St. Mary's beacon. [volume] (Leonard Town, Md.) 1845-1863, 1858-10-28
Facts about the Body.

There are about 200 bones in the human
body, exclusive Of the teeth. These bones are
composed Of animal and earthly materials, the
former predominating in youth, ard the latter
i'm old age. rendering the bones brittle. The
most important of these bones is the spine,
which is composed OF "a small bones, called
the vertebra, one top of the other. curiously
hooked together, and fastened by elastic liga-
merts, forming pillar, by which the human
frame is supported.
The bones are moved by the muscles, of
which there are more than 5OO The red meat
If heef, the being excluded is the muscular IA
brio of the OK. There are two sets of muscles,
one to draw the bone one way, and another
to draw it back again. We cannot better
describe the muscles than by comparing them
to rine elastic threads. bound up in their cases
Of skin Many muscles terminate in tcnduns.
which are stout cords, such as may be seen
traversing the back of the hand, just within
the skin. and which can be observed to move
when the hand is opened or shut. Every mo-
tioE we make, even the involuntary one of
breathing, is performed through the agency of
muscles.
In adults there are about fifteen quarts of
blood, each weighing about two pounds This
blood is of two kinds, the arteriai ana vencus.
! The first is the pure blood, as it leaves the
heart tn nOurish the frame, and is Of a bright
vermilGon culor. The last is the blood as il
runs to the heart, lna,led with the impurities
Of the body, to be there refined, and is Of a
purple hue. Every pulsation of the heart
sends out two ounces of arterial blood; and, as
there are from 20 to 80 beats in a minute. a
hogshead OF blood passes through the heart
every hour. In fevers the pulsations are ac-
CELEBRATED, consequently death ensucs if the
fever Is not checked
The stomach Is the boiler, If we may use
such figure, which drives the human engine.
Two sets Of muscles, crossing each other. turn
the food over and over, churning it up in the
gastric juice, tell it has been reduced to the
consistency Uf thin paste. This process re-
quires from two to four hours.
Emerging from the stomach the food enters
the small intestines, where it is mixed into bile
and the pancreatic juice, and converted into
chylc. Thee small intestines are p feet long.
closely packed of course, and surrounded
through their whole length with small tube.
which are like sockets, and drawing of the
chyle, empty into a large tube named the
thmscic duct, which runs up the back and
discharges the contents into the jngular vein
whence it passes in the heart to assist in form
ing the artcrial blood.
lie lungs are two bags, connected with the
open air by the wihdpipe, which branches into
innumcrable small tubes, all over the inside
Of the lungs, each terminating in a minute air
cell. The outer surface Of these air cells in
full Of capilaries, infinitely small veins. thin
membrane only dividing the air from the blood.
The impure portion Of venous blood is car
bonic acid, which, having a stronger affinity
for air than fur blood, passes through this
membrancc to gaseous state combines with
the air in the air cells, and is expelled with the
next expirati n. Meantime the oxygen of the
air uniteS with the bloOd and becomes purified,
then passing into the heart, being mixed with
chy'e, it is forced through the body as life
giving and arterial bloo,l.
The skin serves an important purpose in
carving of impurities Of the system. It is
traversed with capillaFies which contain more
blood, in the aggregate, than all the other ca
pllilaries OF the body. It is also perforated
with countless perspiration tubes, the united
length Of which amounts 90 % miles. and
which drain away frum three 10 four pounds Of
waste matter every % hours, or fve-eighths
of all the body discharges.
The nerves are another curious feature of
the animal ecOnomy. They are however, hsas
littse understood. They act as feelers to tell
the wants Of the body, and also as conductors to
VIII the muscles to act. They branch cut
from the brain and spine over the whols frame
IN infinitely fine fihres ike branches or twigs
10 trees,
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