This article describes the case of Mary Barnes, who was 12 years old in 1894. After an illness Mary began to develop multiple personalities over a number of years. 10 distinct personalities were noted. Their appearance lasted anywhere from a number of weeks without interruption to a mere matter of minutes, never to return. Each of the personalities was distinct and would be accompanied with facial features, body abilities and knowledge. One personality was a deaf mute, one was blind, and one was paralyzed, several personalities had low intelligence levels. Dr. Wilson describes each of the personalities in detail, along with their arrival and departure dates. The author gives a brief overview of the Nervous System. Letters written by Mary’s different personalities are also included.
Dr. Albert Wilson documents his experiences as the primary physician of an adolescent girl who, over the course of four years, displayed more than a dozen distinct identities. Each persona was unique in its memories, mental capabilities, physical disturbances, aesthetic abilities and moral development. The first secondary personality appeared while the girl suffered from an "attack of meningitis." The physician hypothesizes that vaso-motor changes in the brain may play a central role in the etiology of this case of double consciousness. Finally, while considering the violent and socially deviant nature of some of the patient's personalities, Wilson examines moral and legal responsibility as it relates to the acts committed by individuals with dissociated identities.