Popular Science Monthly/Volume 25/October 1884/The Physiological Aspect of Mesmerism
By J. N. LANGLEY, F. R. S.
SCATTERED about in the literature of the seventeenth and eighteenth centuries are many records of the cure of divers human maladies in simple and mysterious-seeming ways. Valentin Greaterakes, in Charles II's reign, was, we are told, "famous for curing various diseases and distempers by a stroak of the hand only." His power, he thought, was a special gift from Heaven. Many people, however, were not slow to say that he had dealings with the devil. In some cases wonders were wrought by touching the affected parts of the patient with a magnet. Maxwell, who in 1679 published a short treatise on magnetic medicine, attributed the cures brought about by this, and by some other unusual forms of medical practice, to the accumulation of a subtile fluid in the body of the patient. This subtile fluid was diffused through all things in nature; a fortunate few among men had an inborn power of controlling its distribution. Such men could cure all diseases; they could indeed, he says, by adding to their own proper quantum of fluid, make themselves live forever, were not the influence of the stars adverse.
In 1775 the theory of animal magnetism was put forward in Vienna by Friedrich Anton Mesmer. Neither his theories nor his facts differ very greatly from those of some of his predecessors. There exists, he said, in nature a universal fluid; in virtue of this, the human body possesses "properties analogous to those of a magnet; there are to be distinguished in it poles equally different and opposite, which may even be communicated, changed, destroyed, and restored; even the phenomenon of inclination is observed therein." By means of this magnetic fluid all the maladies of man could be healed. A few years later Mesmer left Vienna for Paris. At first he magnetized his patients by gazing steadily at them, or by means of "passes"; but, as patients became more numerous, he brought them into a proper magnetic condition by other methods, often of a very fantastic nature. The patients did not, when magnetized, all show the same symptoms: some passed into a heavy sleep, some became insensible to touch, or even to stimuli ordinarily painful; some became cataleptic, some were seized with local or general convulsions. This last condition was called a crisis, and was the triumph of the mesmerizer, the moment when the disease was considered to be forcibly expelled from the system. Nowadays it is the last state a physician would care to produce in a patient.
For a time Mesmer's success was enormous. His admirers subscribed for him a sum of nearly 350,000 francs, receiving in return details as to the method of magnetization. In Paris the belief in the power of Mesmer to cure diseases soon waned; but by this time he had made a stir in the world, and had drawn attention to a number of facts which were either only locally known, or largely disregarded. Mesmer devoted himself chiefly to curing patients, and it must be added, to receiving fees; but about ten years after the time of his coming to Paris it was found that a state resembling somnambulism, or sleep-walking, could be produced in some persons by magnetizing them. This gave a stimulus to the investigation of what I may call the magical side of the phenomena. This magical side had always been present, but in the height of Mesmer's power had not been much regarded. Of the magic of animal magnetism I will say one word more presently.
The term animal magnetism lingered long, but has now happily fallen into disuse, either mesmerism or hypnotism being used in its stead. "Hypnotism" we owe to Dr. Braid, of Manchester, who, from 1841 to the time of his death in 1860, subjected all the phenomena said to be produced in the magnetic state to a searching investigation. Braid is the founder of mesmerism in its scientific aspect. Hypnotism and mesmerism, as commonly used now, are synonymous terms; it would be advantageous, I think, if we could make a distinction between them. We might, for example, use the term hypnotism to embrace all those phenomena which are proved, and the term mesmerism to embrace all those phenomena which are not proved. Mesmerism would then mean what I have called its magical side, and would embrace those phenomena which are sometimes called the higher phenomena of mesmerism. These are of various kinds. It is said, for instance, that one person can, at any time he wishes, mesmerize another who is at a distance, and who is in perfect ignorance of the intentions of the mesmerizer; that a mesmerized person can perceive the thoughts and sensations of the mesmerizer, without receiving any indications from the known organs of sense; that a clairvoyant can see with parts of the body other than the eyes, for example, with the back of the head, or with the pit of the stomach; that a clairvoyant can describe places and persons which he has never read of, or heard of, or seen. Those observers who have done most to elucidate the subject, such as Braid, have failed to observe any of these and other similar higher phenomena. They are unproved. It would be convenient, I say, to include such phenomena only, under the heading of mesmerism; but this I can not yet venture to do. The facts I have to mention I shall call those of hypnotism or mesmerism indifferently. The magical side of the subject may, I think, at present be fairly left out of account.
The primary point in mesmerism is the paralysis of the will; the nervous system is then out of the control of the subject, whether animal or man, and, by appropriate stimulation, any one or more of his nerve-centers can be set in activity. I shall consider first the behavior of the lower animals when mesmerized: in these the phenomena, as far as at present observed, are much simpler than they are in man. If a frog be turned over on its back, it at once regains its normal position; if, however, it be prevented from doing so, and its struggles are for a short time gently suppressed, it becomes hypnotized. Then, although it be left at liberty to regain its normal position, it will not attempt to do so. Apart from the movements it makes in breathing, it lies motionless. If it has been held for a short time only, the hypnotic state does not last long, usually from one to five or ten minutes; but, if the movements it makes, say, at the end of one minute, or of five minutes, and so on, are suppressed, it will not infrequently happen that the frog will then stay without further movement for a considerable time, sometimes even for many hours. During the first part of this time a slight pinch, a sudden flash of light, or a loud noise, will usually cause it to turn over and sit up in its normal manner. For a moment or two it looks a little dull and confused, but rapidly regains its normal activity. During the latter part of this time it responds less and less to external stimuli. When it is in this state, it may be propped up against a support with its legs crossed under it, or placed so that it rests on its head, or placed on its side with its legs arranged in this or that fashion, without offering the least resistance.
I have spoken of the frog as being hypnotized or mesmerized. Let us consider what is meant by this. I think it is obvious that the animal does not remain passive from any astuteness on its part; it is incredible that the frog, finding its efforts to escape ineffective, should make up its mind to remain quiet, and should, although at liberty to move, stay still for hours, becoming more and more determined as time goes on to take no notice of noises, of flashes of light, and of pinching of its skin. On the contrary, it is, I think, obvious that in some way its will has become paralyzed. In order to attempt to explain how this is brought about, we must consider an aspect of reflex action which is very little understood.
A brainless frog will, when its leg is gently pinched, kick out the leg; but, if just previously some other part of the body has also been pinched, one of two opposite things may take place—the leg may be kicked out more quickly and vigorously, or it may not be kicked out at all. In both cases the nerve-center involved in producing the movement of the leg receives an additional impulse from another nerve-center, but in one case the additional impulse increases the activity of the nerve-center involved in the reflex action, in the other case it annuls this activity—there is, to use the physiological term, an inhibition of the "reflex" nerve-center.
Inhibition by impulses proceeding from the cortex of the brain occurs every day of our lives. The "will" is perpetually being brought into play to inhibit some nerve-center or other. For example, you may be on the verge of yawning, when it suddenly occurs to you that it will be better not to do so; you suppress the yawn without moving a muscle. What happens is this: An inhibitory nerve-impulse is sent from the cortex, and puts a stop to the indiscreet activity of a nerve-center elsewhere in the brain. Further, when the cortex is set in activity in a particular way by one impulse, another impulse reaching it may inhibit the first activity, or, in terms of the localization theory, one nerve-center in the cortex may send out inhibitory impulses to any other nerve-center of the cortex.
I need not further multiply instances of inhibition. I wish, however, to lay stress on this, that it is highly probable that impulses traveling from any peripheral nerve-ending to a nerve-center, or from any one nerve-center to any other, may, under certain circumstances, diminish or annul the functional activity of the nerve-center—that is, may inhibit it. And there is equal reason to believe that, under certain other circumstances, the effect produced will not be inhibition, but an increase of activity of the center. The exact conditions which determine whether one effect or the other takes place have not as yet been made out. For the present the facts must suffice us. We may now return to the mesmerized frog.
Whatever the will may be, its action is accompanied by a certain activity of the cortex of the brain; if this activity is prevented from taking place, the will can no longer act. From the physiological standpoint, then, the mesmerized frog lies motionless because an inhibition of a particular activity of the nerve-cells of the cortex has taken place. We may distinguish two chief causes of this inhibition.
The tactile stimuli sent to the central nervous system when the frog lies on its back are obviously different from those sent when the frog is in its normal position. The unusual nerve-impulses traveling from the skin in the unusual position of the frog are inhibitory nerve-impulses. There is reason to believe that they act first on some lower center of the brain, and that from this impulses are sent which diminish or annul the activity of the cortical nerve-cells which is necessary for the exercise of the will.
The second chief cause of inhibition is in the cortex itself. Handling the frog in the way which is done when it is mesmerized produces a certain emotional condition which we may call fright. But, when the animal is frightened, the nerve-cells of the cortex are set in activity in a special manner. This mode of activity inhibits other modes of activity, and the will is paralyzed. We can not at present, I think, put in any more definite form the effect of one state of the cortex of the brain upon its other possible states. We do not know enough of the relations of the cortex of the brain to the psychical functions to say more. In some cases fright seems to play a very small part, if any, in producing the effect. That it is not an essential factor is, to some extent, confirmed by the fact that a frog without the cerebral hemispheres can be easily mesmerized; it is difficult to conceive of the animal in this state being very much frightened.
It will be remembered that reflex action from all parts of the body is diminished in the mesmerized frog. After a time, then, there is a marked inhibition of activity of the whole nervous system. Now, in the brainless frog placed on its back there is no such diminution of reflex action; hence in the intact hypnotized frog the spinal cord must be inhibited by impulses coming from the brain; from which we may conclude that centers inhibited in their own proper action nevertheless send out inhibitory impulses to other centers. There appears, then, to be an irradiation of inhibitory impulses, just as we have seen that there is an irradiation of exciting impulses.
Before passing to mesmerism in man I will show you two other instances of hypnotism in the lower animals. The alligator which you see here behaves very much like the frog. It has, however, less tendency to become cataleptic. After a brief struggle, it becomes quiescent and its limbs slowly relax; its mouth may then be opened, and a cork placed between its teeth, without giving rise to any voluntary movement on its part. It may be kept for a considerable time in this limp condition by gently stroking the skin close to its eyes.
So far as I have observed, the hypnotic condition in birds and in lower mammals is not capable of any great development. It may last ten minutes, but rarely longer. In these animals, too, the emotional condition is probably the chief factor in producing the inhibition. Of impulses from peripheral sense-organs, tactile impulses seem to be most effective in the lower mammals, as in the rabbit and Guinea-pig, and visual impulses in the bird. The pigeon which I have here remains longest quiescent when, after it has been held for a minute or two, I bring my hand slowly up and down over its head.
In man the phenomena of mesmerism are of a very much more striking character than they are in the lower animals. Speaking generally, this seems to be due to a greater interdependence of the various parts of the nervous system in the lower animals. In these, when any one center is stirred up by exciting impulses, an irradiation of exciting impulses is apt to take place to all other centers, and the mesmeric state is in consequence apt to be broken. And on the other hand, when a center is inhibited, an irradiation of inhibitory impulses is apt to take place, and the whole nervous system is in consequence apt to be inhibited. Hence the activity or suppression of activity of particular parts of the central nervous system, which forms so conspicuous a feature of mesmerism in man, can be only partially produced in the lower vertebrates. Even in man there is very considerable difference, in different individuals, in the ease with which particular nerve-centers can be excited or inhibited without other centers being similarly affected. But apart from this the fundamental features are the same, whether a man or a frog be mesmerized. The primary point is, as I have said, the paralysis of the will—that is, the inhibition of a certain activity of the nerve-cells of the cortex of the cerebrum.
The great majority of people can not be mesmerized unless they consent to fix their attention on some particular object. This fixing of the attention, speaking generally, seems to be a voluntary exclusion of exciting impulses, leaving thus the inhibitory ones an open field. Idiots, who, on account of the lack of co-ordination of their nerve-centers, can not fix their attention for any length of time on any one object, can not as far as I know be mesmerized. Now this, now that part of the brain becomes active, and exciting impulses are sent out which overpower the inhibitory ones. Inhibition from impulses arising in the cortex itself are rare unless the patient has been previously mesmerized. Some such cases, however, do occur. But in people who have been previously mesmerized inhibition in this manner is of not unfrequent occurrence; within limits, the more often the changes in the cells accompanying inhibition have been produced, the easier they are to reproduce. Those who have often been mesmerized may fall again into this condition at any moment, if the idea crosses their minds that they are expected to be mesmerized.
Thus, if a sensitive subject be told that the day after to-morrow at half-past nine he will be mesmerized, nothing more need be done; the day after to-morrow at half-past nine he will remember it, and in so doing will mesmerize himself.
An instance sent by M. Richer to Dr. Hake Tuke, presents, it seems to me, an example of inhibition from the cortex which is of a somewhat different class, and more allied to that which occurs in birds and lower mammals. A patient was suspected of stealing some photographs from the hospital, a charge which she indignantly denied. One morning M. Richer found this patient with her hand in the drawer containing the photographs, having already transferred some of them to her pocket. There she remained motionless. She had been mesmerized by the sound of a gong struck in an adjoining ward. Here, probably, the changes in the cortex accompanying the emotion which was aroused by the sudden sound at the moment when she was committing the theft produced a wide-spread inhibition—she was instantaneously mesmerized.
I will show you the method of mesmerizing which is, perhaps, on the whole, most effective; it is very nearly that described by Braid. I have not time to attempt a mesmeric experiment to-night; it is the method only which I wish to show you. With one hand a bright object, such as this faceted piece of glass, is held thus, eight to twelve inches from the subject, so that there is a considerable convergence of the eyes, and rather above the level of the eyes, so that he is obliged to look upward. The subject is told to look steadily at the piece of glass, and to keep his whole attention fixed upon it. This position is kept up for five to ten minutes; during this time the pupils will probably dilate considerably, often assuming a slight rhythmic contraction and dilation; when this is the case, the free hand is moved slowly from the object toward the eyes. If the subject is sensitive, the eyes will usually close with a vibratory motion. In some cases the subject is then unable to open them, and the usual mesmeric phenomena can be obtained. If, when the operator brings his hand near the eyes of the subject, the subject instead of closing them follows the movements of the fingers, the whole proceeding is repeated, but the subject is told to close his eyes when the fingers are brought near them, but to keep them fixed in the same direction as before, and to continue to think of the object and that only. The operator then for some minutes makes "passes," bringing his warm hands over and close to the face of the subject in one direction. When the subject is inclined to pass into the cataleptic state, an indication of his condition may be obtained by gently raising his arm; if he is beginning to be mesmerized, the arm remains in the position in which it is placed. If the arm falls, the mesmeric state may not infrequently be hastened on by telling the subject to keep his arm extended while he is still gazing at the object, or while the passes are being made. And that is the whole of the process. The man thus mesmerized sinks from manhood to a highly complicated piece of machinery. He is a machine which for a time is conscious, and in which ideas can be excited by appropriate stimulation; any one acquainted with the machinery can set it in action.
The distinguishing feature of the earlier stages of mesmerism in man is that by slight stimulation any one center can be easily set in violent activity, and its activity easily stopped, without the activity spreading to other distant centers. It is on this that the mesmeric phenomena usually exhibited depend; with most of these phenomena you are no doubt familiar, so that I need mention one or two only.
Complicated reflexes may be produced in various ways, just as we have seen is the case with a frog even when without its cerebral hemispheres. Thus Braid mentions that on one occasion an old lady who had never danced, and who indeed considered it a sinful pastime, when mesmerized began to dance as soon as a waltz-tune was played.
A statement made to a subject will often produce implicit belief, notwithstanding the evidence of his senses. I remember telling a subject that I was about to bring a hot body near his face, and he was to tell me when it was painful. I put my finger on his cheek, upon which he cried out violently that I was burning him. When he was awakened he remembered that I had touched him with something very hot. The idea I had given him was remembered, the evidence of his sense of touch was disregarded.
There are certain attitudes which we usually assume under the influence of certain moods or ideas; from each of the muscles concerned in bringing about any one attitude, impulses travel up to the brain, and give rise to a definite muscular sensation which comes, therefore, to be associated with a particular mental mood. In mesmerized people the production of a definite muscular sensation not infrequently produces in the mind the mood with which it is, in the wakeful state, associated. At the same time ideas may be produced corresponding to the mood, and the ideas may give rise to particular actions, such as laughing, crying, fighting.
If the head is pushed back and the shoulders opened out, the face assumes a look full of pride or haughtiness, and, if the subject be asked what he is thinking about, he will give some answer indicating what a fine fellow he fancies himself to be. If, then, the head is bowed and the shoulders contracted, the aspect of the face changes to one of humility and pity. Occasionally it happens that a slight pressure on a single muscle, which causes it to contract, will by an irradiation of nerve-impulses produce the muscular sensations proper to a group of muscles, and this will give rise to the associated frame of mind. Thus very different feelings may be made to rapidly succeed one another in the mind of the subject by simply pressing on various muscles of the head and neck. At first sight such an experiment looks like a revival of the now happily forgotten phrenology.
I have said that, in a frog which remains mesmerized for any time, there is a considerable reflex depression—i.e., inhibition of the whole of the central nervous system; that there is an irradiation of inhibitory impulses. In man a similar irradiation of inhibitory impulses appears to take place: usually a mesmerized person if left alone passes gradually, but often rapidly, into a state of torpor; consciousness disappears, memory is lost, reflex action becomes difficult to obtain; finally, it may be, there is complete anæsthesia, a limb may be cut off without producing any movement or any pain. Since this torpor comes on without anything further being done to the subject, we may conclude that here, as in the frog, but to a much more marked degree, there is an irradiation of inhibitory impulses. The primarily inhibited centers send out inhibitory impulses to all other nerve-centers. Up to a certain stage, possibly throughout, any one or more centers may be brought back to a condition of activity by certain exciting stimuli, but when these cease the inexcitable condition is soon brought back by the inhibitory impulses streaming to them from other nerve-centers.
The extent to which the torpid condition develops itself varies in different individuals. It depends upon the condition of the nervous system, upon the relative intensities of the inhibitory and exciting impulses. As far as our present knowledge goes, it would appear that a few only of those who can be mesmerized can be made to pass into a condition of complete anæsthesia. It is possible, however, that this may be due to the passes which give rise to inhibitory impulses not being continued long enough. Dr. Esdaile, who in India was accustomed to mesmerize his patients before performing surgical operations upon them, used to continue the passes for one to two hours, and often to repeat this for several days in succession.
In different people the order in which different centers are inhibited varies, as we should expect, from the unequal development of different centers in different people. This is no doubt of influence in determining whether the general state is cataleptic, somnambulistic, or lethargic, and here probably the method used to mesmerize is also of considerable importance; it would seem that the cataleptic condition is more likely to be developed when the process of mesmerization involves a strain on the eyes of the subject than when he is mesmerized by passes. Not much attention, however, has as yet been directed to this point.
There can, I think, be no doubt that mesmerism may help, and sometimes cure, persons suffering from certain diseases of the nervous system. It is not in our power to make any accurate statement of the way in which this is brought about; but, since disease may be the result of either an over-activity or of an under-activity of any part of the central nervous system, it is reasonable to suppose that a beneficial effect will follow the employment of a method which allows us to diminish or increase these activities as we will. This is a side of the question which is of the greatest interest both to physicians and to physiologists—to physiologists, since it bears directly upon the problem of the influence of the nervous system on nutrition. There is good reason to believe that, by directing attention strongly to any particular part of the body, the nutritive state of that part of the body may be altered. The determination of the actual way in which this is brought about is full of difficulties, but the following way is at least theoretically possible: It may be that the nerve-centers connected with the tissue in question are made unusually active, and that they send out nerve-impulses of a trophic nature, that is, impulses which directly control the nutrition of the tissue. The alteration in the tissue caused by its changed nutritive state—its changed metabolism—may conceivably be either beneficial or detrimental to the whole organism; it may give rise to a diseased state, or get rid of an existing one.
The modern miracles of healing, wrought in persons in a state of religious enthusiasm, offer a field for investigating this problem; the field, however, is a particularly bad one, and chiefly because so many people concerned regard any careful examination of the subject as impious. But in mesmerized persons it seems probable that such investigations could be made on a fairly satisfactory basis. Men when mesmerized gradually lose remembrance of those things which they remember when they are awake, but not infrequently other things are remembered which are forgotten in the waking state. This is normally the case with a person who has been previously and recently mesmerized. He may then remember little else than what took place in the corresponding stage of his previous mesmerization. In a certain state, then, an event or a command will produce in the central nervous system those changes which are necessary for the event or the command to be remembered later, without ever rising to consciousness in the waking condition. Thus, a command to do a particular thing, given to a subject in this mesmeric stage, may be carried out when he awakes, although he is quite unconscious why he does it. We may say that such an act is one of unconscious memory. But it is, I think, something more than this. The subject is usually uneasy and preoccupied until the thing is done; he is, to a greater or less extent, unable to fix his attention on other things; he is, in fact, in a state of unconscious attention to an unconscious memory. This brings us to our point. It suggests that if a subject, in a certain stage of mesmerization, be told that in a few days a sore will appear upon his hand, or, conversely, that a sore already there will disappear, the conditions which accompany conscious expectation and attention will, to a certain degree, be established; and the trophic influence of the nervous system on the tissues may be tested in a manner which puts the experiment fairly within the control of the observer, and, to a certain degree, excludes imposture. Such an experiment has obviously some drawbacks: it would probably only succeed, if it succeeded at all, with a person whose nervous system was in a state of unstable equilibrium; and it can hardly be expected that the effects would be so striking as when conscious expectation is also concerned. Still, observations of this kind are well worth attention, on account of the medical, the physiological, and the psychological issues involved in the results.
Here I must leave the subject. I have not attempted to give an account of all the phenomena of mesmerism; I have taken those phenomena which seemed to me to be the least easy to understand, the most liable to misconception, and have attempted to show that they resemble fundamentally certain simpler phenomena which can be observed in lower animals. I have further attempted to string together the various facts upon a thread of theory, which may be briefly summed up as follows:
The primary condition of mesmerism is an inhibition of a particular mode of activity of the cortex of the brain, in consequence of which the will can no longer be made effective.
This inhibition may he brought about by nervous impulses coming from certain sensory nerves as those of sights touchy hearing.
It may also be brought about by impulses or changes arising in the cortex itself.
The inhibited cortex, and probably also inhibited lower centers of the brain, send out inhibitory impulses to all other parts of the central nervous system, so that the mesmerized man or animal gradually passes into a state of torpor, or even of complete anæsthesia.
The phenomena of the excitable stage of mesmerism are proximately determined by the possibility of exciting any particular center alone, without exciting at the same time other centers by which its activity is normally controlled. In lower animals this stage is less marked in consequence of a greater interdependence of the various parts of the central nervous system.
I would expressly state that I regard this theory only as provisional. Further, I am quite conscious that it is very imperfect. A complete explanation of the phenomena of mesmerism and of its allied states can only be given when we have a complete knowledge of the structure and functions of all parts of the central nervous system. But I have not much doubt that the explanation of the main features of mesmerism will be found when we are able to answer the question, What is inhibition? And it is some comfort to think that the answer awaits us in the comparatively simple nervous system of the lower animals. I would not be understood to mean that variation of blood-supply and various other events are of no influence in producing mesmeric phenomena; I think, however, that these events are of secondary importance only.