It would be easy to bring forward other instances of which I am perfectly cognizant, or which have been cited by authors in illustration of the point in question, but it is scarcely necessary to enlarge further upon this portion of the subject. We should be careful, however, not to mistake the effect for the cause, an error which is often committed in this as well as in other matters. It is well known that many cases of insanity are marked in the early stages by persistent insomnia. Doubtless this is frequently a consequence of the morbid action already set up in the brain; but much observation has satisfied me that it is more often the cause of the cerebral aberration, and that by proper medical treatment the mental excitement may be generally allayed. Certainly the means most commonly resorted to in such instances are adopted without the full consideration so imperatively necessary, and consequently are fully as liable to increase as to lessen the disturbance. We cannot employ too much care in doing everything in our power to prevent the occurrence of those slight attacks of cerebral congestion, which, though perhaps scarcely observable at the time, are yet fraught with very serious consequences. Persons have had their whole characters changed by an apparently trifling interference with the circulation of blood in the head. A person of my acquaintance was naturally of good disposition, amiable in his character, and considerate in his dealings with others; but after an attack of vertigo, attended with unconsciousness of but a few moments’ duration, his whole mental organization underwent a radical change. He became deceitful, morose, and exceedingly overbearing and tyrannical toward all with whom he came in contact, and whom it was safe for him to maltreat. Tuke and Bucknill[127] refer to the case of a lady whose character had always been distinguished for conscientiousness, whose religious education had been of a somber kind, and who, suffering under an attack of small-pox attended with congestion of the brain, recovered, with the natural bent of her disposition greatly exaggerated. The irritability of conscience had become an actual disease, destroying the happiness of the individual and rendering her incompetent to discharge any of the duties of life. The same authors also mention the instance of a distinguished admiral who had always been remarkable for pride and liability to passionate anger, becoming the subject of cerebral excitement, loss of sleep, and general feverishness consequent upon the chagrin caused by a supposed neglect by the government.