Wednesday, June 30, 2010

Origins of Chemistry

Before considering Chemistry as a science, let us look back in time when it was merely an art or craft. The difference being in science we study "Why does it work?" and in art or craft we study "Does it work".

Six thousand years ago many arts and crafts were established. Earliest metals were Gold, Silver and Copper. People discovered them and started to use them Gold and Silver in royal vessels and ornaments. Whereas copper was used for both ornaments and practical purpose. Bronze was later discovered and was used specifically for weapons of war.

In 1200 B.C. people started producing Iron by heating one of its Ores with charcoal in a furnace. Iron thus produced was not good in quality. But in 1340 A.D. blast furnace came into use, melting the Iron and thus giving a better quality. This Iron then replaced copper for weapons.

In 500-200 B.C Greeks were famous for thinking. It was not futile. They developed Logic, mathematics, curiosity for nature, and gave the concept for Atom. Aristotle said everything is made of small indivisible particles called Atoms. They developed the idea for elements : Earth, fire, air and water.

At the same time Egyptians excelled in handicraft. In working of metals and glass.

Then came Alchemists in the early Christian Era. The primary objective of alchemists was to find a way to convert any metals into Gold. Also called as Transmutation of Metals. They of course failed. Some alchemists later believed that they needed a substance called "Philosopher's Stone". This precious stone would convert anything with mere touch and can even give perpetual youth. That's why it is sometimes called "Elixir of Life". Note: Transmutation is now possible but the methods are much more complex than what Alchemists imagined.

Alchemists also discovered Antimony and Zinc metals. And non-metals Arsenic and Phosphorous. They also improved industries as metallurgy, glass-making and dyeing. They also developed modern processes such as distilling, filtering, and grinding, and the beginnings of modem chemistry laboratory.

18th Century was all about burning things. The burning question was what makes a thing burn? Alchemists were replaced by Physicians, druggists and teachers at this point. A German writer Stahl said that a chemical fluid called Phlogiston existed in things that burn and didn't exist in the one's that don't. Burning causes Phlogiston to escape. But this theory could not explain why when Iron is burnt its ashes weighed more. The idea of Phlogiston died.

Discovery of Chemistry:
In 1774 Joseph Priestly and Englishman discovered Oxygen. It then became possible not only to explain burning but to lay foundations of the chemistry as we have it today.

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