It cannot be doubted that the exercises and suggestions employed to induce movements in cases of muscular dystrophy may prove extremely exhausting.

Instead of supposing hypnosis to be a cause of permanent attacks of hysterical convulsions, we are far more justified in assuming that when once a complete hypnosis has been obtained we have in our hands a trustworthy means of permanently lessening the convulsions. In reality, an attack of hysteria is not nearly so important as some would have us believe; and we certainly know that hysterical attacks are sometimes artificially induced during lectures for purposes of demonstration.

I am satisfied from certain cases of my own, that hysterical attacks do not indicate the necessity of stopping the hypnotic treatment. This agrees with the experience of Sperling, Krakauer and others, who have also had cases in which, though there were attacks at first, yet cures were subsequently obtained. These cases also show that the attacks are by no means permanently increased in number, even when they take place at the first or second attempt to hypnotize. The old mesmerists - e.g., Noizet, Puysegur, Mesmer, Deslon - were well acquainted with these convulsions, which they called crises, and even thought them a favourable sign, which was certainly a mistake. A man who is so very much afraid of being confronted with an attack of hysteria should make it a principle never to attempt to hypnotize a patient who is either excited or afraid of hypnosis. We shall see later on that dread of hypnosis does not contra-indicate its use. It is also said that mental disorders, and even morbid delusions, may result from hypnosis.

When any one who has frequently been hypnotized becomes the victim of delusions, we must be on our guard not to assume any causal connection too hastily, especially if a long interval has elapsed since the hypnosis was practised. People without expert knowledge may be misled on the question of causal connection by the nature of a delusion. It is well known that delusions are influenced by the ideas prevalent at the time; it is therefore not surprising that in recent years we have frequently met with the delusion of being magnetized or hypnotized. When this delusion occurs in a person who has been hypnotized at some time or other, it does not necessarily follow that the hypnosis has had even the slightest injurious effect on him. The most we can assume is that the nature of the delusion, which would otherwise have appeared in some other form, was in some way determined by the hypnotic experiments on the subject. Delusions of thought-transference effected by persons at a distance occur in a similar way.

Of course we should never think of denying the possibility of mental disorders being caused by the unscientific use of hypnotism; such cases have repeatedly been reported, especially after some public hypnotizer has made his appearance - for example, by Finkelnberg in connection with Hansen's public experiments, by Lombroso in connection with Donato's; also by Weinbaum, Schmitz, and others. And we must not overlook the fact that the enormous excitement that prevails at such exhibitions and its emotional effects are liable to cause at least temporary mental aberration in persons who are that way predisposed. There is also a certain amount of connection between hypnosis and those forms of mental derangement which follow spiritualistic stances. A state of trance - i.e. an auto-hypnosis - is often caused by such seances; and as Charcot, Gilles de la Tourette, and Henneberg have shown, such intense excitement may occasionally lead to mental disorder in persons of a highly emotional disposition.

It has been mentioned by some as a further danger of hypnosis - Sioli, for instance - that after repeated hypnotism an inordinate desire for its repetition may be set up. Rechtsamer, of St. Petersburg, reports that a lady who had undergone hypnotic treatment subsequently made one of her friends continue hypnotizing her, because it was so pleasing. Such a result of hypnosis can be avoided by taking proper precautions, but especially by making counter-suggestions.

I may here mention some slight ailments which are occasionally found after hypnosis, especially in cases of hysteria. They are often the result of a bad method or of auto-suggestion, and occur after both deep and light hypnoses. The chief symptoms are fatigue, heaviness of the limbs, drowsiness, and faintness. In some cases it is very difficult to combat these symptoms when there is great hysterical auto-suggestibility, and it may even be necessary to discontinue the hypnotic treatment. In most cases we can prevent these auto-suggestions by employing the proper technique, but as a rule this is only possible if we suggest from the beginning - i.e., at the first experiment - that any feeling of fatigue or sleepiness will disappear after waking. It is often advantageous to get rid of the fatigue before the awakening. There is no necessity to overrate these attendant phenomena of hypnosis, even if they are unpleasant, and certainly no one will do so who remembers that suggestion is often responsible for temporary after-effects in the case of other remedies, especially where there is hysteria.

Although the dangers of hypnotism which we have hitherto described are of no great practical importance, there are others that are much more serious in that respect. I mean the increased tendency to hypnosis which includes a greater liability to auto-hypnosis, and the heightened susceptibility to suggestion in the waking state. Mobius maintains, that apart from a wilful craving for hypnosis, the danger of involuntary hypnosis is quite the only danger from hypnotic treatment that need be considered. Cases have been described in which spontaneous hypnosis has occurred a short time after a subject has been hypnotized injudiciously, and even all the events of the previous hypnosis have been reproduced by auto-suggestion. Bremaud has described one such case, and Solow another. But the cases in which, as I suspect, unscrupulous hypnotizers sometimes induce such hypnoses intentionally are far more serious, for subjects become filled with a feeling of complete dependence on the hypnotizer, are in constant dread of falling under his influence, and even when no real form of insanity is developed they lose all freedom of action and feeling of independence.