TREMBLING

I

The old physiologists believed that the mind of brutes only obeyed two stimuli—pain and pleasure, and that all processes of their organism had as aim to avoid the bad and procure the good. Albrecht von Haller combated this opinion in the last century. 'This theory’, he says, 'does not in any way accord with the phenomena. If you consider the movements of an animal during fear, in imminent danger, as having preservation of life for their object, is there anything more absurd than the trembling of the knees and the sudden weakness which befalls it? I am persuaded that all phenomena of fear common to animals are not aimed at the preservation of the timid but rather at their destruction. In order to preserve a just balance it is necessary that the more prolific animals should be destroyed by the less prolific, therefore necessary that those animals destined to be the prey of others should not be able to defend themselves easily’.[15]

I think Charles Darwin must not have been acquainted with this explanation of trembling, as I am convinced he would otherwise have tried to combat it, or would at least have mentioned it in his writings. He was much too conscientious to ignore an objection made to his theories.

Here we have the example of another phenomenon which seems to contradict certain hypotheses of Spencer and Darwin. If it is true that, in the struggle for existence, animals have always perfected those capabilities which are most useful to them in defending themselves, and have gradually left behind, with the generations that have succumbed, all dispositions of the organism which were pernicious to the preservation of the species, why have they not succeeded in freeing themselves from trembling? Why, on the contrary, in critical, decisive moments, when danger confronts them, when their existence is threatened, when nothing is more imperative than flight, attack or defence, do we see animals paralysed with trembling, incapable of struggling, and perishing without their strength having in the least profited them? As Haller’s hypothesis is not sufficient to justify such a serious imperfection in organisms, we must seek the reasons and causes of this phenomenon elsewhere.

II

Charles Darwin, in his celebrated book on the 'Expression of the Emotions,’ says: 'Trembling, which is common to man and to many, or most, of the lower animals, is of no service, often of much disservice, and cannot have been at first acquired through the will, and then rendered habitual in association with any emotion.’[16] He then remarks that trembling is a very obscure phenomenon, and drops the subject.

Paolo Mantegazza accuses Darwin of great negligence with regard to this important problem, and says in his estimable work on 'Physiognomy and Mimicry,’ 'Darwin confesses that he does not consider trembling during fear useful; but, according to my experimental studies of pain, I find it most serviceable, as it tends to generate warmth, to heat the blood which is inclined to grow too cold under the influence of fear.’[17]

Since I must take part in this controversy, there is no other way but to examine attentively the various conditions of the organism in which trembling occurs, and then discuss the matter without prejudice. I acknowledge that I approach this task with some trepidation, because Mantegazza’s authority in physiology is so great that even Darwin’s name scarcely encourages an independent opinion. Let us consider the facts.

When we see horses, dogs, or men tremble from fear in the height of summer, at a temperature of 37°, and under the burning rays of the sun, one is inclined to think it is not from any necessity of warming themselves, all the more because monkeys, elephants, and many other animals always found at the equator tremble when they are frightened, even in their tropical countries.

In fever our teeth chatter while the temperature of the body is over 40°, and human economy, far from seeking to heat the blood by trembling, seems rather to stand in need of some mechanism which would cool it, so as to preserve life. After severe exertion or protracted work with the arms, our hands tremble, even when we are panting with heat. When exhausted after the forced marches which I had to make during my studies of fatigue, I have noticed that in the evening, on my return from the peak of Monte Viso or from the highest glaciers of Monte Rosa, my legs trembled, although the temperature of my body was one or two degrees above the normal. Tea, alcohol, coffee, and many stimulating medicines cause a very visible tremor. In convulsive laughter, pleasure, intoxication, voluptuous enjoyment, anger, when the necessity for heating the blood is certainly not apparent, one trembles also, the voice vibrates and the legs shake. All this makes it probable that Darwin is right, and more decidedly do I incline to his side when I think of the disastrous effects which trembling produces during fear. Seals and many animals, of which I shall speak more in detail in the chapter on Fright, tremble so violently that they cannot make their escape, and allow themselves to be overcome and miserably killed. How can we, amongst the sublime perfections which we admire in organisms, admit the contradiction that an animal, in order to warm itself, does not flee from danger but trembles till it is killed, whereas in running away, it could warm itself much better and save its life as well? But the question must not be judged in this way. The divergent opinions which arise in the interpretation of facts are most difficult to resolve in science, because to one of the adversaries there always remains a certain territory in which he may intrench himself.

III

In order to learn the actual nature of trembling we must first see how the muscles are made and how they act.

If we look at a muscular filament as fine as a hair under the microscope, we see that it consists of nearly a hundred extremely fine fibrillÆ lying close to each other in the form of bundles. It is these which together form those minute threads seen with the naked eye in fibrous meat. Each fibril, seen under a powerful microscope magnifying three or four hundred times, appears formed of a series of muscular elements, or, let us say, of so many little boxes, piled one on the top of the other like a battery and about two-thousandths of a millimetre in thickness. Each little box is prismatic in form and terminates in two flat ends. It was an English physiologist who described these little boxes for the first time; they are therefore known in science as Bowman’s muscular elements. The resemblance of each fibril to a voltaic pile is so great that some have tried, but in vain, to establish an analogy between their functions.

The nerves which go to the muscles send their branches to every fibre, like the fine cords of a match which serve the purpose of firing the powder in the mines at a distance, or, to make use of another simile nearer the truth, although still very far from reality, like the thin wire which conducts the electric spark to a cartouch of dynamite. When the nerve discharges its influence into the muscles, a very rapid molecular change takes place in the substance contained in the cartouches or muscular boxes, which contract, pressing their ends close together. Scarcely has the action of the nerves ceased than they relax and resume their previous form. It is well known, that when a muscle contracts, it becomes thicker and shorter; it suffices to take hold of the arm a little above the elbow and then to bend it in order to feel how the biceps muscle swells and hardens. Wherever a muscular contraction is produced, we may always imagine it as the transverse thickening of an innumerable series of little prismatic boxes, which at the same time shorten in the direction of the fibres.

The blood, which circulates in all the most remote corners of the organism, brings, so to speak, fresh explosive materials to charge the muscles again, cleansing it also from the soot and scoriÆ. The movement of the blood in the cells and fibres of the body is like a brook flowing through a village, from which every house may draw water for its needs, and into which any useless articles may be thrown and so carried away.

If we stop our ears with our fingers, we hear a dull noise, like the distant roar of cannon or a prolonged peal of thunder. This thunder is produced by the contraction of the muscles, for the nerves do not exercise a constant action on the fibres, but develop their influence in very rapid, irregular shocks, like the rattle of musketry in a battle.

It is seldom that a nervous discharge takes place all at once, like a volley of shot, in order to produce an instantaneous contraction, or, as physicians would say, a clonic contraction. Generally the discharges in muscular exertion begin in a few fibres; when these become weak, others come to reinforce the contraction; these cease, and others are charged; those are exhausted and others take up their work; thus a continuous tension of the muscle may be maintained. We must, therefore, consider the contraction of a muscle as an extremely rapid trembling of its most minute parts. When we become weaker through illness or from any other cause, we tremble because the contractions are so drawn out and distended as to show the elements composing them. If we poison a frog with some substance which diminishes the vitality of the nerves, there is a trembling of the legs at every exertion which the animal makes to move. In the violent and fatal contractions of tetanus, one can hear the muscular noise even at a distance. Those poor dogs which we see in the street cruelly poisoned with strychnine send forth during their convulsions, if laid on a sounding-board, a characteristic sound which arises from the extremely rapid vibrations of their muscles. It is the sound of tetanus.

IV

Trembling may be produced by two opposite causes, either by an excessive development of nervous tension, or by weakness. 'Les tremblements ont deux diverses causes: l’une est qu’il vient quelquefois trop peu d’esprits du cerveau dans les nerfs, et l’autre qu’il y en vient quelquefois trop.’ Descartes told us this two hundred years ago.

If we bend the forearm forcibly against the upper arm, as though to touch the shoulder with the clenched fist, we notice at once that our hand trembles, because the discharges, by means of which the contractions are produced and regulated, do not exactly answer their purpose. If we press the butt of the musket too firmly against our shoulder, or shoot with a heavy gun, we hit the mark less easily because of the trembling of our arms. We may, however, in a great measure correct these physiological imperfections; thus it is that a few months of practice in drawing will enable anyone to draw straight lines and to outline with a firm touch.

In order to understand the whole mechanism of trembling, we must remember that in grasping an object, we not only make use of those muscles which bend the fingers but also of those which serve to open the hand. The work of the muscles which oppose a movement, and which are therefore called antagonistic, is extremely efficacious, and is indeed indispensable in order to graduate and regulate muscular actions with accuracy. When we wish to move our eyes, all the muscles enter into tension, but one prevails and guides them to the desired point. When we take hold of the pen to write, we do not only bend the flexors of the fingers but also involuntarily contract the extensors. Without this it would be impossible suddenly to arrest the hand, the eyes, or any other part of the body in rapid motion.

Exhaustion or over-excitement of the nerve-centres destroys the harmony of aim of muscular contractions. The hand trembles, because the tension of the flexors and extensors is no longer evenly and firmly, but jerkily maintained. If we endeavour to keep the arm stretched out, we find we are not able to regulate the nervous discharges in such a manner as to preserve the equilibrium of the muscles during work, they relax and contract alternately on one side or the other; scarcely do the flexors give way, than the antagonist muscles succeed in bending the arm in their direction, then these shorten in their turn, rapidly resuming their previous position; but no sooner has an effort been made by the muscles of the other side, than they are again overcome by the antagonists. In this way a perpetual wavering is brought about, and the organs of the body sway, waver, or tremble according to the rapidity with which the muscles relax, without the will being able to control them.

In joy and intense pain there is a degree of emotion in which the intonation of the voice is changed, because the nerves which move the muscles of the larynx no longer regularly adjust the vocal cords. This is the origin of the tremolo which serves to heighten the pathetic expression in singing. Many are scarcely able to speak, but stammer under the influence of an emotion. It is difficult to pitch a loud note and sustain it with expanded chest without the voice trembling; in the same way one cannot scream for any length of time without the voice turning shrill and harsh, because the muscles tire and the movements of the larynx can only be imperfectly regulated; similarly, when we write after running or violent exercise, certain unusual flourishes appear which make the characters unrecognisable.

I have noticed a curious tremor during inspiration in suffering men and animals. I have found it in a less degree also in healthy animals, particularly in dogs. At every inspiration there is a very noticeable tremor of the limbs and of nearly the whole muscular system. The excitement arising in the nerve-centres to produce a contraction of the diaphragm and of the muscles of the thorax seems to have become so strong, that it goes beyond the limits of the respiratory centre and diffuses itself over a great part of the nerves. In anger, fear, and mental perturbations, when the stormy winds of passion rage, waves flow to all parts of the nervous system, then break, revealing themselves in the agitation of the muscles.

Trembling often has a peripheral origin, and may be due to both heat and cold. It is sufficient to hold the arm in water heated up to 48° or 50° in order to produce a visible tremor. This fact, which I observed repeatedly on my brother, corresponds to the chattering of the teeth when a cold stream of air strikes our face.

V

Very excitable dogs often tremble when another dog approaches. I know one that trembles like a leaf whenever, from the height of a second floor, he sees a bigger dog passing in the street. This lively alarm is quite pitiable, and after all most unnecessary, for the most of his supposed rivals do not perceive his presence, nor even look up. But as soon as he catches sight of them in the distance, he becomes suspicious, a feverish shiver goes over him, the hair on his back stands on end, his whole body trembles, while he cowers near the window with ears erect, looking fiercely out of the corners of his eyes, snarling, and showing his teeth—a ridiculous instance of timid arrogance and despised pride.

But most clearly does trembling become manifest during fear. As army surgeon, I had once to be present at the execution of some brigands. It was a summary judgment. A major of the bersaglieri put a few questions to one or two, then turning to the captain said simply: 'Shoot them.’ Some were dumb-founded and stood open-mouthed, petrified; others seemed indifferent. I remember one lad, of scarcely twenty years of age, who mumbled replies to a few questions, then remained silent, in the position of a man warding off a fatal blow, with lifted arms, extended palms, the neck drawn between the shoulders, the head held sideways, the body bent and drawn backwards. When he heard the dreadful word, he emitted a shrill, heart-rending cry of despair, looked around him, as though eagerly seeking something, then turned to flee and rushed with outspread arms against a wall of the court, writhing, and scratching it as though trying to force an entrance between the stones, like a polype clinging to a rock. After a few screams and contortions, he suddenly sank to the ground, powerless and helpless, like a log. He was pale and trembled as I have never seen anyone tremble since; it seemed as though the muscles had been turned to a jelly which was shaken in all directions.

Even in their minor degrees apprehension and fear make us tremble. When hurried one cannot perform any minute work, the convulsive fingers can grasp nothing. I know timid girls who are ashamed of the trembling of their hands when filling the tea-cups of their guests.

A gentleman in Germany told me some very curious things about his excitability, amongst others that he had had to give up dancing, as his legs left him in the lurch at the least emotion. Everything disturbed his equanimity; if he had to offer his arm to a lady to take her in to dinner, or to walk across the room when in company, the mere thought of being observed made him tremble and totter as though intoxicated.

The kneeling attitude which one finds amongst all people as a sign of adoration, love, and as the position of one imploring pardon or mercy, must be ascribed to the physiological fact that strong emotions cause a sudden trembling of the legs and oblige us to sink to the ground.

VI

In thinking over the question of trembling, memory has become so excited, that wherever I seek a place of repose amongst my recollections, I still see people before me, trembling. The first, dimmest of these recollections is of an old uncle of mine, a veteran, who, while I was a child, used to take me on his knee to tell me about Napoleon’s battles, and I would look at his snuff-box shaking in his hands and could not understand why I must help him to steady his fingers, as he showed me the picture of the emperor on his medal. And behind him I see a simple, affectionate old lady who used to say tender words to me with her trembling voice. She was the godmother of my mother, and was always so indulgent with me when I played near her little work-table, and used to watch me contentedly over her spectacles, waiting till I had drawn the thread through the big-eyed needle, and telling me that her hands no longer obeyed her.

Then the trembling fit which came over me in the Alps when I had wandered through a glacier, risking my life at every step, and it seemed a miracle that I should have escaped the dreadful abyss which was ready to engulf me. Again, amongst the first recollections of my hospital life, I see the emaciated faces of trembling invalids poisoned with quinine or mercury; the convalescent, sitting up in bed, unable to steady the cup in their hand; the anÆmic, who, from loss of blood, performed every movement tremblingly; the ravingly hysterical, who only found rest in sleep.

I recall again the times and places when I have hurried excitedly to fires, boiler-explosions, to the ruins of fallen buildings, and have seen men whose teeth chattered in consequence of burns received, strong workmen laid on stretchers who trembled from the effect of their contusions. I remember the night-watches, when we used to relieve each other in attendance on those unfortunate beings who had fallen a prey to tetanus, and whose life had to be prolonged by inhalations of chloroform. In the long, silent halls of the infirmaries I still see the pitiable look of those suffering from tabes dorsalis or paralysis agitans, who could not stand steadily, nor indeed erect themselves at all, as though a curse were agitating the muscles, over which the will had lost all control, and which at last became so rigid that even the bones of the skeleton were bent and deformed.

But let me turn away from these recollections of misery, now when I see crowding before me more cheerful pictures—of that solemn tremor with which I have seen parents overcome, who, at the wedding of their children, could no longer hold the glass in their hands, and stammered unintelligible words with tears in their eyes. I see young poets, too, who cannot steady the paper as they rise to read their verses to a merry company; and busy housewives with trembling lips, and faces beaming with satisfaction, who have to sit down because they cannot subdue their exultation at their success; and lastly, relatives who, with convulsive hands, embrace each other in the joy of meeting once more.

I have known men so nervous that they had to retire at the slightest emotion, lest they should betray an agitation which seemed ridiculous to them; and I have seen others support themselves with a hand on a table or chair that they might not tremble when they heard a moving speech or saw the representation of a tragedy at the theatre.

I remember onanists who, from fear of their trembling-fits, have been reduced to the humiliation of confessing their loathsome, degrading vice; love-sick friends who have been startled at the trembling of their hands, which altered the character of their writing; colleagues who have consulted me on account of a trembling which appeared after they were exhausted by mental work; and persons who, in consequence of a fright, were subject to trembling for the rest of their lives.

VII

But it is in delirium tremens that fear and trembling together form the most awful torture, the most horrible punishment of human nature. During my life as a physician I have only seen three such cases, and the faces of the wretches float before me, covered, as it were, with a veil of profound melancholy.

I shall condense the observations which I made into a single picture, so as not to detain the reader too long amongst such scenes of misery.

Generally, one is called in haste to a patient who is vomiting, or who is thought to be seized with insanity. One finds a wan, emaciated man, who looks at us indifferently, or answers with a few impolite words in a dull, rough voice. Relatives, wife and children, who stand frightened around the bed, tell us that he has been immoderate in drinking, and had been brought home intoxicated the night before; that he had grumbled the whole night long, and did not rise in the morning because of excessive fatigue; that he had felt sick all day and had had no appetite, and that he had then begun to vomit. When he shows his tongue, we see that it is covered with a thick, whitish coat, as in catarrh of the stomach.

In the first period of the illness, the hands do not tremble as they lie on the coverlet, but when the patient tries to take a cup or a spoon, they shake so that everything is upset and spilt. At night the dreams, which have already awakened him in fright, assume the character of a positive hallucination. Often patients spring out of bed, crying that a snake is twining round their neck, and they tear, panting, the clothes from their body, and wander about naked, writhing, as though trying to release their neck from a noose, to free themselves from fetters in which their madness has bound them fast.

Then they grow quiet again, but the delirium has broken out and will develop, leaving them no more peace. They will lend life to every shadow, and see perpetually before them reptiles and insects crawling about and multiplying. What agony! Ever and anon they cry out that monstrous spiders or venomous scorpions are creeping from the walls on to the bed; that black cats with fiery eyes are crouching on their breast; that wolves with open jaws or mad dogs with foaming mouths are biting them, or that loathsome rats, mingling with a black swarm of beetles, are gnawing at their vitals. And then the patients, tortured, annihilated by fear, writhe, gnashing their teeth, groaning, howling, sobbing. They bite their hands, tear the bed-clothes, bury their nails in their faces disfigured with rage. Then they rise to escape, and fall heavily backwards into bed, exhausted, pallid, with distorted face, a rattling in the throat, and their eyes rolling in the most awful despair.

Sometimes this hideous storm blows over, and a little calm returns. The patients are languid, and when questioned answer intelligibly but crossly. In lucid intervals some regret their faults, and say that they drank in order to forget their misfortunes or their misery, but these are only rays of light in the midst of ruins shrouded in darkness. Nearly all remain indifferent to the desolation of the family, shake their heads disconsolately, and talk of suicide. At every feverish attack, by whatever cause produced, the frenzy becomes so great that they must be bound and secured in a strait-jacket.

The trembling increases, the patient cannot sleep; he chatters, walks up and down, wandering about the room like a lost dog. We make out from his laments that the hallucination is gradually taking possession of all his senses. In stammering, disconnected words, he complains from time to time that he is poisoned, has the taste of something loathsome in his mouth, and he rejects everything because he fears treachery. He says there are chemical vapours rising in the room which will suffocate him, and then he runs hither and thither raging, fighting the air with clenched hands, pressing himself close to the wall, or rushing to the window, throwing to the ground furniture and utensils from which he thinks he sees the pestilential vapours poured forth.

My whole life long I shall remember with a shudder the night which, as a student, I spent with one of these unhappy wretches. It was at that time when physicians believed that the danger could be averted and the delirium shortened by a speedy letting of blood. I had been sent by an old physician into a squalid garret, in order to bleed a patient. I found him in bed raging violently. He was a sturdy porter, with inflamed face and swollen neck-veins. When I tried to take him by the arm, he looked at me with bloodshot eyes that seemed to devour me. Then he began to mumble and tremble, pouring forth oaths like stormy thunder, and howling like a lost soul. 'No, no, help! Stop the murderer who is going to kill me—he has a razor to cut my throat!’ His face wore a terrible expression of fear, the furrows on the brow, the dilated nostrils, contracted lips, the gnashing of the teeth, gave evidence of a desperate struggle. Then he writhed in our arms, trying to escape, while we held him back. 'Help!’ he screamed, 'they are going to throw me out of the window, on to the bayonets below! Help, quick, take those cut-throats away! Do you not see that the street is full of soldiers and executioners, who are climbing up on ladders to stab me?’ Until at last, worn out, bathed in perspiration, livid, breathless, still cursing and murmuring, he fell gradually into the lethargy of the dying.

When the disease grows worse, the delirium becomes continual, the trembling increases, the muscles swell to such a degree that it seems as though they would burst. One might almost think that a furious demon were hidden within, agitating the body in the bed, distorting it, hurling it to and fro, as though to shatter it completely. The most terrible apparitions are those of spectres. Some of these are so horrible that the patients are paralysed with dread. They suddenly send forth a terrible shriek, hold their hands in front of them, throw the head back, but still think they see the lean and colourless face of some dead man whom they call by name. Disguised enemies with fleshless countenance, wrapped in grave-clothes, come to lead them away with them; skeletons stride through the room, rattling their bones and gnashing their teeth with devilish glances.

Then Death, dressed in all the horrors of the most corrupt reality, appears to lower them into the grave. 'Take away this rotting corpse which those wretches have put into my bed! Do you not see that it is a liquid, loathsome mass, a putrefied abomination, and that the worms are crawling about the body?’ And they hold their nose to exclude the putrid smell, and look at their hands, on which they see clots of blood, livid streaks, and the revolting blackness of gangrene. Sometimes all ends suddenly, but often they sleep after the delirium has lasted three or four days, and on waking, fall into imbecility, die exhausted, or else become quite mad.