Methods for the study of electrical discharges of the brain and of the retina have been developed to such a degree that they are applied as clinical tests. Electrical discharges from the vestibular nerve have been studied in animals in which the electrodes were inserted into the inner ear or placed directly on parts of its nervous apparatus. Spiegel, Wycis, and Umlauf8 attempted in man to record the electrolabyrinthogram from parts of the external ear, particularly by meatal-retromastoid electrodes. In patients with unilateral eighth nerve tumors these authors compared the effects of rotation upon the normal and upon the affected side. At least in some instances, they found a postrotatory increase of the amplitude of the discharges on the side of the intact labyrinth or intact eighth nerve, as compared with the side of the tumor.
In the course of these studies it became evident that it would be