The daily exchange. [volume] (Baltimore, Md.) 1858-1861, 1858-08-06
WONDERS OF THE HUMAN SYSTEM.

Paley applauds the cOntrivance by which every
thing we eat and drink is made to glide on its road
to the gullett, over the entrance of the windppe
without falling into it. A little moveabe lid the
epiglottis, which is lifted up when we breathe, is
pressed down upon the chink of the air passage bv
the weight of the food and the action of the muscles
IN swallowing it, Neither solids nor liquids in
short can pass without shutting down the tran
! door as they proceed. But this is only a part OF
the safeguard. The slit at the top of the windpipe
which never closes entirely when we breathe is en-,
dowed with an acute sensibility to the slightest
! particle of matter
| The least thing which touches the margin of the
aperture causes its sides 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 lup~S. To effect its ex
puson, the sensibiity of the rim at the top of the
wlndepipe actually puts into vehement action a
whole class OF muscles placed lower than its bot
tom, and which, COMPRISING the chest over which
they distributed, drive out the air with force
that sweeps the offending substance before it.
The convulsivG coughing which arises when we
are chOked, is the energetic effort of nature for our
relief, when anything chances to have evaded the
protecting epglottis. Yet this property to which
we are constantly owing lives, is confined to
single spot in the throat 1t does not as Sir Chas
Bell atfirms, belong to the rest of the wndpipe but
Is limited to the orce where alone it needed. Ad-
mirabe too is to observe that while thus sensitive
to the mostinsignicant atom, bears without resent
mentment the atmospheric currents which are con-
stantly passing to and fro its irritable lips. at
ltJcCIs, SAYS dlcy, lOucll OF cfunD O DfeaQ,
or drop of water, with a spasm that convuses the
whole frame; and yet, left to itself and its proper
office, the ntermissOu of air alone, nothing can be
so quiet. 1t does not even make itself felt; man
does not know that he has trachea." This ca
pacity of perceiving with such acuteness, this i'm
patience of offence, yet perfect rest and ease when
let alone, arc 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 owe our safety and our
comtort-our safety to their sensibiity, our COM
fort to their repOse.
Another of the examples adduced by Bell is that
of the heart. The famous DR.. Harvey examined
at the request of Charles l. nobleman of the
Montgomery family, who, in consequence of an alb
scess, had tistulous opening into the chest
through which the heart could be seen and handled.
The great Psychologist astonished to find it in
sensible. ] then brought him, he says, to the
king, that he mi ght behold and touch so extraordi
nary 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, sorrows, and
our affections; we speak of a good hearted and
bad-hearted, true-hearted and heartess man.
Shielded from physical violence by an outwork of
bones, it is not invested with sensations which could
have attributed nothing to its preservation, but,
while it can be grasped with the fingers and give
no ntimaton of the fact to its possessor it unms-
takably responds to the varied questions of the
mind, and, by the general consent of mankind, is
pronounced the seat of our pleasures, grefs SYM
pathies, hatreds, and love- Persons have frequent
ly dropped down dead from the vehemence with
which it contracts or expands upon the sudden
nouncement of good or bad news-its muscular
walls being strained too far in the upward down.
ward direction to enable them to return-and 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 thev excite.
The brain, again, is enclosed in bony case. All
a1ar1ap Ia,,+
but even the nerves do not give rise to feeling
less they are in connection 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 great
trunk Tor the conveyance of sensations Is DIS
eased, and by the breach in its continuity, the
nerves below the disordered part no longer send
their accustomed intelligence to the bran the por
ton of the body which thus becomes isolated may be
burned or hacked, and more pain Will result than
if it belonged to dead carcass instead of living
The bran therefore, in subordnation to the
mind is the physical centre of all sensation. Yet
strange to saw it is itself insensibe to the wounds
which are torture to the skin, and which ,vonnds
the brain alone enables us to feel at is as insen
sibe," says Sir Charles Bell, 'as the leather of
our shoe, ana piece may be cut off without inter
ruptng the patient in the sentence that he is utter
ing. Because the bone which envelopes it is its
protection against injury from without, it has
no perception OF them when directed against its
ownfabrIc, though it is, at the same time, the sole
source OF the pain which these injuries inict upon
the other portion of the system. But the skull Is
no oelence against the effects of ntemperahce OF
Vltlated atmosphere, or too great mental TON. 10
these, consequently the same brain which has been
created 1nsensible to the cut OF knle Is !y awe
and giddiness, headache, and apopiectc oppres-
sl0ns give ample notice to us 10 stop tne evil unless
we are prepared to pay the penalty.-London Quar-