The Messenger. [volume] (Georgetown, Del.) 1858-18??, 1860-02-16
4 SIX BY gH
FACTS ABOUT THE BODY.

There are about two hundred
bones in the human body, exclusiv,
Of the teeth. These bones are com
posed of animal and earthly mater
ials, the former predominating il
youth and the latter in old age. rem
derng the bones brittle. The mos
important of these bones is the spine
which is composed of twenty-four
small bones, called the vertebrae, on,
on top Of the other, curiously hooked
together and fastened by elastic
ligaments, forming a pillar by which
the human body is supported.
The bones are moved by the mus
cles, of which there are more than
five hundred. The red meat OF
beef, the fat being excluded, is the
muscular fabric of the OK. There
are two sets of muscles, one to draw
the bones one way, and another tC
draw them back again. We cannot
better describe the muscles thar
comparing them to fine elastic
thread bound up in their cases Of
skin. Many muscles terminate in
tendons, which are stout cords, such
as may be seen traversing the back
of the had, just within the skin, and
which can be observed to move when
the hand is opened or shut. Every
motion we make, even the involun-
tary one Of breathing, is performed
through the agency Of muscles.
In adults there are fifteen quarts
of blood, each weighing about two
pounds, This blood is of two kinds,
arterial and venous. The first is
the pure blood, as it leaves the heart
to nourish the frame, and is of a
bright vermillion color. The last is
the blood as it flows into the heart
loaded 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
70 to 80 beats in a minute, a hogs
head of blood passes through the
heart ever hour. In fevers the pul.
sations are accelerated and conse-
quently death ensuss if the fever is
not checked.
The stomach is a 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, ehurning it
up in the gastric juice till it has been
reduced to the consistency of thin
paste. This process requires from
three to four hours.
Emerging from the stomach the
food enters the small intestines,
where it is mixed with the bile and
pancreatic juice, and converted into
chyle. These small intestlnes are
twenty-four feet long, closely packed
of course, and surrounded through
their whole length with small tubes
which are ike sockets, and drawing
off the chyle, empty into a large
tube named the thoraic duct, which
runs up the back and discharges the
contents into the jugular vein,
whence it passes to the heart to as
sist in forming the arterial blood.
The lungs are two bags connected
with the open air by the wind pipe,
which branches into inhumerable
small tubes, all over the inside of
tho lunge, oooh terminating in a mi
mute air cell. The OUTER surface efI
the air cells is full Of small capillar-
les, infinitely small veins, thin
membrane snly dividing the air
from the blood.
The impure portion of venous
blood is carbonic acid, which, having
q stronger affinity for air than for
blood, passes through this mem
brane to a gaseous state, combines
with the air in the air cells, and is
expelled with the next respiration.
Meanwhile the oxygen of the air
mites with the blood, and becomes
purified; then passing into the heart,
being mixed with chyle, it is forced
through the body as life-giving and
lrterial blood.
The skin serves an important pur-
pose in carrying off impurities of the
system. 1t is traversed with capil-
aries of the body. 1t is also perfo-
'ated with countless perspiration
iubcs, the united length of which a.
mounts to twenty-eight miles, and
which drains away from three to
our pounds of waste matter every
,wenty-four hours or fve-eights JfI
Ill the hndv flisrhar0ac