Julie Ann Hensley, age 15, of Champaign, Ill., for her question:
HOW IS CHARCOAL MADE?
Charcoal is a spongy, black substance that is almost pure carbon. It is the product that is left when animal or vegetable material is partially burned. It can be made from wood or animal bones by heating or burning them in such a way that allows the water and gases to be driven off, leaving the solid material behind as charcoal.
There are two different ways in which charcoal can be made from wood.
The first method calls for the covering of a pile of wood with dirt. A firs is built at the bottom of the pile and the wood is allowed to burn slowly, or char. This method has been used for hundreds of years in northern Europe. it is wasteful because it doesn't provide a use for the escaping gas.
The second method puts piles of wood into iron buggies that are then pushed by a locomotive into ovens called retorts. A hot fire is partially smothered by closing the draft. The wood slowly turns to charcoal and the escaping gases are collected in another chamber. Valuable substances are condensed from the gases, including wood alcohol, acetic acid and acetone.
Charcoal is a great fuss for backyard barbecue pits. It gives a nice, hot fire that doesn't have a lot of smoke or high flames. It is ideal for cooking hamburgers, hot dogs, chicken or fish. Charcoal adds a good taste.
Charcoal's first important use came when it was called on to smelt iron ore. Coke has since been substituted for charcoal in the iron industry, but there are still many other uses for the material.
In 1812 charcoal was first used to clarify the syrup products of sugar refining, and it is still used for this purpose.
Wood charcoal was once used in making gunpowder, and it is still used in the manufacture of blasting powders.
Since charcoal is a poor conductor of heat, is is used as an insulator.
Charcoal also is used to make some medicines, water filters, pencils, toothpastes and polishes.
Sticks of fine grained charcoal, most of the time made from willow wood, are used by many artists for drawing and sketching.
During World War I, nn important nee for wood charcoal was discovered. Scientists found that if charcoal was subjected to intense heat, its power of absorbing gases was increased greatly. After the charcoal was treated in this way, it was used in gas masks.
Charcoal used in the best gas masks is made from coconut shells.
Charcoal made by heating bones in a retort and allowing the gases to escape is called bona black. This material 1s very useful as a filtering agent because it absorbs impurities, coloring material sad bad odors.
Lampblack and ivory black era used in printing inks and as a pigment in oil paints. Lampblack is soot taken groin burning resins, turpentine, tar, oil or fats. Ivory black is wads from burning waste chips of ivory.