The study of bacteria is called bacteriology. It is one of the more modern sciences.
Bacteria were first seen through a microscope nearly 300 years ago, but no one knew they were important until 200 years later. Then scientists began to find out how much these tiny plants help and harm us. After that the science of bacteriology grew fast. From the first most bacteriologists have been chiefly interested in the bacteria that cause disease.
In the beginning scientists had trouble raising only the kinds of bacteria they were interested in studying. Other kinds grew right along with the wanted kinds. It was hard to shut out these unwanted bacteria. But finally scientists learned how, and now they raise just the kinds they wish to study.
