EV. It is evident, as in dreams, and in rare cases of disease, that the
mind of the somnambulist is often a contrast to its waking faculty. The
memory will leap over intervals. Dr. Dyce records an illustration of
this. A girl, _in a state of somnambulism_, was taken to church, and
wept at the subject of the sermon. She never adverted to this impression
when she awoke; nor could she be brought to recollect it until, in her
_next sleeping paroxysm_, she spoke of it distinctly.
In delirium, also, we see these intervals of thought. The patient will
commence a subject in the delirious state; when this has subsided, the
subject is dropped. In the _next attack_ of delirium it will again be
started, ay, and at the very point, even _the word itself_, at which it
was broken off.
We read, in an American journal, that a man, previous to an attack of
mania which lasted _several years_, had placed his work tools in the
hollow of a tree. To them no allusion was made during the period of his
disorder. When, however, this passed off, he directed his son to fetch
them, believing that he left them _only yesterday_.
In the same book, too, we learn of that lady who became maniacal as she
was engaged in needle-work. For seven years she thought not of this; but
directly she recovered, she asked for her needle-work and canvass. The
same may occur in intoxication also, which _is_ but another form of
delirium. In Mr. Combe’s work we are told of a drunken man who left a
parcel at a wrong house. When _sober_, he recollected nothing of the
circumstance; but when _again intoxicated_, he soon remembered his
error, and reclaimed the parcel.
ASTR. These cases form high contrasts with Hamlet’s proof of insanity:
——“Bring me to the test,
And I the matter will reword, which madness
Wou’d gambol from.”
EV. Yet if you analyze their nature you will find them even _proofs_ of
derangement; for you thus see that the faculty of memory is changed
according to the state of mind. In the following case, by Dr.
Abercrombie, we shall find the same variation in impression and taste. A
girl, in her early youth, expressed her abhorrence of tunes played on
the violin, which she termed a _discordant fiddle_. She was after this
introduced into more refined society, and became a somnambulist. During
her paroxysm she imitated the _beautiful airs_ which she said she had
formerly heard on this same violin.
Lieutenant C—— was once my patient, and died a maniac. The insanity
arose from thwarted ambition, and was confirmed by his notion that he
had seen his death-fetch. For some time he walked and talked in his
sleep; subsequently he would walk for an hour round the table
unconsciously. In him, too, was this change of feeling. He once talked
little, and cared less for his child; but now he would caress it fondly,
and expressed the deepest anxiety for it. It was difficult to decide, at
times, whether this gentleman was awake or not; indeed, these states of
mania, which have been termed “melancholia errabunda” by Bellini and
Montalti, are closely allied to somnambulism, for the walker is absorbed
in deep thought, and totally unconscious of his actions. And the analogy
appears to have been recognised by the law. It is well known that the
brother of Lord Colepeper, who was a great dreamer and somnambulist,
shot a guardsman and his horse. He was found guilty; but he was pardoned
on the ground of his complete _unconsciousness_ in his somnambulism.
We do not wonder more to see the perfection with which these unconscious
labours of the somnambulist are performed, than at the ease and power
which is evinced, and the very slight fatigue which ensues; although the
occupation might have been most laborious.
As in _chorea_ the most delicate girls will dance incessantly for
twenty-four hours, resting merely for one sole hour; and yet they will
sit down perfectly cool and free from fatigue.
IDA. Is it not wonderful that the somnambulist will incur great dangers
with complete _sang-froid_? They will walk over
——“Torrents roaring loud,
On the unsteadfast footing of a spear;”
or scale the gigantic precipice, the mere contemplation of which would
fright their mind from its propriety, when awake. I remember to have
read of a French Jew, who walked by chance across a dangerous pass over
a brook, _in the dark_, without the slightest fear or harm. The next
day, perceiving what danger he had incurred, he fell down dead.
EV. It is equally curious that a concentration of nervous energy, which
is here the result of unconsciousness, should also be produced _by_ fear
in some cases, which, in others, _paralyses_; but this is indeed a
slight degree of heroism, or energy of despair. Thus we leap far higher,
and run much faster, when danger threatens, than we could believe.
These are all very apt illustrations of somnambulism. I will check
myself in quotations of more, as the phenomena may closely resemble each
other.
But what is its philosophy, and how can I venture on its explanation,
which involves the most intricate pathology of the nervous system?
unless, with the self-complacency of quaint old Burton, I cut the
Gordian knot by this affirmation,—“There is nothing offends but a
concourse of bad humours, which trouble the phantasy. These vapours move
the phantasy, the phantasy the appetite, which, moving the animal
spirits, causeth the body to walk up and down, as if it were awake.”
Thus much I may expound to you, if I am again allowed to run up our
scientific scale. The philosophy of the dream and of incubus refers to
the activity of the brain with a _passive_ body; for somnambulism, we
require an _active_ body, with an _unconscious_ brain.
Now there are _four_ sources of nervous influence:—the brain and
_cerebellum_, within the skull; the marrow in the spinal canal; and the
nervous bundles in the large cavities, termed _ganglia_.
It is on the independent or unconscious function of the marrow, chiefly,
that those mysterious actions, which do not seem to be willed by a
conscious mind, depend.
In the day-dream, a thought or form shall present itself, even at a time
when the mind is employed on subjects of a contrasted nature. These
thoughts, or forms, are usually fraught with a high degree of pleasure
or of pain, or refer to events of vital importance, to the
dreamer;—such are the objects of the lover’s idolatry, the anticipation
of misfortune, or subjects of prospective felicity. Under this
excitement, the influence of external objects is often for a time lost;
the _retina_ may be struck by a ray, or the _membrana tympani_ by a
vibration, but the mind shall fail in its perception,—no _internal_
impression being made. This cannot arise from a point of the _retina_,
or the expansion of the auditory nerve being pre-occupied, as some have
supposed. The idea of material impression must fail in explanation; for,
on the instant that the mind is awakened, the external impression is
again perceived. The external sense, in this case, is not in fault; nor
is its direct influence on the _sensorium_ suspended; for we find that a
person will continue to read in this state, as it were _mechanically_;
but the attention is _diverted_ by deep thought, so that the reader, at
the end of his task, may have no remembrance of what he has been
reading.
Let me tell of a curious little episode of Dr. Darwin’s, which will aid
me in my illustration. A young lady was playing on the piano a very
elaborate piece of music. It was correctly and scientifically performed,
although she was agitated during her task; and when it was over, the
lady burst into tears. She had been watching all the time a favourite
canary in the fluttering of death; and with this catastrophe her _mind_
was almost wholly occupied, but her _fingers_ did not err in their
complicated and delicate motions, which they undoubtedly would have
done, if the will or mind alone had directed them.
In sanity of mind, and in mania, the most philosophical distinction is
based on the _health_ or _disease_ of memory. The ecstacy of madness may
not seem perhaps more irrational than an ecstatic vision, but the maniac
will not re-word the matter; whereas the mere visionary will repeat the
action of the trance as a dream.
ASTR. But there is a sort of somnambulism the reverse of this. In the
retreat to Corunna, many of the soldiers, although exhausted by a long
march, and having actually fallen asleep, continued to move forwards,
leaving their companions behind, who halted and laid down to repose.
EV. This is the _continued association_ of that excitement which has
produced muscular motion. The mind was exhausted and sleepy, the brain
was inert; but we believe that the spinal marrow does, of itself, effect
motion, while the will and consciousness sleep; and we may also _stand_
and sleep. These soldiers did not walk in their sleep, but slept in
their walk.
ASTR. I am informed, too, that Richard Turpin, in allusion to his famous
flight to York, asserted that Black Bess appeared to gallop
unconsciously.
EV. It is true; and when we reflect on this gigantic feat, we may
suppose that the mare gallopped the farther, because her _consciousness
of fatigue was not awake_, and her muscular energy was thus
concentrated.
Paralyzed muscles will often quiver when the sound limb is quiet; the
brain’s influence being, in this case too, inert, sensation is
diminished; but _involuntary_ motion continues from a habit in the
muscle, or the excitement of unexhausted irritability, as in _chorea_,
spasm, &c. And in some cases of _post mortem_ galvanism, Dr. Dunbar, of
Virginia, passed the _galvanic aura_ along the _ulnar_ nerve of an
executed negro, and the fingers instantly quivered, and assumed the
attitude and action of one playing on a flute or the strings of a
violin.
ASTR. It is possible, then, to move without our _willing_ to do so, or
being conscious of our act.
EV. There are believed to be, indeed it is almost a
demonstration,—_four sets of nerves_, traced along the spinal marrow.
Two to the brain, of _sensation_ and _volition_, by which the mind feels
what the body touches, and transmits its will to the muscles; two others
to the marrow, by which _it_ also is stimulated by outward touch, and by
which _it_ excites the muscles to motion.
Now when the brain’s influence is kept from muscle, that muscle will
still possess _irritability_, derived from the spinal marrow; nay, that
irritability will be greater, _because it has not been expended_ by the
acts of that volition, which resides solely in the brain, and which is
now cut off. Thus the _excito-motory_ function, and the influence of
volition, are in these cases _antagonists_. And this principle of the
_incident_ and _reflex spinal_ nerve is an explanation of the curious
dilemma, regarding the suspension of the will in sleep and dream, to
which Dr. Stewart alludes.—“Not a suspension of volition, but only of
_its influence_ over those organs, which it moves when we are awake.”
Decide for yourselves between the physical and metaphysical theories.
Yet, do you not see that all this does not essentially require the
direction of mind? If you tickle the palm of a sleeping child, it will
close its hand upon your finger; if you awake it, and _engage its
attention, it will often leave its hold_. This is a fact proved by the
_anencephalous_ or brainless children. Even the puppy, deprived of its
brain, and also the _mammary fœtuses_ of the kangaroo and opossum, fix
eagerly on the nipple when it touches their lips. There is a beautiful
mechanism in the foot of the roosting birds, adapted to this
physiological law. The tendon of the claws is tightened immediately they
are touched, by which action they contrive to grasp the bough or perch
even when asleep. In cases of _paralysis_ even, the foot will sometimes
be instantly drawn up, although it does not possess the least sensation;
we may assert, then, that irritability is in an _inverse ratio_ to
sensibility.
The _polype_, in which we trace no brain or nerve, exists and moves by
its irritability, and without sensation or consciousness. We know also
that the _vis insita_, or _vis nervosa_ of a muscle, that is, its
irritability, exists even after the animal life has ceased. The turtle
will live and move long after its brain has been removed. The heart
itself, an involuntary muscle, is stimulated also to action without
sensation. The heart of the assassin, Bellingham, beat long after he was
cut from the gallows.
If I have made these things clear, I am now prepared to explain, with
some anticipation, those two curious contrasts, somnambulism and
incubus. If the spinal or motive nerves be asleep, and the cerebral or
intellectual, or volition nerves, awake, we shall have night-mare; if,
on the contrary, the motive nerves are in excess, beyond the sensiferous
or volition nerves, we have sleep-walking.
ASTR. I believe the philosophy of Leibnitz affirms _two_ perceptions;
one with, and another without, consciousness. I do not recollect if he
distinguishes the _seat_ of these _perceptions_; but, if the brain be
that which perceives, I presume consciousness will follow that
perception sometimes in so slight a degree as not to excite judgment or
reflection. Am I correct?
EV. You have adopted the common error of metaphysicians. If, in the
abstraction of waking moments, some persons talk to themselves, as it
were unconsciously, so, from the _reflex_ influence, may volition and
motion occur, with as little self-feeling. That the _immediate_
impression, however, and a necessity of action, may combine, is
illustrated by Dr. Beattie’s case of the officer who could be thus
excited in his sleep. By a whisper in his ear, he was induced to go
through the whole ceremony of a duel, and did not completely wake until
the report of his pistol roused him. This gentleman was also told that
he had fallen overboard, and he began to imitate the motions of
swimming; then that a shark was following him, when he would dive off
his couch upon the floor; and when he was told that the battle was
raging around him, he proved himself an arrant coward by running away.
Somnambulism may be induced by congestion or irritation of _that point_
where the _incident_ nerve blends with the _grey matter_ of the spinal
marrow, producing internal irritation, as the tickling of the foot does
through the _cutaneous_ nerves of a senseless limb.
CAST. We are thankless creatures, dear Evelyn, but all this reiteration
bewilders me, does it not you, Ida? Yet, in my simplicity, I can but
think it unphilosophical entirely to disregard the _will_ as the spring
of our actions.
EV. If I must EXPLAIN, fair lady, I cannot avoid prolixity. But to your
question I will answer, no; for somnambulism _may be excited_ by the
_memory of an intention_. In the experiment made by the committee of the
physical society of Lausanne, on the Sieur Devaud, of Vevay, it was
proved that on the evening before the fit of somnambulism, his head was
heavy, and he had a sense of oppression on his eye-lids. If, at this
time, the mind was impressed by some legend, or story, or incident, the
actions of the sleep-walk were perfectly _coincident with such a
subject_. If a romantic tale of banditti were related, his alarm would
be apparent in his subsequent sleep. In this somnambulist was
beautifully illustrated the effect of permanent impression on the brain,
rendering, for a time, the sense of vision useless; for having once
perused his paper, it was so imprinted on his mind, that the _exact_
spot for each letter was _exactly_ fixed on _by the finger_. And we have
heard of one more interesting case, in which the somnambule, remembering
that he had made errors in his writing, traced, on a blank paper
substituted for that written on, the corrections, _in the very places
corresponding to the erroneous writing_. And that here was memory was
proved in this, that during the time his eyes were shut, the pen was
dropped on the _very spot_ where the inkstand stood; but this being
removed, no ink was obtained, and the writing was blank.
Now we believe that there are certain vessels which contribute to
nervous energy, perhaps by secreting a nervous fluid in the brain, or by
concentrating electricity, which Dr. Faraday believes may constitute the
_animal_ portion of the nervous system. This influence may be profusely
accumulated in a waking state; the resolution to act has been formed;
or, there may be a rapid production in sleep of this energy. Then, when
sleep occurs, _this impression becomes uncontrolled_. The third form of
insanity of Spurzheim, irresistibility, exists, and the night-walk takes
place. And indeed it may form an interesting analogy to that satiety of
the voluptuary, “Childe Harold,”
“Who e’en for change of scene wou’d seek the shades below,”
and to one unhallowed story related in “Salmonia.”
From this excess there is the stimulus of _pain to move_; one of the
most powerful motives of human action. Cardan, if we may believe in his
“Opera et Vita,” was at least a monomaniac; and he “was wont
instinctively, as it were, to relieve this tendency of his mind by the
excitement of bodily pain.” I may assure you that I have, during my
professional studies, often witnessed (and indeed have sometimes
suggested) a remedy on this knowledge: you may be aware, that a severe
and painful disorder will mitigate, if not entirely dissipate, that
apathetic misery which springs from a vacant or unoccupied mind.
In contrasting childhood and age, we witness these curiosities in the
restless activity of youth and early manhood, for at these periods we
are very constant somnambulists; not so in the passive state of old age,
in which sleep-walking is very rare. Something of this we see also in
the _growing pains_ and _fidgets_ of girls and those whose duties are
sedentary. Exercise is the relief for all this.
Now when the sleep-walk has exhausted this excess of irritability or
electricity (if it be so), the dreamer returns to bed and sleep. A hint
is here thrown out to us, that if powerful exertion be employed previous
to sleep, the night-walk might not ensue. Lethargy often terminates in
somnambulism.
If I may for another moment still prose over the intricate, but deeply
interesting question of the pathology of somnambulism, I will observe,
that we often find it one symptom of madness or idiocy, and we know that
somnambulism not seldom terminates in epilepsy.
In the brains of epileptic idiots, who are very determined
somnambulists, we discover changes the most various; _effusion_,
_congestion_, _ossification of membranes_, _ramollissement_,
_indurcissement_, bony _spiculæ_, or points pressing the brain,
_tubercles_, _cysts_. In some, the skull assumes the density of ivory.
Yet in those persons who have been known to be sleep-walkers, the
inspection is seldom satisfactory. _Plethora_ of the head has often,
however, preceded the sleep-walk. Signor Pozzi, physician to Benedict
XIV., if he submitted not to depletion each second month, became a
somnambulist; and we have known that in _chorea, previous to the dance_,
and in some cases of somnambulism also, pain has been felt from the
_occiput_ along the course of the _spinal marrow_. This is from
immediate excitement; but _dyspepsia_ and other _abdominal derangements_
may so influence the _ganglia_ and _nerves of organic life_, and through
them the brain and cord, as to excite sleep-walking by _remote_
sympathy.
That injuries of the nervous matter about the nape of the neck are of
the highest importance in our studies of these eccentric actions, is
certain. The experiments of Flourens show that the _progressive_ or
_forward_ motion of animals, is influenced by varied states of the
_cerebellum_. When Majendie cut through the _corpora striata_, the
animal darted forward; when the _pons Varolii_ was cut, the animal
rolled over sixty times in a minute.
When a soldier is struck by a ball about the _cervical vertebræ_, he
often springs from the ground and drops dead.
It is our duty, then, not to slight the condition of the somnambulist.
If _simple irritation_ be its exciting cause, much benefit may be
derived from _counter-action_ on the surface, and other remedial means.
Even if there be _diseased structure_, some palliation may be afforded.
As preventives of the fit, we may inculcate an abstinence from late
meals, exercise in the evening previous to retirement to rest, a high
pillow, &c.
If the propensity continue in spite of our efforts, it will be right to
have the windows fastened or locked, and the door of the chamber bolted
_without_; or to confine the ankle or wrist to the bed-post by a long
fillet, which may by its detention awake the sleeper on starting from
the bed.