The principles consist in a careful investigation of each epileptic case and treatment, not general, but individual. Dr. Erlenmeyer makes the complaint, probably with justice, that cases of epilepsy are far too frequently treated in a rule-of-thumb manner, and scarcely at all investigated. He then proceeds to describe how a case should be examined (the details are somewhat alarming, it must be confessed), and subsequently describes the many varieties of epilepsy, including Jacksonian. On p. 13 we find one cause given which sounds theoretical, “commotio cerebri.” In the investigation of causes he insists that the history should be most carefully taken; and under the head of injury should include even a simple box on the ear! We would suggest that so careful a history will scarcely ever fail to discover some cause, right or wrong. A case of epilepsy cured by trepanning, which operation was done at the author's insistence, is included in the text of some remarks at the end of the brochure.