200.WHAT IS LEPROSY?
Since ancient times, the disease we call leprosy has terrorized man. Aside from what it did to a person’s body, a person with leprosy was forced to live away from other people. No one wanted to come near him or have him around; a leper had to spend the rest of his life alone.
Today we know much more about leprosy and treat this disease differently. Leprosy is an infectious or contagious disease which affects the skin or the nerves, or both. The bacteria that cause the infection were discovered by a Norwegian named Hansen, so leprosy is also known as Hansen’s Disease.
199.WHAT IS INSTINCT?
Most of us think that every action we take is voluntary — that we sit down and stand up because we want to, or shake hands because we want to, and so on.
But the actions of people and all living things are really not so easily explained. For example, as you ride a bicycle, you may make dozens of motions without even thinking about them as you do them. These actions are the result of learning and experience.
198.WHAT IS CALCIUM?
The average body of a human being contains about three pounds of calcium. Most of this is found in the bones. Calcium is an essential part of the structure of the bone.
We might, in fact, compare the structure of a bone to reinforced concrete. The bone has certain fibers called collagen fibers which are like the flexible iron wires often embedded in concrete. Calcium forms the bed in which these bone fibers are fixed.
