THE LYMPHATICS. 303 
accumulates under the skin, and forms blisters when you get 
badly sun-burned. 
WHAT THE LYMPH DOES. 
Well now, a most marvellous thing occurs within our bodies. 
This lymph which saturates the body like water in a bog, sucks 
from the blood its oxygen and digested nourishment through 
the walls of the blood vessels, and so feeds the cells of our 
bodies. Our bodies are burning all the time. We are con- 
stantly using up the cells of our bodies. They burn away in 
countless millions every instant of time, and are replaced by 
new cells created from the nourishment supplied indirectly by 
the blood, and directly by the lymph. The dead cells, when 
burned up within the body, take the form of carbonic acid. 
This gas is sucked up by the lymph, and through the walls of 
the tiny capillary blood vessels. The latter carry it away in- 
stantly to the larger veins which in turn pour into yet larger 
ones still, until the poison-laden blood reaches the heart. This 
human pump then forces it up into the lungs where it is changed 
by the oxygen gas we inhale. The poisons are thus breathed 
out and escape from the body. 
THe LYMPHATICS. 
Now, you wonder, perchance, how the watery lymph, laden 
with impurities, is drained away. Like a thick network, count- 
less numbers of tiny tubes spread out under the skin, and amongst 
the tissues. These are known as lymphatic vessels, because 
they carry lymph. The blood vessels are unending. They pro- 
ceed from the heart, divide and sub-divide until they form a 
fine network of tiny tubes. These small blood vessels have no 
blind or open endings. When their work is done in supplying 
the lymph with their load of nourishment, and when they have 
sucked up as much poisonous dead matter as they can in the 
form of gas, they begin to run together, forming larger and yet 
larger channels which conduct the blood back to the heart to 
be once again pumped into the lungs. On the contrary, the 
lymphatics have open mouths. The lymph, which saturates 
the tissues, is drained off by these little lymphatic tubes, the 
open mouths of which suck it up and hurry it along into larger 
