Concentration of mind upon intellectual or physical action is usually possible only in our waking and wakeful moments. Fatigue of brain renders us incapable of it: and in sleep, the natural consequence of such fatigued we generally lose consciousness, and only exercise those functions which are performed automatically. In dreams consciousness is once more aroused, and we may ever use some reasoning power, and be influenced from without through our senses. But in ordinary dreams there is no concentration of ideas upon an act to be performed 01 a goal to be reached. When a sleeper uses this effort of mind, he passes out of the region of dreams, and enter." that of somnambulism.

In somnambulism actions of extraordinary difficulty such as could not be performed by the sleeper during hi: waking hours - except, perhaps, through mind-concentra tion caused by some overpowering impulse or motive-are accomplished with perfect ease. Persons in this con dition will walk on the extreme edge of a precipice, climt dangerous heights, get out of a house through an upper story window. There are numerous instances of this on record, of which I will quote two or three. Dr. Paul Gamier * gives one of a patient, a dentist's assistant, of feeble bodily and mental health, who frequently fell into a state of somnambulism. On one of these occasions he escaped by a window from the ward of the Hotel Dieu, in which he was undergoing treatment, and, though a peculiarly unathletic person, walked easily and fearlessly along the sloping parapet of the facade - a feat which a trained gymnast could hardly have accomplished. He awoke in the course of this dangerous performance, and had to be rescued by means of a ladder. With the return of consciousness reason awoke, and he understood the horror of his position. While blindly obeying his impulse he had acted automatically, and fear, which is a product of reflection and association of ideas, † had no existence for him.

Nevertheless, it is a popular error to suppose that somnambulists are safeguarded from accident. Reference to the daily papers tells a different tale, and hardly a week passes without a serious or fatal accident happening to a sleep-walker. It is, therefore, a matter of congratulation that in hypnotism we possess an almost certain cure for this dangerous and embarrassing affection. A patient of my own, a young man twenty years of age, not an habitual somnambulist, but a sufferer from nightmare produced by chronic dyspepsia, on one occasion, while spending the night in a hotel, dreamed that he was confined in a dungeon from which he must escape. The dream, no doubt, passed into somnambulism, for under its influence he broke his iron bedstead - a feat of strength which, waking, he assuredly could not have accomplished - and tore up his bedclothes. His amazement was great when he awoke in the morning amid the ruins of his own creation. He remembered his dream, but had no recollection whatever of the acts into which he had been led by it.

The case of Dr. Haydn Brown's referred to on p. 209 is a good example of nocturnal mania of a more serious type.

* ' Somnambulisme devant les Tribuneaux,' Paris, 1888. † Infants, in whom, of course, neither is possible, will, if allowed, grasp at the flame of a candle, or a sharp instrument; and young-children will fearlessly put themselves into positions of great danger.

Dr. Bevan Lewis refers to a case of habitual somnambulism with which he is acquainted. The subject, a medical man, is frequently called up at night to visit patients. He gets up and dresses automatically, but is quite unconscious of his actions and of his destination until he is a considerable distance from his house (' Text-Book of Mental Diseases,' p. 150).

The hypnotic state, which stops short of loss of consciousness, has been aptly compared to that condition between sleeping and waking which is characterized by inertia of mind and body, and by the greater or less abeyance of spontaneity. There is another similarity between the dream state and hypnosis. There are many cases on record, and most medical men must have met with instances in practice, where the morbid condition either took its rise from, or was coincident with, a terrifying or painful dream. Hysterical paralysis not uncommonly commences in this way, and it is probable that certain neurotic troubles take their form from the influence of dream-suggestion. In incipient insanity the delusions which subsequently become permanent and rampant are often at first only experienced either in dreams or in the moments of incomplete wakefulness, and their occurrence is due either to morbid auto-suggestion or to the influence of morbid conditions on the mind in the sleeping state which in waking moments are either not noticed or are corrected by the intelligence.

It seems possible for healthy suggestion to combat and conquer many of the conditions which are thus ushered in.

Some years ago I attended a case in point. The patient, a lady 0 thirty, had always been neurotic, and had suffered from indifferent health. She was, however, able to get through life fairly well until, ir September, 1890, she went to stay away from home. In the evening the assembled company set themselves to tell the most blood-curdling stories they could think of, with the result that Miss X------retired to her room in a state of terror, and with unstrung nerves. She had to sleep alone, a thing she was unaccustomed to, and this added to her alarm. In the middle of the night the house was aroused by screams proceeding from her room, and when an entrance was made Miss X------ was found in an attack of violent hysteria. When she recovered from the fit she was only able to remember that she had had a terrifying dream embodying the stories she had heard. From that time her health completely gave way; she started at the least sound, ingestion of food was always followed by vomiting, and obstinate insomnia supervened. She underwent a six weeks' course of Weir-Mitchell treatment, from which she derived no benefit, and then, after a further three months of misery, expressed her wish to try hypnotism.

She was not an easy subject, as her mind was in such a condition that it was almost impossible to fix her attention, and at first, whenever she felt going off, she could not help pulling herself up with a start. However, perseverance prevailed, and from the moment she was slightly influenced she began to improve. She was restored, after two months' treatment, to about the same state of health she was in before the attack.