Changes in the nutrition of the tissues may be produced by suggestion. These effects lead into therapeutics—a subject which I do not propose to treat of here. But I may say that there seems no reasonable ground for doubting that in certain chosen subjects the suggestion of a congestion, a burn, a blister, a raised papule, or a bleeding from the nose or skin, may produce the effect. Messrs. Beaunis, Berjon, Bernheim, Bourru, Burot, Charcot, Delbœuf, Dumontpallier, Focachon, Forel, Jendrássik, Krafft-Ebing, Liébeault, Liégeois, Lipp, Mabille, and others have recently vouched for one or other of these effects. Messrs. Delbœuf and Liégeois have annulled by suggestion, one the effects of a burn, the other of a blister. Delbœuf was led to his experiments after seeing a burn on the skin produced by suggestion, at the Salpétrière, by reasoning that if the idea of a pain could produce inflammation it must be because pain was itself an inflammatory irritant, and that the abolition of it from a real burn ought therefore to entail the absence of inflammation. He applied the actual cautery (as well as vesicants) to symmetrical places on the skin, affirming that no pain should be felt on one of the sides. The result was a dry scorch on that side, with (as he assures me) no after-mark, but on the other side a regular blister with suppuration and a subsequent scar. This explains the innocuity of certain assaults made on subjects during trance. To test simulation, recourse is often had to sticking pins under their finger-nails or through their tongue, to inhalations of strong ammonia, and the like. These irritations, when not felt by the subject, seem to leave no after-consequences. One is reminded of the reported non-inflammatory character of the wounds made on themselves by dervishes in their pious orgies. On the other hand, the reddenings and bleedings of the skin along certain lines, suggested by tracing lines or pressing objects thereupon, put the accounts handed down to us of the stigmata of the cross appearing on the hands, feet, sides, and forehead of certain Catholic mystics in a new light. As so often happens, a fact is denied until a welcome interpretation comes with it. Then it is admitted readily enough; and evidence judged quite insufficient to back a claim, so long as the church had an interest in making it, proves to be quite sufficient for modern scientific enlightenment, the moment it appears that a reputed saint can thereby be classed as 'a case of hystero-epilepsy.'
There remain two other topics, viz., post-hypnotic effects of suggestion, and effects of suggestion in the waking state.
Post-hypnotic, or deferred, suggestions are such as are given to the patients during trance, to take effect after waking. They succeed with a certain number of patients even when the execution is named for a remote period—months or even a year, in one case reported by M. Liégeois. In this way one can make the patient feel a pain, or be paralyzed, or be hungry or thirsty, or have an hallucination, positive or negative, or perform some fantastic action after emerging from his trance. The effect in question may be ordered to take place not immediately, but after an interval of time has elapsed, and the interval may be left to the subject to measure, or may be marked by a certain signal. The moment the signal occurs, or the time is run out, the subject, who until then seems in a perfectly normal waking condition, will experience the suggested effect. In many instances, whilst thus obedient to the suggestion, he seems to fall into the hypnotic condition again. This is proved by the fact that the moment the hallucination or suggested performance is over he forgets it, denies all knowledge of it, and so forth; and by the further fact that he is 'suggestible' during its performance, that is, will receive new hallucinations, etc., at command. A moment later and this suggestibility has disappeared. It cannot be said, however, that relapse into the trance is an absolutely necessary condition for the post-hypnotic carrying out of commands, for the subject may be neither suggestible nor amnesic, and may struggle with all the strength of his will against the absurdity of this impulse which he feels rising in him, he knows not why. In these cases, as in most cases, he forgets the circumstance of the impulse having been suggested to him in a previous trance; regards it as arising within himself; and often improvises, as he yields to it, some more or less plausible or ingenious motive by which to justify it to the lookers-on. He acts, in short, with his usual sense of personal spontaneity and freedom; and the disbelievers in the freedom of the will have naturally made much of these cases in their attempts to show it to be an illusion.
The only really mysterious feature of these deferred suggestions is the patient's absolute ignorance during the interval preceding their execution that they have been deposited in his mind. They will often surge up at the preappointed time, even though you have vainly tried a while before to make him recall the circumstances of their production. The most important class of post-hypnotic suggestions are, of course, those relative to the patient's health—bowels, sleep, and other bodily functions. Among the most interesting (apart from the hallucinations) are those relative to future trances. One can determine the hour and minute, or the signal, at which the patient will of his own accord lapse into trance again. One can make him susceptible in future to another operator who may have been unsuccessful with him in the past. Or more important still in certain cases, one can, by suggesting that certain persons shall never be able hereafter to put him to sleep, remove him for all future time from hypnotic influences which might be dangerous. This, indeed, is the simple and natural safeguard against those 'dangers of hypnotism' of which uninstructed persons talk so vaguely. A subject who knows himself to be ultra-susceptible should never allow himself to be entranced by an operator in whose moral delicacy he lacks complete confidence; and he can use a trusted operator's suggestions to protect himself against liberties which others, knowing his weakness, might be tempted to take with him.
The mechanism by which the command is retained until the moment for its execution arrives is a mystery which has given rise to much discussion. The experiments of Gurney and the observations of M. Pierre Janet and others on certain hysterical somnabulists seem to prove that it is stored up in consciousness; not simply organically registered, but that the consciousness which thus retains it is split off, dissociated from the rest of the subject's mind. We have here, in short, an experimental production of one of those 'second' states of the personality of which we have spoken so often. Only here the second state coexists as well as alternates with the first. Gurney had the brilliant idea of tapping this second consciousness by means of the planchette. He found that certain persons, who were both hypnotic subjects and automatic writers, would if their hands were placed on a planchette (after being wakened from a trance in which they had received the suggestion of something to be done at a later time) write out unconsciously the order, or something connected with it. This shows that something inside of them, which could express itself through the hand alone, was continuing to think of the order, and possibly of it alone. These researches have opened a new vista of possible experimental investigations into the so-called 'second' states of the personality.
Some subjects seem almost as obedient to suggestion in the waking state as in sleep, or even more so, according to certain observers. Not only muscular phenomena, but changes of personality and hallucinations are recorded as the result of simple affirmation on the operator's part, without the previous ceremony of 'magnetizing' or putting into the 'mesmeric sleep.' These are all trained subjects, however, so far as I know, and the affirmation must apparently be accompanied by the patient concentrating his attention and gazing, however briefly, into the eyes of the operator. It is probable therefore that an extremely rapidly induced condition of trance is a prerequisite for success in these experiments.
I have now made mention of all the more important phenomena of the hypnotic trance. Of their therapeutic or forensic bearings this is not the proper place to speak. The recent literature of the subject is quite voluminous, but much of it consists in repetition. The best compendious work on the subject is 'Der Hypnotismus,' by Dr. A. Moll (Berlin, 1889; and just translated into English, N. Y., 1890), which is extraordinarily complete and judicious. The other writings most recommendable are subjoined in the note.[525] Most of them contain a historical sketch and much bibliography. A complete bibliography has been published by M. Dessoir (Berlin, 1888).