get into the most dangerous situations without experiencing terror. But the explanation of this ought not to be attended with any real difficulty; for we must reflect, that alarm cannot be felt unless we apprehend danger, and that the latter, however great it may be, cannot excite emotion of any kind, so long as we are ignorant of its existence. This is the situation in which sleep-walkers, in a great majority of cases, stand. The reasoning faculties, which point out the existence of danger, are generally in a state of complete slumber, and unable to produce corresponding emotions in the mind. And even if danger should be perceived by a sleep-walker and avoided, as is sometimes the case, his want of terror is to be imputed to a quiescent state of the organ of Cautiousness; the sense of fear originating in high excitement of this particular part of the brain. That the reasoning faculties, however, are sometimes only very partially suspended we have abundant evidence, in the fact of the individual not only, now and then, studiously avoiding danger, but performing offices which require no small degree of judgment. In the higher kinds of somnambulism, so many of the organs of the brain are in activity, and there is such perfect wakefulness of the external senses and locomotive powers, that the person may almost be said to be awake."
"The remote causes of sleep-walking," he again remarks, "are so obscure, that it is seldom we are able to ascertain them. General irritability of frame, a nervous temperament, and bad digestion, will dispose to the affection. Being a modification of dreaming, those who are much troubled with the latter will, consequently, be most prone to its attacks. The causes, however, are, in a great majority of cases, so completely unknown, that any attempt to investigate them would be fruitless; and we are compelled to refer the complaint to some idiosyncracy of constitution beyond the reach of human knowledge."
"To prevent a recurrence of somnambulism," he adds, "we should remove, if possible, the cause which gave rise to it. Thus, if it proceed from a disordered state of the stomach, or biliary system, we must employ the various medicines used in such cases. Plenty of exercise should be taken, and late hours and much study avoided. If it arises from plethora, he must be blooded, and live low; should hysteria produce it, anti-spasmodics, such as valerian, ammonia, assafœtida, and opium may be necessary.
"But, unfortunately, we can often refer sleep-walking to no complaint whatever. In this case, all that can be done is to carry the individual as safely as possible through the paroxysm, and prevent him from injury
