Bauhaus-Universität Weimar

810 
SLEEP.—ITS PHENOMENA. 
oro-ans of animal life are rendered capable of renewed action by the operations of the 
organising force, which proceed without the consciousness of the animal, though ac¬ 
cordant with a well-contrived plan and with reason. 
In consequence of all parts of the organism participating to a certain extent in the 
states of excitement which affect primarily only one part, the waking of the system of 
animal life, and its consequent increased excitement, must be gradually imparted to 
those organs which are under the influence of the organic nervous system; and any 
functions which these organs may perform, in addition to thamere process of organisa¬ 
tion, will be in some measure affected. Hence it is that the heart’s action becomes 
rather more frequent at the time of waking than it was during sleep. The radiation 
or extension of excitement from the animal system to the organic ceases during sleep, 
and so far the organic part of the body has at that time a remission of action, though 
in a less degree than the animal system. If the waking state of the animal system is 
maintained much longer than natural, this extension of excitement from it to the or¬ 
ganic system not merely becomes more manifest, (for instance, in the acceleration of 
the heart’s action,) but the great exhaustion of the organised material by continued 
action is imperfectly balanced by the organising process. Hence the signs of defective 
nutrition, which soon show themselves when watching is long protracted. 
Having considered thus far the nature of sleep generally, we will now study more 
minutely its phenomena. On the commencement of sleep the senses cease to per¬ 
ceive external impressions, and the play of ideas, and the emotions, are entirely or in 
greater part silenced. The will ceases to rule the muscles; the eyelids, which ex¬ 
perience the sensation of fatigue, are no longer under command; the head droops, and 
this state of inaction soon extends over the whole animal system of organs. 
When sleep is perfect there is generally a complete absence of voluntary motion; 
while the involuntary movements of the organic muscles, and those movements of 
certain animal muscles which are only in part under the influence of the will, such as 
the respiratory movements, continue; the movements last-mentioned merely ceasing to 
be influenced by volition. The movements of the heart, and the respiratory movements, 
are somewhat less frequent than in the waking state. The action of some animal 
muscles is increased during sleep, they being apparently released from some counter¬ 
acting force which opposed them in the waking state. Such is the case with some 
of the muscles of the eyes, as well as with the muscles of the extremities in birds 
which sleep standing on one or both legs. During sleep the eyes have a peculiar 
position. At that time, as well as in a state of mere sleepiness, both eyes are turned 
inwards and upwards. This movement is still more strongly displayed in disorders 
of the nervous system; for example, in epilepsy and catalepsy. This position of the 
eye during sleep also gives it a very different expression from that which it has in 
death. The iris is contracted in a person asleep, and the pupil consequently nar¬ 
rowed; but on his awakening the pupil always dilates, becoming first, indeed, very 
wide, and then undulating, until it acquires the mean size which it has in the waking 
state. (See page 535.) A greater amount of external warmth is required for the 
body during sleep than at other times; and immediately after the awakening from 
sleep there is frequently great sensibility to cold. 
W;hen, during sleep, the conception of ideas by the mind does not entirely cease, 
dreams arise. These are for the most part composed of simple ideas and emotions; 
but general notions sometimes come into play, and movements affected by the animal 
muscles may be combined with the ideas as in the waking state. This condition of 
the mind is “dreaming,” as long as the sensorium is disturbed by something which 
gives to the operations of the mind a character opposed to that of the ordinary con¬ 
ceptions and thoughts of the same person. The ideas conceived in dreams so far re¬ 
semble those of the waking state, that they may refer to any period of the past life; 
just as in our ordinary condition we may look back to all periods of our life, and think 
at one moment of yesterday, and the next of times years past. If the ideas which 
occupy the mind during the waking state have a certain degree of persistence, the 
same ideas will recur in dreams during sleep. The dreams of some persons, on the 
other hand, refer chiefly to times long past. Many blind people, after they have been 
some time deprived of sight, cease to dream of visible objects, but their dreams 
accord with their present mode of intercourse with the external world. Other indivi¬ 
duals, who have lost their sight, continue through their whole life to dream of visible 
objects. The important circumstance, therefore, regulating these dreams of visible
        

Nutzerhinweis

Sehr geehrte Benutzer,

aufgrund der aktuellen Entwicklungen in der Webtechnologie, die im Goobi viewer verwendet wird, unterstützt die Software den von Ihnen verwendeten Browser nicht mehr.

Bitte benutzen Sie einen der folgenden Browser, um diese Seite korrekt darstellen zu können.

Vielen Dank für Ihr Verständnis.