Bad odors produced in this way are very harmful and likely to make us sick.

Many people have rotting potatoes and other vegetables in their cellars, and swill barrels, and heaps of refuse in their back yards.

These are all dangerous to health, and often give rise to very serious disease.

We should always remember that bad odors caused by decaying substances are signs of danger to health and life, and that these substances should be removed from us, or we should get away from them, as soon as possible.
~3.

Germs.~--The chief reason why bad odors are dangerous is that they almost always have with them little living things called _germs_.