Finally, automatic movements can be induced; and if the hands, for instance, are started rotating round and round they will continue to do so. If ordered to continue, the subject will be unable to stop them, no matter how hard he tries. Automatic writing may reveal forgotten events.

Among the most important phenomena which can be produced are marked changes in sensation. These present all variations between increased sensitivity and anaesthesia. People who are inclined to doubt that suggestion can produce such extraordinary feelings have only to consider how the thought of insects crawling on the body in the full waking state will rapidly induce itchiness and irritation.

All sorts of tingling, numbness, burning or feelings of cold can be produced. The sensation of touch can be abolished, as can that of temperature, so that a lighted match can be held close under the hand and the patient will feel nothing.

The most practical application of this is that the sensation of pain can be removed so that hypnosis can be used as an anaesthetic or analgesic in certain cases. In good subjects or those who have been trained, it is possible to carry out even major operations under the influence of hypnosis.

It has been used a good deal in dental work and obstetrics. The difficulty is that not all subjects can achieve any significant degree of anaesthesia or analgesia. Very often the pain is greatly reduced rather than completely abolished.

When successful, as in a good subject, the anaesthesia is very real, and scientific tests have proved that the subject really does not feel any pain and is not merely acting.

Phenomena involving the special senses are of great importance. Each of the senses may be hallucinated; and in the case of taste, for instance, the subject will chew up and swallow with great relish the nastiest thing if told that it is something sweet. If told that he is smelling a nice perfume, the patient will inhale even the fumes of strong ammonia with the greatest of pleasure.

In deep somnambulism there may be both positive and negative hallucinations of vision. The eyes may be opened and the subject will see anything the hypnotist suggests and behave accordingly. For instance, he may pat an imaginary dog or run away from a wild animal. In very deep somnambulism negative hallucinations may be possible so that the subject cannot see an object, although he may be looking directly at it.

In the same way auditory hallucinations may be induced, both positive or negative. The subject may ‘hear’ an imaginary orchestra or ‘voices’ while, on the other hand, he can be rendered completely deaf to even the loudest noise, such as a pistol shot close to the ear.

It has been proved by scientific tests that the subject is not merely playing a part. When blindness is suggested, then brain waves such as are found in this condition appear. When vision is restored, then the brain waves characteristic of blindness cease.

Many apparently ‘occult’ phenomena depend upon these hallucinations. Such a thing as ‘crystal gazing’ has long been regarded with superstitious awe, but a deeply hypnotized person can gaze into a crystal or mirror and see anything the hypnotist suggests. Use is made of this to recover buried material in the mind for the purpose of analysis.

All the senses are exalted in hypnosis. Hearing is improved, the power of smell is increased, and vision is undoubtedly keener. Many subjects are able to pick out blank cards which would be indistinguishable from one another in the waking state. They are able to do this apparently by noting very slight flaws which would escape detection when awake. This apparently remarkable feat is not so extraordinary when it is remembered that professional gamblers can pick out cards which are marked so cleverly that ordinary people are unable to notice them.

Another interesting phenomenon which can be obtained under hypnosis is that of age regression. The patient may be regressed back to any age, and a good subject will reproduce all the characteristics of that particular age. Even the handwriting will change, and intelligence tests seem to prove that the patient is really back at the age level suggested. In spite of this there is some doubt as to whether the patient is really regressed or whether he is acting as he thinks a person of that age should do.

Tests seem to indicate on the whole that regression is genuine. Certainly patients who are able to do this (that is, those who can enter a deep trance) can recall past events far more accurately and vividly than they could otherwise do.

Dreams may be suggested during hypnosis, and it can be arranged for them to occur during the trance or during normal sleep at some later date. The patient may be instructed to have a dream which will have a bearing on his condition; and it may be possible in certain cases to gain an insight into his problems in this manner.

In the literature there are many reports suggesting that hypnotic subjects have an extraordinary sense of time. Experiments are often quoted to prove this, stating that the patient carried out a certain action after a certain number of minutes. Practically this does seem to occur, and patients will carry out a suggestion with remarkable accuracy as to time. After all, very many people can wake at a definite hour if they give themselves an order just before going to sleep.

Still another phenomenon is the increased ability of the patient to play a part very realistically. When told he is Napoleon, the patient will act like Napoleon in a very convincing manner. Further, it is often possible to cause distinct changes in personality during hypnosis and even to create multiple personalities. As will be seen later, a knowledge of this phenomenon enables us to understand spiritualistic seances with mediums and their ‘guides’.

Of great importance in medicine is the increased control over the autonomic nervous system under hypnosis. Fakirs and Yogis make use of hypnosis, self induced, to gain their extraordinary control over bodily functions. Undoubtedly, it is possible to vary the blood supply—for instance, to control blushing or to send more blood to a certain part of the body.

It is easy to produce vomiting and digestive changes, and to regulate the bowels and even menstruation. These changes are usually brought about by suggestions acting through the emotions rather than direct commands. Blood pressure, for instance, is lowered as a result of suggestion of relaxation - not as a direct command. It is possible, however, to increase or slow the heart rate by direct suggestion.

Probably the most important phenomenon in hypnotism is the post - hypnotic suggestion. Suggestions made during the trance are carried out after waking exactly as ordered.

As all the phenomena which can be obtained during the trance may be obtained post-hypnotically, this is obviously of great importance. Curative suggestions may often be carried out after a light trance, but those of a bizarre nature are usually only effective after a deep trance, particularly if there has been amnesia. The patient feels compelled to carry out the suggestion. Sometimes it is possible to resist, but only at the expense of considerable uneasiness; and the patient does not feel happy until he has done what was suggested. In this way a post-hypnotic suggestion has practically the identical force and compulsion of an obsession.

Use is made of the post-hypnotic suggestion for curative purposes and to make hypnosis easier. By means of this the patient may be trained to go into hypnosis at any given signal instantaneously.

Post-hypnotic suggestions may keep their full force for years, and cases have been reported as responding to the suggestion after even twenty years.

Another important phenomenon of hypnosis is amnesia. The very deep trance is usually followed by amnesia, although this is not always so. It is more likely to occur if suggested by the hypnotist. In any subsequent trance full memory of all that occurred in the first can be obtained. By constant probing and questioning, memory can often be brought back even in the waking state. It was this fact that led Freud to develop psycho-analysis.

Post-hypnotic amnesia is not always complete, even after a deep trance, and there is some evidence to show that it is not real. Scientific tests show that subjects still react to conditioned reflexes, which have been set up during deep hypnosis, in the waking state. If the amnesia were real, they would have forgotten all about them and so remained indifferent.

Nevertheless, after a very deep trance the patient usually maintains that he has no memory of the events.

For most medical purposes it is rarely necessary to use anything more than the light stage of hypnosis if the proper technique is employed. Light hypnosis is quite sufficient to enable the patient to relax, and so break the vicious circle of fear, anxiety, tension, and symptoms. It is equally easy for him to recall under its influence events which he may have forgotten, and to realize exactly how his condition started. Knowledge and understanding remove fear, and then constructive suggestions, formulated in the light of what has been revealed of the origin of the patient’s complaint, are quite sufficient to re-educate the patient under the influence of light hypnosis, for if only 51 % of the mind can be influenced favourably, it will outweigh the other 49 %.