76 
WORLD OF INVISIBLE LIFE 
Where do they 
come from? 
most common place for them to settle. The 
bowels, the skin, the bones, and the joints are 
also frequently attacked. The germs do not 
enter the blood, but they cause growths which 
spread through the tissue of the place affected, 
and cause death if they are not stopped by the 
forces in the body that guard a person’s health. 
A healthy person may get tuberculosis germs 
by breathing air into which they have been 
thrown by the coughing, sneezing, or talking 
of a person having the disease. The danger 
of getting the disease is much greater in rooms, 
offices, or street-cars which are used by people 
suffering from it than it is in the open country 
or even in city streets. It can also be caught 
from a sick person by the use, in eating or 
drinking, of anything used by the sick person 
which has not been properly cleaned, so that 
some of the germs still stick on it. 
But the tuberculosis germ, like the pneu¬ 
monia germ, cannot harm the body unless 
something has happened which has weakened 
its ability to fight the microbe. Probably almost 
