Originally used to describe any case of dementia with chronic excitement, the term “chronic mania” has been limited in its application to a group of cases described by Schott and others during this century. In the main, they apply it to cases of mania developed after the age of 40, and differing from an acute attack chiefly in their long duration. In the cases I describe I have confined myself to this usage, and have not included constitutional fluctuating hypomanics who have manifested this after their youth onwards, nor do I include prolonged manic phases in circular manic-depressive cases.