HYPOCHONDRIACAL INSANITY differs only in degree from hypochondriasis, described on a subsequent page. It is an incurable manifestation of one type of the mental degenerations. It is slowly progressive, and often ends in dementia. It differs from hypochondriacal melancholia in being an evolution of mental defect or degeneration, and in the fact that the mental depression, which is usually of a mild, periodic, or impulsive form, is secondary to the other symptoms, and not, as in hypochondriacal melancholia, the mental condition out of which the hypochondriacal symptoms are evolved. The TREATMENT consists in attention to the general laws of health, occupation, and a fattening diet. It is seldom successfully managed without occasional recourse to an asylum at least, and oftenest a permanent residence in hospitals, occasionally changing, is quite necessary. PERIODIC INSANITY, usually mania or melancholia, is marked by attacks recurring at more or less regular intervals, with a partial but not complete return to the previous mental health between them. It is one of the incurable degenerative mental diseases. The seeming recovery is only apparent, and the mental deterioration is progressive, although quite slow. The form of insanity is also not seldom a folie raisonnante (affective {151} or moral insanity) with periods of all sorts of excesses, destructive tendencies, tramp-life, destructive acts, drunkenness, stealing, indecent exposure, etc. In the intervals, which may be short or long, and which sometimes correspond to certain seasons of the year, the mental condition is still a pathological one, with the usual signs of mental degeneration, thereby being differentiated from recurrent insanity, one of the curable psychoneuroses, in which there is a state of mental health between the successive attacks, but no sort of regularity or periodicity in the recurrences. The prognosis is unfavorable, except in so far as a quiet life in an asylum tends to prolong the intervals between the periodic outbreaks, as well as to prevent annoyance to the community during them.