_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]
[15] Haller: _Elementa physiologiæ corporis humani_, tom. v., lib.
xvii. § vii.
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.
[16] Darwin, chap. iii., p. 67.
[17] Mantegazza, chap. vii., p. 119.
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.