Loudon free press. (Loudon, Tenn.) 1852-1855, 1853-12-09
From the Scientific American


nervous system.
The nervous systems is divided into the ccre.
bral} spinal, and ganglionic. Through the &c.
rebral we are brought in connection with the
external world. We perceive through it, and
through it we recognize sensations of pleasure
or pain The spinal system pfesides over all
our ingestions and elections; guards all the ave-
nues that connect the internal organs with the
external world; governs the spincters; retains
what we have within; and prevents the introduc
ton from without of what would prove noxious
if admitted. The ganglionic system relates to
all the operations of assimilation; manages
the secretions; presideS over the growth of the
body; and when deranged, is the immedate
cause of maraSmus.
The action of the nervous power upon the
muscles is threefold: direct, reflex, and retro
grade. Of the direct action, it is general law,
which is centuries old in the book, yet, while,
it was supposed to be the only action of which
the nervous system was susceptible, never was
applied to physoogy,-that it is always down
ward, e., from the center to the exremty;
from the point where the action commences
along the course of the nerve till it is too small
further to be traced. The doctrine of the re-
hex actions is DR.. Halls own. He was study
ing the phenomena that transpire within the
lungs of the frog, when he noticed thata slpht
irritation of the toe of the animal created a
spasm of the extremity. He fell to wondering
what was the cause Of the spasm. He had en-
cited nervous action, but he had not touched the
brain. He had stimulated the excitability of
the muscles of the part, doubtless through the
spinal system, since all motion is communica.
ted to the muscles through the medium of that
system, yet he had not reached the medulla
oblongata. The jerking of the frogs foot was
to him like the apple falling to Newton. He
suspected, and subsequent experiments confirm
his suspicious into convi c:ions, that in touching
the skin he had touched the extremities of
nerves, whose office it was to carry back to the
ccnterS, messages Of communication with the
external world This point established, the
circle was completed, and the threefold nevous
action--direct, reflex, and retrograde. easily
demonstrated. In illustration of these princi-
plies, DIR. Hall performed some experiments.
He divided the spinal marrow of the frog
By this operation all sensibities was removed.
He laid it upon its back; there it would Law till
it was dead, unless something should irritate
the skin, and through the reflex action spoken
of cause the muscular contractions
The freq was then pinched, but did not respond
by spasm. This state of shock, said the Doc
tor, is temporary. 1t passes rapidly away
And in moment after, pressing on the skin of
the toe, the whole body was convulSed. -
Here was an Illustration of DR.. Halls new law,
of an ascending movement from the skin to the
center, yet not acting through the brain, but
reflected from the spinal center.
Next he took off the skin of one foot. No
irritation ofthe denuded flesh caused any excita-
bility of the muscles Next he grasped the
spinal nerve in his forceps, and both legs were
violently convulSed. Then he severed the um-
bar nerve of the extremity that was not denu-
ded; the part Supplied by that nerve was convul-
sed. Now, no irritation of the skin produced
any spasmodc action, for, though the cutane-
Gus nerves carry the impression to the center,
there was left no medium for their direct action
to reach the muscles.
The learned lecturer then deduced some very
important practical lessons from these expert
megs PARA ySIs eHgsed 81 shock is ge8s.
sis passes away while be does not know it, but
from diSuse of the paralyzed part, the inaction
in it may remain. The determined will of the
enlightened physician works almost miracles in
such case and the bystander may add the
case, cured by moral means, to the last, where
in the imagination is said greatly to aid the
cure. PARALYSIS, in which there is no spasmod-
in action is very generally of cerebral origin
where there is spasmcdic action, the spinal col
nn,n is also affected. The practical physician
will see how his treatment should vary with
these varying and seats of the disease.
The lecturer dropped small Quantity of the
solution of strychmine upon another frog, and,
whereas he had before been dull and half asleep,
as in is his custom in winterish weather, he
suddenly exhibited great deal of life and en-
cry. SooRShis muscular activity took The
form of hydrophobia. When let alone, he9ay
still and motionless. Touching him ever $50
gently on the back produced a spasm. These
spasms being frequently provoked, he stretched
himself out, and, to all appearances, died
Rubbing him would secure aslight spasm, but
each returning one grew fainter, till the mus.
cles ceased to respond to the irritations of the
skin. Dead as he seems, remove him TO a cool
place, and in the morning he will be well and
strong and ready to be useful as the subject
! of another experiment. Just so it is with pa
tents suffering under hydrophobia. We must
place them in quiet, cool and comfortable quar-
tiers. and for their lives sakes, letthem alone
| Handling them hurrieS back the spaSm, and
each new spasm hurres the life out them. lily
dorphobia kills in three ways: First, by laryn
qisn,us; second, by repeated excitation causing
repeated shocks: and third, by the effect. of the
poison upon some internal organ. Tracheoto
my is the remedy for laryngisinus. Perform it
and death from that cause IS impossible The
second cause is removed, if at all, by perfect
Quiet and the avoidance of every possible thing
that can annoy the patient. The third, when
the disease reaches that stage, is probably be
yond the cure of man.