59.WHAT IS NICKEL?
Nickel forms many alloys which are used in hundreds of industries in many ways. It is one of the most useful metals known to man. But in early times, when chemists first tried to work with it, it gave them a great deal of trouble. In fact, the word nickel is derived from the German word for “imp!”
Nickel is found in meteorites, and it is sometimes found in the free state in small quantities. But the greatest supply of nickel is obtained from certain ores, especially one called pyrrhotite, which is a mineral containing iron, copper, and nickel. Canada is the greatest of all nickel-producing countries.
58.WHAT IS MARBLE?
Nature is a master baker. Deep inside the earth is her oven, heated thousands of years ago by great rising masses of molten rock. In this oven she baked, and with tremendous pressure turned limestone into hard marble.
In its purest form, marble is white. Different impurities often give it shades of pink, red, yellow, or brown, or form wavy lines or patches in it. Different colored crystals caught in the marble sparkle and flash in the sun’s rays. In some marble the remains of fossils add to its beauty.
57.WHAT IS MAGNESIUM?
Magnesium is one of the most amazing metals known to man. It is so light that it is only two-thirds as heavy as aluminum, and you know from your experience with kitchen utensils how light aluminum is! In fact, magnesium is the lightest metal used in industry.
In addition to its lightness, magnesium has another unusual property. It has a tendency to burn. In the form of dust or fine shavings, it catches fire very easily and burns violently.
