In 1887 Korsakoff described polyneuritic psychosis as a special morbid entity, particularly characterised by amnesic disorders. Another name which he gave to this condition was toxæmic (psychical) cerebropathy. He recognised two varieties—one slight, characterised by amnesia affecting recent events; another severe, with marked amnesia accompanied by false reminiscences and delusions. This view has since been severely criticised by Babinski, Chaslin, Séglas, Ballet, etc., who maintain that practically this psychosis of Korsakoff is only a form of mental confusion, and in the two conditions one finds identical amnesic disorders.