One of the most important and effective methods of hypnotic treatment is by post-hypnotic suggestion. They are deferred suggestions given to the subjects during hypnosis, to take effect after waking. The patient is hypnotised, and then impressions are made upon him which reappear when he is awake. The deeper the hypnosis the greater the success of posthypnotic suggestion. When he is recalled to consciousness he has no recollection of having received any instruction, hut at the time stated or when the circumstances arise he will proceed to do what has been suggested to him.

When subjects are questioned as to their motive for acting on a post-hypnotic suggestion, they give different answers: they either believe that they have so acted of their own accord, and invent plausible and ingenious reasons for their proceedings, or they say they felt impelled to act so. "It came into my head to do it," is a common reply. We can use suggestion here also. When the original suggestion is being made, it may at the same time be suggested to the subject to believe that he has acted of his own free will.

Something also depends upon the frequency with which the experiment is made, and particularly on the greater or lesser absurdity of the suggested act. If a suggestion is absurd, the subject may struggle against the impulse which he feels rising in him—he knows not why. For example, I told a lady who consulted me for neuralgic pains, while in the hypnotic state, that she would write to me the same evening after dinner whether her neuralgia had disappeared; hut I got no letter next morning. On enquiring the reason, her cousin, who accompanied her, told me that the patient, after dinner, went to her writing-desk as if to write a note, but turned round again with the remark: "I thought of writing to the doctor to tell him that my neuralgia has gone, but there is no sense in doing so, for he could not get my letter until to-morrow, when I shall see him in any case, and can tell him then."

Sometimes, if the hypnosis is slight, there is some suspicion of a post-hypnotic suggestion, though no actual recollection, as in the following example. A lady suffering from a spinal complaint was getting better, but mentioned to me that she slept badly. When hypnotised I asked her what time she usually went to bed, and on hearing it was 10:30 I suggested that she would get very drowsy then and fall asleep, sleeping well till her usual time of getting up. During the same day, however, she felt so well that she decided to go with her companion to the Lyceum theatre, to see Sherlock Holmes performed. Although this is an exciting drama, and interested the lady immensely, her companion related to me that suddenly she found her asleep on her seat, and had to wake her. On being roused, the patient apologised and remarked: "It is very curious. I suppose the doctor this morning must have suggested I should go to sleep at this hour!"

It appears wonderful to most people that an event should take place at whatever time we may have suggested to the subject while in the trance, whether in 1, 2, or 24 hours, or 1,000 or 2,000 minutes, or in a month or more remote periods from the day on which a subject has been hypnotised.

Milne Bramwell has performed many successful experiments that way, as, for example, the following: A woman was told that in so many thousand minutes she is to write her name, the hour of the day, and the date. She was not very well educated, and therefore was not likely to work out the number of hours and minutes successfully; and yet, at the time appointed, she wrote down her name and put the date and hour, and was surprised to find what she had done.

In another case, he told a young lady, aged nineteen, to make the sign of the cross after the lapse of 4,335 minutes. In spite of the fact that she had forgotten all about the suggestion she fulfilled it accurately.

The late Professor Delboeuf, of Liege, also made some interesting experiments on the computation of time by somnambules.

There are numerous cases on record in which a subject has been ordered to go to a certain person's house, at a certain time, and deliver some message. As the time approaches he is seen to be restless till he sets out for his destination. He pays no attention to the people he may meet, and if they purposely arrest him, he forces his way onwards, delivers his message, and can only say that he felt he had to do so.

The sense of time appears to be an innate mental power, for there have been cases of idiot-boys who were able to guess the time correctly, no matter how suddenly the question was put to them.

It would appear that our subconsciousness is marking time very accurately, without our being aware of it, and at the suggested moment an impulse arises which arouses our consciousness. Even when we are not hypnotised, but suggest to ourselves certain acts to take place at a particular time, the event will happen at the time indicated. Many people on going to bed can "will" to awake at a certain hour.

When the mind is made up to perform a certain action at a certain time, the idea is then dismissed from the mind; but if the subconsciousness has been properly trained, at the definite time, or reasonably near it, the action will be performed, although neither the thought of the time nor the idea of performing the action may have been in the mind from the moment that the resolution was taken and was put on one side to make room for other ideas.

Sometimes, no definite time is given, but we suggest that at a time marked by a signal a certain event is to take place. The moment the signal occurs the subject, who until then seems in a perfectly normal waking condition, will experience the effect of the suggested event.

In the same manner, one can determine the hour and minute, by the signal, at which the patient will of his own accord lapse into trance again.

But, what is more important still, one can prevent by post-hypnotic suggestion any other person being able to hypnotise the patient, and one can even suggest a resisting power against one's own influence. Often, when I have cured a person and there was no likelihood of their requiring my services any more, I have suggested to them, in the last trance, that no one, not even myself, shall ever be able to hypnotise them again. In such cases, I have tried during the same week whether I could hypnotise them once more, but failed. "Whether I should have failed equally after a year or so, I am not in a position to tell, not having had occasion to test again.

Anyhow, this de-hypnotisation of a patient is an excellent precaution for susceptible people against unexpected hypnosis by designing persons who know their susceptibility, and that is what most people are afraid of.

I have already given examples of negative hallucinations in the post-hypnotic state in the previous chapter. Here is another of interest. It was suggested to a subject that on waking he would notice that his brother, who was present, who had always worn a moustache, had shaved it off; and, indeed, on waking the moustache was absolutely invisible to him, and he was not able to feel it either. This post-hypnotic hallucination and anassthesia to the touch is a highly-interesting phenomenon, and the perplexity of the subject on waking was truly pathetic. After conversing with his brother, he suddenly noticed him clean-shaven, and remonstrated with him for having spoiled his appearance. But the moment the operator said, "It is all right; don't you see the moustache is there?" it became visible to him.

Of course, suggestions that may excite ridicule should be avoided, even on subjects who volunteer for the experiment, and I need hardly insist that patients are not to he used for such purposes.

Experimentation and clinical observation have conclusively proved that a complex of ideas formed in hypnosis, whether remembered when the personality is awake or not, can affect, modify, or determine the ideas, beliefs, feelings, emotions, etc., of the individual. The elements of the hypnotic complex enter the stream of thought of everyday life and modify it.

The most important of all post-hypnotic suggestions are, of course, those relative to the patient's health. In this way one can make the patient who is melancholic feel happy, the patient who has no appetite feel hungry, or the man who has morbid habits have hallucinations which will deter him from indulging in them after emerging from his trance, without the patient being conscious that any suggestion has been made.

A person suffering from insomnia may be told in the hypnotic state that he will get drowsy at eleven o 'clock at night, and sleep soundly until eight in the morning, waking up quite fresh in body and mind. Another person addicted to the drink or drug habit may be told that when the temptation arises again it will be successfully conquered, that he will fear the consequences of such action, or other reasons (see chapters on "Treatment") may be suggested to arise in his mind, as if they were entirely his own, so that he has no remembrance or suspicion of their being suggested to him.

Even dreams can be influenced by post-hypnotic suggestion. I have told patients of a melancholic state of mind whilst in the trance most inspiring dreams suited to their character and ambitions in life, to be dreamt on the succeeding night, and told them that they would remember them on the following day, and feel happy in the enjoyment of the recollection. Thus I could influence their state of mind when no other remedy was successful. Indeed, let me remark here that success in curing patients by means of hypnosis depends not merely on knowing how to hypnotise, as some people and even professional men seem to believe, but still more on knowing how to make the right suggestions' individually, according to the mind and character, desires and habits of the patient. A knowledge of human nature is, therefore, essential.

Sometimes hysteria, as well as melancholy, is caused by some event of the past life, which the patient cannot forget, or which,, even if the remembrance no longer exists in his active consciousness, persists in subconsciousness. Is it not a blessing that in the trance the subconscious memory can also be influenced by posthypnotic suggestion, and a person can be made to forget on waking the painful events of his past life, that have had such baneful influence on his mind ?

The physiological effects produced in the hypnotic state can also be produced in the post-hypnotic state.

Hunger and thirst can be excited by post-hypnotic suggestion, which is useful in patients suffering from a morbid loss of appetite. Healthy subjects who have just eaten a hearty meal can be made to feel fresh hunger and go through another meal. Delboeuf, on the other hand, has induced loss of appetite by suggestion to such an extent and for so long a period that the person concerned took no solid food for fourteen days. Further, it is possible up to a certain point, to satisfy the hunger and thirst of subjects in deep hypnosis by merely suggesting food and drink.

One of the most certain effects is the regulation of the bowels. In chronically constipated subjects I have sometimes suggested that at a fixed time the bowels shall be evacuated, and such action occurs invariably. Similarly, their action has been arrested by posthypnotic suggestion.

The occurrence of the menstrual period can also be retarded and accelerated by post-hypnotic suggestion. I caused the menses to appear in an anaemic woman on a certain day—though not exactly to the hour suggested. My case may have been coincidence, but Forel experimented on a number of his female asylum attendants, and most successfully.

The secretion of milk, also, has been increased as well as arrested by suggestion. The old mesmerists reported many such cases. J. Grossmann reports a recent case; also Hassenstein. The latter casued copious flow of milk in a wet nurse in whom the secretion had ceased to flow. It had ceased, however, owing to excitement over the child's condition, and was renewed by suggesting away the excitement.

Post-hypnotic suggestion may also be applied for purposes of education.

Thus, I had a patient, a young man of twenty-five, who suffered from epilepsy in his youth, and whose education had thus been retarded. He was given more to sports than to reading, and would not apply himself at all to work. His mother brought him on account of certain bad habits, which she wished to have corrected, and as soon as I succeeded in hypnotising him and breaking him of these habits, she enquired whether I could not make him more diligent and induce him to apply himself to motor engineering, for which he had a gift. Thus it came about that I suggested to him that he would the same afternoon take his motor to pieces and put it together again, which he did as was reported to me next day. Another day I got him to read up certain books on the subject, and write out for me an abstract of a technical work on motoring; and, finally, I created in him an anxiety to perfect himself in this department, but instead of the casual way, to go and apprentice himself to a firm of motor manufacturers. No doubt all this might, have been done in the waking state, but I doubt whether that ardent desire could have been created without the hypnotic influence, and if he had not believed it was his own wish, he probably would have resisted any persuasion on the part of his parents, being naturally given to obstinacy and disobedience.

A better example of the educational influence is that of another boy who once knew French fairly well, but from want of practice forgot it. I hypnotised him, and told him that the same afternoon he would not be able to speak English, that no matter who came into the room he would, if addressed, answer them in French. Moreover, he would write a friendly letter in French to a number of acquaintances of his who could understand the language, including myself. When I made the suggestion I had no thought at all of the servants of the house, and it was highly amusing to find him speak to them in French only, which puzzled them considerably. But that afternoon revived his interest in the language, and he kept it up afterwards.

Another boy with a natural talent for music was told by me that he would compose during the day a "sonata" of his own, and play it to me when I called the next afternoon. By permission of the parents I brought a distinguished musician with me, and the boy played to us his composition, first in the hypnotic state and then in the waking state, and the approval of my musical friend was a source of great encouragement to the boy to persevere of his own will without further suggestion from me. My friend being in doubt that the boy was really hypnotised when he first performed the piece, I suggested to the youth that the drawing-room table was another piano. Would he try the effect of his composition on the new instrument ? He went through the finger movements in exactly the same way, though he seemed not to appreciate the new piano, for on enquiring which instrument he liked better, he answered "My own!"

The personal character may also be influenced by post-hypnotic suggestion. People are often so astonished at the effects of hypnotism when they watch the treatment that they request one sometimes to suggest various improvements in the personal character of the subject, or in his manners to particular relatives or acquaintances. Quarrelsome men and women have been thus rendered amiable in disposition, for their attention being drawn in the hypnotic state to their natural characteristics, they acted up to the suggestion, and exercised greater control afterwards over their tendencies. In others, over-sensitiveness has been reduced to a normal degree, and obstinacy and other undesirable characteristics have ben rectified. Worse faults still can be cured, as will be seen in the chapter on moral education.

One case is of interest, in which I was asked to suggest that a man who had lived at enmity with his brother for years for no very serious reason, should "make it up to him." The subject at first did not want to do so, but my persuasion and the argument that it is better to live in peace with the world in general, and still more so with one's relations, finally appealed to him. Anyhow, without using any commands, he promised he would make overtures to his brother to resume the friendly intercourse, and I was told afterwards that they became good friends again.