The Charleston daily news. [volume] (Charleston, S.C.) 1865-1873, 1872-11-02
BRAIN CIRCULATION DURING szEkP.

The relations existing between the phenom-
ena OF circulation in the brain and the func-
tional activity of that organ have long re-
manned obscure, owing to mistaken Ideas Of
the conditions Of sleep, winch ID rightly con-
sidered the state Of rest Of the cerebral organ.
The ancIents supposed that sleep resnited from
compression e4erted on the brain by the
blood when Its circulation declined. They
imagined that this pressure was chiefly ex.
erted ut the back part OF thu head, At the point
whore the veilsd folds Of the duF8 mater
,uuias 10 common oonhuenti which 10
called the torcular or compress OF Herophllus,
from the name of the anatomst who hrst de-
scrlbed It, These conjectural explanations
have been handed down 10 us; and lt is only
of late years that experiment has succeeoed
In proving their falsity. In fact, 1t has been
shown by direct experiment that, during
sleep. the brain, instead Of being congested,
Ia OH the contrary pale and bloQdleasi while
In state of wakefulness the circulation, De,
coming more active, proVokes dow OF blood
proeortioned to the intensity Of cerebral &C.
tivlty, In this respect natural sleep and tne
ape ,tnelic sleep OF chOroform are alike; In
both cases the brain, sunk Into rest or mac
tiylty, presents the Bame paleness and rela-
live bloodlessnesS,
The experiment Is made In this manner:
part of the bopy covering OF an animars skull
is carefully removed, and the brain laid bare
80 as 10 study the circulation at the surface OF
this organ. Then ohlorof9rm is anmlnlsteiea @
stage of the action of the chloroform, the
brain la observed to grow oongested and TO
Ian over at the edges; but as acon as the stage
of anestbelio sleep ls reached, the substance OF
the brain sinks In and grows paler, presenting
a languid movement Of capillary circuation,
which lasts as long as the slate OF sleep or
cerebral rest continues. For the study OF tne
brain In natural sleep circular trepnn Is
made on a dogs head, and the piece OF bone
removed is replaced by watch-glass carefully
adjusted to the exact opening, 80 as to pre-
vent the Irritating action OF The air. The anil
mails subjected to the operation survive 1t;
and observations on their brain through this
sort of window, while awake and when
asleep, prove that when the dog ia asleep
affluX OF blood ia regularly noticed on his
awakening, when the functions Of The brain
resume their activity. Facts analogous to
those observed In animals have heen studied
directly In the human brain. Upon a person
Injured by frIghtful railroad accident the
effect OF considerable Lisa OF brain substance
was examined, The brain was visible over
surface OF three BY elk lnches. The patient
suffered frequent and severe attacks of cpl.
lepsy and coma, during which the brain lnVa-
rlabiy expanded. Sleep succeeded these at
tacks, and the cerebral hernia gradually sub.
sided. When the patient awoke, the brain
again projected aud rose 10 the level OF the
surface OF the external bony table. In the
case of another person injured In consequence
of q fracture of the skull, the cerebral clrcula-
tIon was studied during the administration of
anestbetics. With the frat inhala,ions the
surface of the brain became branchy and
filled with blood; the flow of blood aud throb-
the brain 4 a4a and s%bsSsa nsG at the
crees below the opening, while at the same
time J growing relatively pale and bloodless.
Briefly then the brain is governed by the
ali ihe ORGANS. By virtue of this law, when
the organs are at rest and their action sus-
and it Increases on the contrary, as soon as
activity is resumed The brain repeat, Is no
execution to this general law, az had been
SUPPOSED, for il Is now demonstrated that the
state Of sleep coincides not with congestion,
brain .1CIaude Bernard, in Popular Science
MOnthlu for November,