The reason why : $b a careful collection of many hundreds of reasons for things which, though generally believed, are imperfectly understood. A book of condensed scientific knowledge for the million — John Stuart Mill — John Shaqi
The reason why : $b a careful collection of many hundreds of reasons for things which, though generally believed, are imperfectly understood. A book of condensed scientific knowledge for the million
John Stuart Mill · en
But when sleep overtakes the system, it seems as if the _relations_ of
those parts under the controul of the will were temporarily suspended;
as if, for instance, those nerves which move the arms, the legs, the
eyes, the tongue, &c., were all at once unfastened, just as the strings
of an instrument are relaxed by the turning of a key, or the throwing
down of a bridge over which they were stretched.
What is meant by the temporary suspension of the relation of the
brain to some parts of the body, may be thus explained. Notice
a man when he sits dosing in a chair: at first his head is held
up, the brain controlling the muscles of the neck, and keeping
the head erect. But drowsiness comes on, the brain begins to
withdraw its influence, and the muscles of the neck becoming as
it were "unstrung," the head drops down upon the breast. But the
sleep is unsound, and disturbed by surrounding noises. The brain
is therefore frequently excited to return its influence to the
muscles, and draw up the head of the sleeper. He gives a sudden
start, every muscle is tightened in an instant, up goes the head,
the eyes open, the ears listen, until a feeling of security
and composure returns; the sleep again deepens, _the nervous
connection is again withdrawn_, and then down drops the head as
before.
[Verse: "Yet a little sleep, a little slumber, a little folding of
the hands to sleep: So shall thy poverty come as one that travelleth;
and thy want as an armed man."--PROVERBS XXV.]
1020. _Why do we dream?_
Dreams appear to arise _from the excitement of the brain during those
hours when its connection with the other parts of the living organism
is suspended_. For instance: a man dreams that he is pursued by a
furious animal, and the mind passes through all the excitement of
flying from danger; but the _connection_ between the moving power, and
the machinery of motion being suspended, no motion takes place. The
same impressions upon the brain, when the nerves were "strung" to the
muscles, would have caused a rapid flight, and a vigorous effort to
escape from the apprehended danger.
1021. _Why do suppers, when indigestible substances are eaten, produce
dreaming?_
Probably because, as the digestive organs are oppressed, and those
parts of the nervous system which stimulate the organs of digestion are
_excited by excessive action_, those portions of the brain which are
not immediately employed by the digestive process are disturbed by that
_sympathy_ which is observed to prevail between the relative parts and
functions of the body.
1022. _Why do we yawn?_