The _prognosis_, or means of ascertaining the probable event of mental derangement, is founded on the consideration of many different circumstances, such as the particular modification of the malady; the violence of the symptoms; the duration and frequency of the attack; its causes; the age, sex, constitutional temperament, and hereditary dispositions of the affected individual; the general state of his health; and the particular nature of his bodily maladies; upon each of which we shall offer a few observations.[536] It has been remarked that those affected with furious mania recover in a larger proportion than those who suffer under the depressing influence of melancholy, but that when the maniacal and melancholic states alternate, the hope of recovery is farther diminished. The probability of cure is also more or less, according to the duration of the disease; when, however, it has acquired a systematic character, it becomes very difficult to remove it, so that after it has continued upwards of a year, patients at public asylums, as in Bethlem and Saint Luke’s, are pronounced incurable, and treated accordingly. In considering the causes of mania, we must class them in two divisions—_Predisposing_, and _Exciting_. Among the former of these causes stand _hereditary predisposition_; _injuries of the brain_; (these also belong to the class of exciting causes); _certain bodily diseases_; and a _peculiar temperament_. Among the latter we may first enumerate those of a PHYSICAL nature, as _frequent intoxication_; _fever_; _mercurial medicines_, largely administered; _the suppression of periodical or occasional discharges and secretions_; _parturition_; _injuries to the head from external violence_, _&c._ The MORAL causes include those emotions which are conceived to originate from the mind itself, and which, from their excess, tend to distort the natural feelings; or, from their repeated accessions, and unrestrained indulgence, at length overthrow the barriers of reason and established opinion; such are the _gusts of violent passion_, and the _protracted indulgence of grief_; the _terror_ impressed by erroneous views of religion; the _degradation of pride_; _disappointment in love_; and _sudden fright_.