The three most unusual substances in the world.

For our purposes, unusual substances are those that have a large number of remarkable properties - so while diamond is by far the hardest substance that we know of, and an excellent conductor of heat, it doesn't qualify for the top 3 (IMHO - in my humble opinion). These three substances are so unusual that they clearly must have been created with these specific purposes in mind, yet it defies the imagination to believe that any scientist could have invented substances so complex and plentiful with all of these properties and uses. It turns out that all three of these substances have had an immeasurable impact on our history. (We will avoid fruitless argument by refusing to define 'substance'.)

WOOD - the third most remarkable substance.

Wood is truly remarkable for a number of reasons. It has contributed to our survival and the development of civilization. First of all, it is the only material available in great abundance that floats on water (aside from ice). Without observing logs floating in water, people would have taken a lot longer time to come up with the idea of ships and boats. Imagine if the only buoyant object you had was a gourd. How long would it have taken until someone tried to make a scaled up gourd that someone could sit in? Imagine the first few gourd boats capsizing and their owners drowning -- quite discouraging. Would Britannia ever have ruled the waves? Without boats, the exploration and colonization of the continents and islands of the world would have been seriously hampered. Even today, maritime commerce plays a very important role in the world economy - even though our ships are no longer made of wood.

Wood is also easy to carve and work with. Its natural grain and flowing patterns allow the combination of beauty and utility in tables, bowls, shelves. Its colours cover a wide range: red, green, yellow, brown, black, and nearly pure white. Some wood is aromatic.

The mechanical properties of wood make it an important building material around the world. In Canada one of the benefits of using wood over stone is that it has better thermal insulation properties. It is fairly tough and resilient and not brittle, and grows in convenient pole like shapes -- great for making telephone poles! You can make almost anything out of wood from pianos to pencils. The tall white pine trees of Maine used to be used masts for clippers. Most early airplanes had a wooden propellers. Most furniture is still based on wood. I believe that all railway ties are still made of wood (although many telephone poles are now being replaced with other materials).

Wood makes an excellent fuel. Throughout history it has been used for heating, cooking and light. Even today, many houses are heated with woodstoves. The production of charcoal from wood enables the smelting and refining of copper and iron ore and was a vital part of our technological development. Interestingly enough, fossil fuel also comes from wood and other parts of plants. Truly indispensable!

Paper also comes from wood. Imagine feeding pig skin or papyrus reeds into your laser printer! We use it for all sorts of writing; everything from cardboard boxes, to post-it notes, to income tax forms. (Note that some good quality paper is made from rags.)

Other important products from trees, besides wood are: oxygen, cork and cinnamon from bark, fruit, nuts, and some medicines. Rubber from the unusual South American rubber tree played a vital role in industry in the late 1800s. British spies smuggled precious rubber tree seeds to Malaya to break the deadly Portugese monopoly. In World War II, Japan controlled all the Asian rubber plantations, except for Ceylon. The United States launched a major scientific program to find a way of producing rubber synthetically to manufacture tires for planes, jeeps, etc. (Other military uses for wood have been archery, spears, palisades, battering rams and catapults.)

Trees provide an important habitat for birds and small animals. Their roots and leaves (together with smaller plants) control runoff and soil erosion.

Wood is remarkable in that it grows by itself, automatically replenishing our supplies. Unfortunately, human greed is destroying vast tracts of forest with no thought to the future. Mahogany forests have been cut down to make moulding for pouring cement. The wood is used once and then discarded. Because of the great demand for it, as old growth forests are chopped down, they are often replaced with imported faster growing species like spruce, or cash crops (like oil palms in Borneo). Slash and burn agriculture has destroyed much of the Amazon. Indonesia has a nasty habit of setting huge jungles on fire to clear the land for more lucrative purposes.

It is impossible for me to imagine the earth without wood. Canada in particular has been blessed with an abundant supply of this material. What a remarkable material!

Finally, the most famous and influential man who ever lived was a carpenter and died on a tree.