Infections of the middle ear give rise to pain, fever, general malaise and various degrees of temporary deafness. The destructive processes of bacteria produce necrosis of bony and soft tissues, and the repair is marked by deposits of fibrous tissue. The possibility that toxins in the middle ear effect changes in the endings of the auditory and vestibular nerves has been given little consideration. It has been shown1 that procaine hydrochloride, quinine, alcohol and hydrochloric acid are capable of passing from the middle ear to the endings of the vestibular nerve and there producing functional changes. It is probable that bacterial toxins in the middle ear would penetrate also to the endings of the eighth nerve. It is possible that the toxins of certain bacteria are capable of destroying the function of endings of this same nerve. Therefore, it was decided to make observations on the effects