The independent. (Harrisonburg, La.) 1853-18??, 1858-08-18
Wonders of The Human System.

! diey dppiauus inc CoNtTlNaICe Uy WHICH
everything we eat and drink is made to glide
on its road to the gullett, over the entrance
OF the windpipe without failing into it. a
little movable lid, the epiglottis, which is
lifted up when We breathe, is pressed down
upon the chink of the air passage by the
weight of the food and the action of the
muscles in swallowing it. Neither solids nor
liquids, in short, can pass without shut,iue
down the trap-door as they proceed. But
this is only part OF the safeguard. The slit
at the top ofthe windpipe, which never closes
entirely when we breathe, is endowed with
an acute sensi5!ity to the slightest particle
Of matter. The least thing which touches
fthe margin ofthe aperture causes its sides to
to come firmly together, and the intrudng
body is stopped at the inlet. 1t is stopped,
but unless removed, must drop at the next
inspiration into the lungs. TO effect its ex-
pulsion. the sensibility Of the rim at the top
of tho windpipe actually puts into vehement
action whole class Of muscles placed lower
than its bottom. and which, COMPRISING the
chest over which they are distributed, drive
out the air with force that sweeps the often
ding substance before it.
The conTulsivo coughing which arises
when we are choked. is The energetic effort
Of nature for our relief when anything chan
ccs to have evaded the protecting epiglottis.
Yet this property, to which We are cons antly
owing our lives, is confined to a single spot
in the throat. 1t does not, as Sir Charles
Bell aa:rns, belong to the rest of the wind
;pipe, but is limited to the osifce, where alone
it is needed, Admirable, too, it is to observe
that, while thus sensitive to the most insignif-
cant atom, it bears, without resentment the
atmospheric currents which are constantly
passing to and fro over its irritable lips. at
rejects" says Paley, 'the touch of crumb
of bread, or drop Of water, with spasm
that convulses the whole frame; and yet, left
TO itself and its proper office, the intesmission
Of air alone, nothing can be so quiet. It does
not even make itself felt; man does not
know that he has trachea." This capacity
of perceiving with such acuteness, this i'm.
patience of oaense, yet perfect rest and ease
when let alone. are properties, one would
have thought, not likely to reside in the same
subject. 1t is to the junction, however, of
these almost inconsistent qualities in this,
as well as in some other delicate parts of the
body, that we owe our safety and our COM
fort-our safety to their sensibility, our com
fort to their repose.
7 Another of tho examples adduced by Bell
is that of the heart. The famous Dr. Hsryey
examined, at the request of Charles l., a
nobleman Of the Montgomery family, wLo,
in consequence of an abscess, had fstulous
opening into the chest, through which the
heart could be seen and handled. The great
physioloSist was astonished to find it insen-
sible. 81 then brought him, he says, "to the
king, that he might behold and touch so
extraordinary a thing, that he might perceive,
as did, that unless when we touched the
outer skin, or when he saw our fingers in the
cavity, this young nobleman knew not that
We touched the heart. Yet it is to the heart
that we refer our joys, our sorrows, and our
affections; we speak of a good-hearted and a
bad hearted, a true-hearted and heart!ess
man. Shielded from physical violence by an
outwork of bones, it is not Invested with
sensations which could have attributed moth
ing to its preseIN alton, but, while it can be
grasped with the fingers, and give no intima
ton of the fact to its posses:or, it unmistaka-
bly, responds to the varied questions of the
mind, and, by the general consent of man
kind, is pronounced the seat of our pleasures,
griefs, sympathies, hatreds, and love. Per-
sons have frequently dropped down dead
from the vehemence with which it contracts
or expands upon the sudden announcement
of good or bad news-its muscular walls
being strained too far in the upward or
downward direction to enable them to return
land one of the purposes which this
property of the heart is probably designed to
subserve is, to put check upon the passions
through the alarming physical sensation they
1excite.
The brain, again, is enclosed in bony
lease. All our bodily sensations are depend
ant upon the nerves, Int even the nerves DO
not give rise to feeling unless they are in
connexion with the brain. The nervous
chord which, in familiar language, is called
the spinal marrow, is the channel by which
this communication is kept up in the major
part of them: and when section Of what
may be termed the main trunk for the con-
veyance of our sensations is diseased, and
by the breach in its continuity, the nerves
below the dlsordered part can no longer send
their accustomed intelligence to the brain,
the portion Of the body which thus becomes
insoate NAV be burned or hacked, and no
more pain will result than if it belonged to
dead carcass instead of to living man.
The brain. therefore, in subordination to The
mind, is the physical center OF all sensation.
Yet, strange to say, it is itself insensiole to
the wounds which are torture to the skin,
and which wounds the brain alone enables
Us to feel. ut is as insensible," says Sir
Charles Bell, "as the leather Of our shoe, and
piece may be cut off without interrupting
the patient in the sentence that he is uttering
Because the bone which enveIops it is its