appearance of the discharge, however, cannot be considered of important diagnostic value because most chronic suppurations are mixed infections, because of long exposure to external contamination. 2. After cleaning the meatus, several smears should be made directly from the opening in the drum. By staining with methylin blue or gentian violet, the nature of the bacterial infection can be determined and this is very important. By staining another smear with hematoxylin and washing in water, any dark irregular particles, bone debris, may be found, which means bone disintegration. This too, is very important. 3. Transillumination is sometimes of value. The mastoid may be transilluminated by placing a good rubber covered transilluminating lamp over the mastoid and observing the external meatus through an aural speculum. If the mastoid is free from infection the light will pass through and illuminate the meatus. 4. The X-ray plate is, of course, the best means of determining the nature and extent of mastoid involvement. =Treatment.=—This is certainly one of the most difficult diseases of the ear that one is ever called upon to treat and the physician should be cautioned against offering a favorable prognosis. Perhaps the most difficult thing about its treatment that the doctor has to learn is that practically none of the so-called antiseptic washes do any good, but on the other hand they often do harm. Certain general principles are important and the treatment must depend upon the nature and extent of the infection and pathology present in each case. The constitutional treatment consists of everything that will increase the patient’s general resistance and certainly all lesions of the cervical, upper dorsal and mandibles must be properly adjusted, but this is not enough. All spinal lesions that may exert an influence on metabolism and elimination are of important consideration. The diet, habits and environment of the patient must be considered. A careful examination of the nasopharyngeal tract may reveal some other focal infection, such as chronic tonsillitis, pharyngitis or sinuitis, which is maintaining the infection through the Eustachian tube. There may be a focal or general infection of some other part of the body, which is reducing resistance or causing a hematogenous infection of the tympanic cavity or mastoid cells.