Epilepsy, in certain of its obscurer forms, is responsible for many conditions in which there is a sudden access of insane excitement of a violent, often very impulsive, character, though sometimes of very short duration. During this state the patient is practically irresponsible, and yet he may have sufficient control over his actions to enable him to work serious harm. Such a stage of excitement may last not more than an hour or two; usually all trace of it passes off in a day or two; before and after it the patient may be in perfectly sound sense and in apparently good health. One of our best authorities here in America, Berkley, in his treatise on _Mental Diseases_, gives the following striking opinion on this subject. "The subject of masked epilepsy and the consequent mania is replete with interest to the physician and the jurist, since such patients are prone to impulsive acts of violence and automatic states in which the most complicated, but entirely unconscious, actions and crimes may be carried out without premeditation on the part of the sufferer, being also out of all accord with his character during his intervals of mental health. Besides the irritability, impulsiveness is an equally characteristic feature. No form of insanity more frequently gives rise to assaults and murder than epilepsy, and in no form of alienation is the physician so frequently called to the witness stand to determine the responsibility of the criminal." One of the most prominent features of all epilepsy is the well known tendency to irritability that characterises sufferers from the disease. This of itself is an index of the fact that {254} their responsibility is somewhat lessened, since they are unable to withstand even the petty annoyances of life without exaggerated reaction. Friends of epileptics know very well that it is a preliminary symptom of the coming on of an attack of epilepsy for the patients to become even more irritable than usual. Just after the comatose condition which follows an attack of epilepsy patients are also prone to be very irritable. An attack of epilepsy is really an explosion of nerve force, for no rational purpose, along motor nerves. This same tendency to an unwarranted explosion of energy is liable to occur along other nerve tracts that rule the patient's disposition.