Richard Claas, age 10 of Watertown
What is wood made of?
Wood is made mostly of air, water and sunshine. This is hard to believe, and we still do not know exactly how the trick is done. The recipe is one of nature's most closely guarded secrets. Yet it goes on every day in every green leaf that grows. Yes, the first part of the recipe for making tough wood begins in tender green leaves. Chlorophyll is the stuff that makes leaves green. It is the magic stuff that uses carbon dioxide gas, water and sunshine to make sugar. Only green chlorophyll knows how to mix and bake these ingredients to make plant sugar, The process is called photosynthesis the sunshine recipe.
Everything in the plant is made from the simple plant sugar of this sunshine recipe, The plant has other tricks for processing it into other substances. Some is changed into starch for storage: Some is made into delicate flower petals and even perfumed oils. Some is turned to fats, proteins rich oils and syrups. And plants convert a good deal of sugar into a durable stuff called cellulose.
This cellulose is used to make the walls for the plant cells, These ee13 walls act to support the plant as your bones act to support your body, For the plant also like your body, is made of countless tiny cells, some of one kind, some of another. The cells that make leaves are more delicate than those that make stems. The cells of the stems are smaller than those of the bark around a tree trunk.
The tree trunk is made of very, very sturdy cells. For it must be strong enough to support the massive limbs and branches. Each year, new cells are added around the outside of the trunk. A larger circle of large cells is made during the lush growing season. A circle of smaller darker cells is added each winter season. This forms the circles of woody rings that tells the age of the tree.
About sixty percent of all this wood is made from cellulose, There is also about twelve percent of unconverted sugar. There are resins and minerals that seeped up with the sap from the ground. There is also about twenty‑eight percent of a stuff called lignin. This acts as a cement to make the sturdy cells of cellulose even more sturdy.
While the tree lives, the sap runs through the outer layers of the wood, The wood inside the trunks and branches no longer works for a living, It is the hard, dry heartwood. Sometimes the heartwood of a trunk is attacked by insects or fungi and rots away, Then we have a dead old hollow tree. So long as there is enough tough wood left to support the tree it makes no difference.
When a log burns, it is the cellulose that seems to disappear; Actually the heat of the fire is breaking up the original sunshine recipe„ The water goes off as invisible vapor. Some of the carbon joins with the oxygen in the air to make invisible carbon dioxide gas, Some drifts off as smoke. The ashes are the resins and cements that need as hotter fire before they can return to invisible gases..