The physical symptoms of insanity are perverted sensations of almost every conceivable kind, resulting in depraved instincts and acts, psycho-motor excitability, convulsive action, choreic movements, uncontrollable muscular agitation (springing, shouting, swearing, dancing, running, destructive tendencies, etc.), elevation or depression of pulse, respiration, or temperature, loss of appetite, digestive disturbances, pain, fever, tetanic and cataleptic rigidity, paralysis, tremor, ataxia, epileptic seizures, convulsions, muscular contractions, increased or decreased secretions and excretions, disturbances of general nutrition. The course of the various mental diseases is to a great extent chronic, some forms being incurable from the beginning, others curable to such {121} an extent that of recent cases from one-half to nine-tenths recover, of whom a considerable proportion remain well to their death. The duration of the mental diseases is from a few days to a lifetime, sometimes not even shortening life. The termination is oftenest in incurable chronicity or dementia, less often in permanent recovery without recurrence, and still less often in death from the first attack. Unfortunately, the essentially incurable and the curable forms of mental disease are classed together in statistics of insanity. While many types are absolutely fatal or certain to end in hopeless chronicity or dementia, others tend to recovery. In some forms relapses and recurrent attacks are to be expected: in others they seldom occur. In many cases there is no more probability of transmission to children than in Bright's disease, and no more likelihood of subsequent attacks than in typhoid fever. MORBID ANATOMY AND PATHOLOGY.—It is thought by the best observers that insanity depends upon a functional brain disturbance, or at least upon a disordered condition which it is beyond our present power to discover, and that the normal working of the mind depends upon a brain healthy to such an extent that its millions of functional activities, in their endless relations to each other, preserve a state of equilibrium; or, in other words, that the higher centres maintain their power of control over the lower. It is doubtless true that this relation depends in general upon a healthy brain, but it is not yet known to what extent. Disease of the brain or its membranes, apparently slight, often seems to cause insanity, and often there is marked disease without insanity. We certainly cannot place all the pathological conditions found in the brain of a person dying insane in direct causal relation to his insanity. The anæmia observed by Meynert in melancholia and the hyperæmia of maniacal excitement, even if proved to be universal in those conditions, may be only symptoms of the underlying disease or caused by it. It is certain that there are indications of as great anæmia or hyperæmia in other states without insanity.