Year: 1860




There are about two hundred bones in
the human body, exclusive of the teeth.
These bones are composed Of animal and
earthly materials, the former predomina-
ting in youth and the latter in old age,
rendering the bones brittle. The most
important of the bones is the spine which
Is composed Of twenty-four small bones,
called the vertebre, one on the top Of
the other, ouriously hooked together and
fastened by elastic ligaments, forming
pillar by which the human body is sup
ported.


The bones are moved by the muscles,
of which there are more than 500. The
red meat or 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 to draw them
back again. We cannot better describe
the muscles than comparing them to fine
elastic thread bound up in their cases of
skin. Many muscles terminate in ten
dons, which are stout cords, such as may
be seen traversing the back of the hand,
just without the skin, and which can be
observed to move when the and is open
or shut. Every motion we make, even
the involuntary one of breathing, is per-
formed 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 noursh the frame,
and is of bright vermillion color
The last is of the blood as it runs to the
heart loaded with the impurities of the
body, to be there refined, and is of a pur-
pie hue. Every pulsation of the heart
sends out two ounces Of arteral blood
and there are from 10 to 80 beats in min
ute, hogshead of blood passes through
the heart every hour. In fevers the pull
sations are accelerated and consequently
death ensues if the fever is not checked.


The stomach is boiler, it 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 till it
has been reduced to the consistency of
thin paste. This process requires from
two 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 chylc. These small
intestines are twenty -four feet long, closely
packed of course, and surrounded through
their whole length with small tubes which
are like sockets, and drawing off the
chyle, which runs up the back and dis
charges 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 windpipe, which
branches into innumerable small tubes,
all over the inside Of the lungs, each
terminating in minute air cell. The
outer surface of these air cells is full of
small capillaries, infinitely small veins,
thin membrane only dividing the air FROM
the blood.


The impure portion of venous blood is
carbonic acid, which, having stronger
affinity for air than for blood, passes
this membrane to gaseous state,
combines with the air in the air cells, and
is expelled with the next respiration
Meanwhile the oxygen of the air unites
with the blood, and becomes purified;
then passing into the heart, being mixed
with chyle, it is forced through the body
as liie-giving and arterial blood


The skin serves an important purpose
in carrying off impurities of the system.
1t is traversed with capillaries of the body.
1t is also perforated with the countless
perspiration tubes, the united length of
which amounts to twcnty.eight miles,
and which drains away from three to
four pounds of waste matter every twenty
four hours or fve-eights Of all the body
discharges.


The nerves are another curious feature
Of the animal economy. These are, how
ever, but little understood. They act as
feelers to tell the wants of the body, and
also as conductors to will the muscles to
act. They branch out from the brain
and spine over the whole frame in infni-
tely fine fibrcs, like branches or twigs to
trees.