Evening star., 1886-11-06
The Science of Sleeu.

THE SENSES THAT FIRST LOSE CONSCIOUSNESS
IN sLUMBER-soME INTERESTING FACTS.
From the British Medical Journal
Each successive graduation in sleep is marked
by the inclusion Of a nervous system, which is
for the time being shut off, SO to speak. from
participating in the general life-functiOn of the
individual until, when the maximum intensity
Is attined n3thlng , Is lett put the purely anil
Sleep OF this degree Of intensity, although a
perfectly normal process, is not, in health of
long duration. Alter the lapse of q variable
space OF time, the systems one by one resume
their functions, until finally the sum OF per-
ceptions brings about the condition OF awaken
ing.
The brain shares in the need, which is every.
where apparent, of periods Of rest. The pro-
ducts OF cerebral activity accumulate more
rapidly than they ere eliminated, aud a period
therefore arrives when the tissues are no longer
able to do their work. The result Is an invin-
Cal or mental. The temporary and invoiun-
tary cessation of activity Is at once followed bv
adiminution of the blood supply; the an@mia
SO induced being, therefore, a consequences aud
not cause, of the state OF repose.
The various parts OF the nervous system are
not all involved simultaneously or to the same
extent The centers governing voluntary
movement are the first TO be affected as seen
in the nOdding OF the head and the closure of the
to assume the position OF repose determined by
the laws of gravity. The special senses soon
follow, but here, here again they are not abrogated
no longer reaching that portion OF the cere-
brum where 1t can give rise to a definite sem
sauiOn, even where the closure of the lids has
not shut off xternal stimuli altogether. Hear
ing and smell are remarkably persistent, and
except in The deepest sleep, may be said to be
only duled, and not extinguished. Every one
Ia familiar with the ease with which sleep Is
put an end 70 by unaccustomed noise even OF
slignt intensity or. better still, by the cessa-
tion OF any monotonous sound, as, for In.
stance, the awakening OF travellers by rail
or steamboat on any stOppage Of the train
or machinery. Instances are on record. toO
where the inhabitants OF the house have been
reused Simply by the smell OF tobacco, in
ouiged In by inexperienced or incautious
burglars The persistent sensibility Of these
senses may, to some extent, be accounted for
by the TACT that they are not shut OF from COM
munication with the outside world as are. for
example, the eyes. To allow sleep, or at any
rate quiet sleep, q certain harmony must exist
in the condition of all the organs, which must
so to speak, be tuned TO the sleep tone. II
one organ be In u state OF activity, Or ON the
other hand, its condition be abnormal In some
other way, the sensOrium refuses to abdicate
It's control This s familiar 70 Us in the case of
cerebral activity or cold feet 1T bed time, both
| being iniinical 10 sleep. Inasmuch, therefore,
as insomnia ma, result from either Sc or
causes we can either employ drugs, such as
opium, which act directly on the nerves-centers
and SO bring about sleep; or We may resort to
medicines like hypnone, which is said 70 favor
sleep rather than induce It by aliaying the ir-
ritable or hyper@sthetic condition OF certain
organs or parts.