Chapter VIII 
THE MICROBES’ GREATEST SERVICE 
TO MANKIND 
TT 7E so often think of microbes as the cause 
▼ V of all kinds of dread diseases, that we 
almost forget their useful services to mankind. 
Besides the work that they do in fermentation, 
helping us to make butter, cheese, vinegar, 
bread, and other things, there is another job 
they do that is the greatest of all. This is the 
decay and destruction of dead animal and plant 
bodies. 
Here, microbes, while satisfying their own 
need for food, are playing a necessary and im¬ 
portant part in the world’s work. Plants and 
animals use as their food, lifeless material taken 
from the air, from the soil, and from living 
things, and transform it into the substance of 
their bodies. When they die, all this material 
in 
What is the 
greatest wor\ 
of microbes? 
