Toni Washuta, age 10, of Tucson, Ariz., for her question:

WHAT IS THE GERM THEORY?

Not too long ago people didn't know what caused disease and sickness. Some thought they were caused by the gods as a punishment. Some thought the cause was demons, or bad air, or bad blood.

In 1676 Antony Van Leeuwenhoek invented the microscope which made it possible to see germs. Then in 1825 Agostino Bassi discovered that bacteria caused disease and 35 years later Louis Pasteur discovered a cure for the disease by killing the bacteria.

Pasteur started the    germ theory that is known today. Robert Koch, in 1876, proved that bacteria caused anthrax in cattle and four years later Joseph Lister discovered that killing the bacteria in a surgical wound stopped the infection that frequently occurred after surgery.

The germ theory says that disease is caused by living germs which enter the body. These germs can sometimes be spread by contact with an infected person. Germs are bacteria, fungi, viruses or one celled animals which cause disease.

Lister learned that microbes in fresh, pure air do no harm to a wound but there was~trouble when they were carried to the wound by hands, clothing, bandages or instruments.

From this came the foundation for what is called the "Aseptic treatment." Antiseptics or microbe destroying substances are not put right on the wound. They are sometimes used on dressings and are used to sterilize, or kill, the germs, on bandages, instruments and anything else that may touch the wound.

Medicine today is continuing its fight against germs. A great deal is still to be learned about the application of the germ theory, and it is for this reason that we can be glad that research continues forward in hospitals and medical labs all around the world.