Having observed a patient in otherwise perfect health, who presented, without tangible cause, a discharge of cerebrospinal fluid from one side of the nose, for two and a half years intermittently, but for three years continuously, St. Clair Thomson1 was led to undertake a study of the literature of the subject, with the result of collecting the records of twenty other cases. The patient was an unmarried woman, 25 years old, and she suffered only from the mechanical inconvenience of the discharge from the nose. Careful bacteriologic examination of the fluid proved it to be sterile, and chemical study demonstrated it to be cerebrospinal fluid. The discharge ceased on four occasions without obvious cause, and without the development of any other symptom— once for a month, at another time for two months, and a third time for a month, and again for sixteen days. All treatment was unavailing.