American union. [volume] (Morgantown, Va. [W. Va.]) 1855-1859, 1856-03-29

1here are two hun red and eighty
bones in the human body, exclusive OF
the teeth. These bones are composed
OF animal aud earthly materials, the for.
mer pireponde' ating in youth aud the
,atter In old age, rendering the bone
brittle. The most important Of the
bones IL the spine, which is composed
OF twenty-four small bones called the
vertebre, one on the top of the other
curiously hooked together, and fastened
by elastic !igaments, forming pillar. so
TO speak by which the human frame is
supported.
There are two sets Of muscles, one to
draw the bone one way, and the other
to draw it back again. We cannot bet
ter describe the muscles than by compa-
ring them to fine elastic threads, bound
up IN their cases Of skin. Many mus.
cles terminate in tendons, which arc
stout cords. such as may be seen traver-
sing the hack of the hand. just within
the skin; and which can BIO observed to
move when the hand is open or shut
Every motion we make even the invol.
uniary one OF the breathing, is perform.
ed through the agency of The muscles.
In adults there are about fifteen quarts
OF blood, each quart weighing about two
pounds. This blood is of Two kinds
The arterial and venous. The frs, is
the pure blood as it leaves the heart TO
nourish the frame, and is of bright
vermillion color. The last is the blood
as 1t returns TO the heart, loaded with
the impurities of the body TO be there
rehned, and is of purple hue. Every
pulsation Of the heart sends out about
two ounces of arteiial blood, and as
there are from seventy TO eighty beats
in the minute, a hogshead of blood pas.
ses through the heart every hour. In 70.
yers the motion is accelerated; the waste
goes on faster than it can be recupera-
ted; and consequently death ensues if
the fever is not checked.
The stomach is boiler, if we NAV
| use such an expression, which drives
the human engine. Two sets of mus
clos crossing each other traversely, turn
the food over and over, churning it up
in the gastric uice till it has been re-.
duced to tho consistency of thin paste.
This process requires from two to four
hours. Emerging from tho stomach,
the food enters the small intestine, where
it is mixed with bile and pancetric Juice
and conN into cnyle. These small
iniesiines are twentyfour feet long,
closely packed Of course, and surround.
ed through tho whole length with small
tubes which acts like suckers, and draw.
ing OFT the chyle, empty it into large
tube, named tho ihoracic duct, which
run up the back, and discharges its con.
tents into the jugular vain. whence it
passes into the heart, to assist in forming
arterial blood. o
The lungs are two bags connected
with The open air by the windpipe,
which branches into innum cradle small
tubes all over the inside of the lungs,
each tube terminating in a minute air
cell. The other surface ofthese air. cells
are full OF capilarics or infinitely small
veins, membrane only dividing the air
ftom the blood. The impure portion of
veinous blood is carbonic acid, which
having stronger affinity for air Than
Tor blood, passes through this hin mem
! orane IN gaseous state, combines with
tho air in.the air.celi, and is expelled
| with the next respiration. Meantime
The oxygen Of the air unites with the
blood and becomes purified, then pas
sing into the heart, being mixed with
| chyle, it is forced through the BODY as
l'fe-giving and artcrial blood.