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PHYSIOLOGY AND ANATOMY. 15 
_ and these tubes are as small as a hair. It travels along _ 
through “these tubes in the same manner that the particles of 
oil travel along through the little tubes in the wick of alamp_ 
till they unite in larger tubes. These terminate in glands, 
from which larger tubes or pipes collect and carry the ehyle 
from all parts into one common vessel, called the receptacle 
‘or thoracic duct, which holds about a table-spoonful. From 
_this bag a large pipe proceeds, which runs up the back part 
of the chest and along | till it reaches the neck at the top of é 
the left shoulder. It is now poured into a large vein, called 
the subclavian vein, which carries the chyle, together with 
the old blood coming from the veins situated all over the 
body, to the heart, the great fountain of life. The blood now 
formed runs along, being of a dark color, but. which is not 
yet healthy, and flows to the lungs, Here the air we inhale or 
breathe in changes the dark color of the blood tored, as we see it 
when we prick our finger. Then it flows back to the heart, 
and by a contraction of the heart it is thrown into tubes, 
called arteries, with sufficient force and rapidity to carry it 
to all parts of the body. — 
“The blood contains the élainenté of all those substances 
which compose our body. It is the blood. that: makes our 
- bones, our skin, our-hair, and every limb; and it is the blood 
which makes us grow. So you see if we did not eat we 
‘should not have any blood, and so of course we could not 
- grow. You may think it very strange that the red blood 
flowing like the water in a river, can make something as _ 
hard asa bone or flesh ; but when you cut your finger, or 
break a bone, the reason why, after several days or weeks, it 
- heals or becomes well, is, that the blood, in passing the place — 
cut, leaves a little something there, the next time it leaves 
