Part 33 (1/2)
Examples of this sort of thing are innumerable and they teach that whenever any questionable a.s.sertion is made about a thing heard the doctor must be called in to determine whether the witness heard it under abnormal, though not diseased conditions. Again, merely accidental or habitual general excitability tends to intensify all sounds, and whether the witness under consideration was in such condition can be determined only by the expert physician.
The illusions of hearing which completely normal people are subject to are the most difficult of all. Their number and frequency is variously estimated. The physician has nothing to do with them. The physicist, the acoustician and physiologist do not care about the criminalist's needs in this matter, and we ourselves rarely have time and opportunity to deal with it. As a result our information is very small, and no one can say how much is still undiscovered. One of my friends has called my attention to the fact that when the beats of the clock are counted during sleepiness, one too many is regularly counted. I tested this observation and my experience confirmed it. If, now, we consider how frequently the determination of time makes the whole difference in a criminal case and how easily it is possible to mistake a whole hour, we can get some notion of the importance of this illusion. Its explanation is difficult and it may be merely a single instance of a whole series of unknown auditory illusions resting on the same basis. Another and similar phenomenon is the ”double beat of the hammer.” If you have an a.s.sistant strike the table with a hammer while you hold both ears with your fingers and then open them half a second or a second after the blow, you hear the blow again. And if you open and shut your ears quickly you can hear the blow several times. This is explained through the fact that a number of reflections of the sound occur in the room, and that these are perceivable only by the unfatigued ear. The explanation is unsatisfactory because the experiment is sometimes successful in the open. Taken in itself, this matter seems very theoretical and without practical value. But this kind of action may occur
automatically. It is well known that swallowing closes the Eustachian tubes for a moment, especially if done when lying down. Now, if this occurs during a blow, a shot, etc., the sound must be heard twice. Again, it may easily happen that because of the noise a man wakes up half asleep and, frightened, swallows the collected saliva; then this accident, which in itself seems unimportant, may lead to very significant testimony. Such occurrences are not infrequent.
The intensity of a sound already heard may be of considerable influence. Certain experimenters have indicated the remarkable character of slightly intensive effects of sound. If you hold a watch so far from the ear as to hear it clearly but weakly, the sound decreases until finally it is not heard at all, and after awhile it is again heard, etc. This may lead to hearing distinct sounds made up of many tones, and need not evince any great illusion with regard to the ticking of a watch. But the thing may occur also in connection with more powerful and more distant sounds, e. g., the murmur of a brook, the rush of a train, the pounding in a distant factory. Noises far removed are influenced by reflections of sound, waves of air, etc., and it is possible that all kinds of things may be heard in a completely monotonous noise. This can be easily learned by listening to the soft murmur of a distant brook at night. Given the disposition and supposing the existence of the brook unknown, it is easy to hear in its monotonous murmur, human voices, sighs, shrieks, etc.
Another remarkable observation shows that in the dark very distinct things are heard during the playing of delicate instruments, such as mouth-organs. The humming approaches and withdraws, then it comes on various sides, and finally one has the feeling that the whole room is full of humming and winging insects. And this may go on indefinitely. There is a large collection of reasons for this reduplication of monotonous sounds. Everybody knows the accord of the
only one cry. Difference in distance and alterations in the air cause the chords.
The difficulties in distinguis.h.i.+ng the intensity or weakness of a sound are of importance. Fechner learned from the violinist Wasilewski that he observed that a male choir of four hundred voices did not sound essentially louder than one of two hundred. At the same time one clock is not heard at a great distance, a hundred clocks are heard. One locust can not be heard eating; when 1000 eat they are heard; hence each one must make a definite noise.[1] Early authorities have already indicated how difficult it is to distinguish the number of bells ringing together. Even musicians will often take two or three to be five or six.
Certain dispositions make some difference in this respect. The operating physician hears the low groaning of the patient after the operation without having heard his loud cries during the operation. During the operation the physician must not hear anything that is likely to disturb his work, but the low groan has simply borne in upon him. The sleeping mother often is deaf to considerable noise, but wakes up immediately when her child draws a deeper breath than usual. Millers and factory hands, travellers, etc., do not hear the pounding of their various habitual environmental noises, but they perceive the slightest call, and everybody observes the considerable murmur of the world, the sum of all distant noises, only in the silence of the night that misses it.
Illusions of direction of sound are very common. It is said that even animals are subject to them; and everybody knows how few human beings can distinguish the source and direction of street music, a rolling wagon, or a ringing bell. Even when long practice enables one to determine direction with correctness, an accidental event, perhaps the weather, especial sounds, a different grouping of individuals on the street, may result in serious mistakes. I tried to learn to judge from my office-desk whether the ring of the horse- car came from above or below. I succeeded so well that I could not understand how it was difficult not to learn the difference, and yet I failed many a time altogether in judgment. The reason for it I do not know.
All these enumerated circ.u.mstances must show how very uncertain all acoustic perceptions are, and how little they may be trusted if they are not carefully tested under similar conditions, and if-what is most important-they are not isolated. We are here led back
[1] Max Meyer: Zur Theorie der Ger
to the old principle that every observation is not proof but means of proof, and that it may be trusted only when it is confirmed by many parallel actions which are really consistent. That even after that mistakes are possible, is true, but ”after that” is when we have done all that lies within human power.
Section 101. (4) Illusions of Touch.
The high standing of the sense of touch which make it in certain directions even the organ of control of the sense of sight, is well known, and Condillac's historic attempt to derive all the senses from this one is still plausible. If what is seen is to be seen accurately there is automatic resort to the confirmatory aid of the sense of touch, which apprehends what the eye has missed. Hence we find many people touching things, whose vision is not altogether reliable- i. e., people of considerable age, children unpracticed in seeing, an uneducated people who have never learned to see quickly and comprehensively. Moreover, certain things can be determined only by touching, i. e., the fineness of papers, cloth, etc., the sharpness or pointedness of instruments, or the rawness of objects. Even when we pat a dog kindly we do so partly because we want to see whether his skin is as smooth and fine as the eye sees it; moreover, we want to test the visual impression by that of touch.
But important and reliable as the sense of touch is, it is nevertheless not to be trusted when it is the sole instrument of perception. We must never depend on the testimony of a witness based entirely on perceptions by touch, and the statements of a wounded person concerning the time, manner, etc., of his wound are unreliable unless he has also seen what he has felt. We know that most knife and bullet wounds, i. e., the most dangerous ones, are felt, in the first instance, as not very powerful blows. Blows on the extremities are not felt as such, but rather as pain, and blows on the head are regularly estimated in terms of pain, and falsely with regard to their strength. If they were powerful enough to cause unconsciousness they are said to have been very ma.s.sive, but if they have not had that effect, they will be described by the most honest of witnesses as much more powerful than they actually were. Concerning the location of a wound in the back, in the side, even in the upper arm, the wounded person can give only general indications, and if he correctly indicates the seat of the wound, he has learned it later but did not know it when it occurred. According to Helmholtz,
practically all abdominal sensations are attributed to the anterior abdominal wall. Now such matters become of importance when an individual has suffered several wounds in a brawl or an a.s.sault and wants to say certainly that he got wound A when X appeared, wound B when Y struck at him, etc. These a.s.sertions are almost all false because the victim is likely to identify the pain of the moment of receiving the wound with its later painfulness. If, for example, an individual has received a rather long but shallow knife wound and a deep stab in the back, the first will cause him very considerable burning sensation, the latter only the feeling of a heavy blow. Later on, at the examination, the cut has healed and is no longer painful; the dangerous stab which may have reached the lung, causes pain and great difficulty in breathing, so that the wounded man a.s.signs the incidence of the stab to the painful sensation of the cut, and conversely.
Various perceptions of victims on receiving a wound are remarkable, and I have persuaded a police surgeon of considerable learning and originality to collect and interpret his great ma.s.s of material. It is best done by means of tabulation, accurate description of wounds according to their place, size, form, and significance, the statement of the victim concerning his feeling at the moment of receiving the wound, the consequences of healing, and at the end explanatory observations concerning the reasons for true or incorrect sensations of the victim. As this work is to have only psychological value it is indifferent whether the victim is veracious or not. What we want to know is what people say about their perception. The true and the false will distinguish themselves automatically, the material being so rich, and the object will be to compare true subjective feelings with true subjective deeds. Perhaps it may even be possible to draw generalizations and to abstract certain rules.
There are many examples of the fact that uncontrolled touch leads to false perceptions. Modern psychophysics has pointed to a large group of false perceptions due to illusions of pressure, stabs, or other contact with the skin. The best known, and criminalistically most important experiments, are those with open compa.s.ses. Pressed on the less sensitive parts of the body, the back, the thigh, etc., they are always felt as one, although they are quite far apart. The experiments of Flournoy, again, show how difficult it is to judge weights which are not helped by the eye's appreciation of their form and appearance. Ten objects of various forms were judged by fifty
people for their weight; only one discovered that they all had the same weight.
Similarly, mere touch can not give us proper control over the organs of the body. Sully says that in bed we may voluntarily imagine that a leg has a position quite different from that it really has. Let me cite some similar examples from my ”Manual for Investigating Judges.” If we take a pea between the thumb and the index finger, we feel the pea simply, although its tactile image comes to us through two fingers, i. e., double. If now we cross the third finger over the fourth and hold the pea between the ends of these two fingers, we feel it to be double because the fingers are not in their customary positions and hence give double results. From one point of view this double feeling is correct, but when we touch the pea naturally, experience helps us to feel only one pea. Another example consists in crossing the hands and turning them inward and upward, so that the left fingers turn to the left and the right fingers to the right. Here the localization of the fingers is totally lost, and if a second person points to one of the fingers without touching it, asking you to lift it, you regularly lift the a.n.a.logous finger of the other hand. This shows that the tactile sense is not in a very high stage of development, since it needs, when unhelped by long experience, the a.s.sistance of the sense of sight. Perceptions through touch alone, therefore, are of small importance; inferences are made on the basis of few and more coa.r.s.e characteristic impressions.
This is shown by a youthful game we used to play. It consisted of stretching certain harmless things under the table-a soft piece of dough, a peeled, damp potato stuck on a bit of wood, a wet glove filled with sand, the spirally cut rind of a beet, etc. Whoever got one of these objects without seeing it thought he was holding some disgusting thing and threw it away. His sense of touch could present only the dampness, the coldness, and the motion, i. e., the coa.r.s.est traits of reptilian life, and the imagination built these up into a reptile and caused the consequent action. Foolish as this game seems, it is criminalistically instructive. It indicates what unbelievable illusions the sense of touch is capable of causing. To this inadequacy of the tactile imagination may be added a sort of transferability of certain touch sensations. For example, if ants are busy near my seat I immediately feel that ants are running about under my clothes, and if I see a wound or hear it described, I often feel pain in the a.n.a.logous place on my own body. That this may lead to considerable illusion in excitable witnesses is obvious.
Finally, this dependence of the sense of touch may be supplemented by the fact that it is counted only relatively, and its value varies with the individual. We find the cellar warm in winter and cold in summer, because we only feel the difference with the outer air, and when we put one hand in hot, and the other in cold water, and then put both in tepid water one finds the tepid water cold, the other warm. The record of tactile sensations is frequent in our protocols and requires constant consideration of the sense's unreliability.
Diseased conditions are of course to be referred to the physician. I need only mention that slight poisonings by means of chloroform, morphine, atropine, daturine, decrease, and that strychnine increases the sensitivity of the touch organ.
Section 102. (5) Illusions of the Sense of Taste.
Illusions of taste are of importance for us only in cases of poisoning in which we want the a.s.sistance of the victim, or desire to taste the poison in question in order to determine its nature. That taste and odor are particularly difficult to get any unanimity about is an old story, and it follows that it is still more difficult clearly to understand possible illusions of these senses. That disease can cause mistaken gustatory impressions is well known. But precedent poisoning may also create illusions. Thus, observation shows that poisoning by rose-santonin (that well-known worm remedy to which children are so abnormally sensitive) causes a long-enduring, bitter taste; sub-cutaneous morphine poisoning causes illusory bitter and sour tastes. Intermittent fevers tend to cause, when there is no attack and the patient feels comparatively well, a large number of metallic, particularly coppery tastes. If this is true it may lead to unjustified suspicions of poisoning, inasmuch as the phenomena of intermittent fever are so various that they can not all be identified.
Imagination makes considerable difference here. Taine tells somewhere of a novelist, who so graphically described the poisoning of his heroine that he felt the taste of a.r.s.enic and got indigestion. This may be possible, for perhaps everybody has already learned the great influence of the false idea of the nature of a food. If some salt meat is taken to be a sweet pastry, the taste becomes disgusting because the imaginary and the actual tastes seem to be mixed. The eye has especial influence, and the story cited and denied a hundred times, that in the dark, red wine and white wine, chicken and goose,
can not be distinguished, that the going out of a cigar is not noted, etc., is true. With your eyes closed it may be possible to eat an onion instead of an apple.
Prior tastes may cause significant gustatory illusions. Hence, when a.s.sertions are made about tastes, it is always necessary to inquire at the outset what had been eaten or drunk before. Experienced housewives take this fact into consideration in setting their tables and arranging their wines. The values of the wines are considerably raised by complete illusions of taste. All in all, it must not be forgotten that the reliability of the sense of taste can not be estimated too low. The illusions are greatest especially when a thing has been tasted with a preconceived notion of its taste.
Section 103. (6) The Illusions of the Olfactory Sense.
Olfactory illusions are very rare in healthy people and are hence of small importance. They are frequent among the mentally diseased, are connected in most cases with s.e.xual conditions and then are so vivid that the judge can hardly doubt the need of calling in the physician. Certain poisons tend to debauch the olfactory sense. Strychnine, e. g., tends to make it finer, morphine duller. People with weak lungs try, in most cases, to set their difficulty of breathing outside themselves and believe that they are inhaling poisoned air, coal-gas, etc. If one considers in this connection the suspiciousness which many people suffering from lung trouble often exhibit, we may explain many groundless accusations of attempted murder by stifling with poisonous or unbreathable gas. If this typical illusion is unknown to the judge he may find no reason for calling in the physician and then-injustice.