It will not be amiss to review cursorily the pathology of inflammation in general and then to consider it as it obtains in the practice of otology. The four cardinal symptoms of inflammation, known since the time of Galen, are calor, rubor, dolor and tumor. To these is added a fifth, namely, lost or altered function. Calor, or increased heat in the inflammatory zone, is due to active hyperemia with its consequent increased metabolic rate. This is a constant objective sign in all acute inflammations. It may also be a subjective symptom, for the patient may appreciate increased heat in the part, but more often it is indistinguishable from the sensation of pain. This can be ascertained in accessible regions, by the examiner touching the part or by means of a thermometer held between the affected area and the examiner's finger, and by the repetition of the process over normal