Iron

   Iron is a hard, heavy, well known metal. Pure iron is silvery-white in color, but it is seldom seen. Wrought iron is the purest commercial form; yet piano strings, the purest wrought iron in the market, contain three pounds to the thousand of carbon and other elements. When in the presence of a magnet, or when placed with-in a coil through which an electric current is passing, soft iron becomes magnetic. Iron remains unchanged in dry air, but rusts —unites with oxygen—in moist air.
   Iron is the most useful of all metals, and of all metals it is the most widely distributed in nature. It forms a twentieth part of the world's crust. It is essential to life of all sorts. It is found in the green chlorophyll of plants and in the blood of ani¬mals. It occurs in meteorites. The color spectrum shows that iron is present in the Sun. There is an iron mountain near Durango, Mexico. It is a projecting back-bone or dike of solid iron ore,—a huge mass one mile long, a third of a mile wide, and 450 to 650 feet high. Similar hills in Missouri are known as Iron Mountain and Pilot Knob.

Iron meteorite

How does a magnet work?

   If you experiment with a magnet, you will find that it picks up some things but not others. It picks up nails but not gold rings. It picks up needles but not silver spoons. Your magnet is made of a metal called iron, and it will only pick up other things that have a lot of iron in them.
   To see how your magnet works, you have to imagine some things first. Imagine that you could cut it in half. Scientists have done so, and they find that they get two separate magnets. Cut one of the halves in two and you get two more magnets. Now imagine you could go on dividing a piece of your iron magnet until you get the smallest possible bit of the metal. This smallest bit is a molecule. Even this molecule is a magnet, too! Every iron molecule is a tiny magnet. It pulls other iron molecules toward itself.
   If all iron molecules are magnets, then why isn't a nail a magnet? Why can't you pick up a pin with a nail? Scientists think that this is the answer: All the molecules in a nail are mixed up together helter-skelter. Each one pulls on others in a helter-skelter way. But in a magnet the molecules are lined up in an orderly way. They can all make their pull in an orderly way. Their combined pull is so strong that they can draw other separate pieces of iron toward them and pick them up.