Within recent years we have experienced a marked advance in our knowledge of tuberculous disease. We are now in a position to consider its varied phases from a scientific standpoint and to recognize its influence in the course of other maladies the pathology of which may be less obvious. Its relation to mental disease has engaged the physician's special attention for many years, and even prior to the organization of psychological medicine the intimate association which is now acknowledged to exist between tuberculosis and insanity was well known to contemporary writers. It has, however, been reserved to recent authors to classify the symptoms and signs which may guide us with tolerable accuracy to diagnose a case of phthisical insanity by the character of the mental disease coming under our observation.