Alchemy combines chemistry, metallurgy, physics, medicine, astrology, semiotics, mysticism and spiritualism in a search for knowledge. It has been practised for at least 2500 years in Mesopotamia, Egypt, Persia, India, Japan and China, Classical Greece and in Europe up to the 19th century.
The most famous goal of Alchemy is the transmutation of common metals into Gold or Silver. Other famous goals include the elixir of life and the universal solvent. The now famous Philosophers Stone was believed to be a substance that was believed to be an essential ingredient of the other three goals. The Philosophers Stone was believed to mystically amplify the user's knowledge of alchemy so much that anything was attainable.
Alchemists enjoyed prestige and support through the centuries, though it was not for their pursuit of those goals, nor the mystic and philosophical speculation that dominates their literature. It was for their contributions to the "chemical" industries and inventions - gunpowder, ore testing and refining, metalworking, production of ink, dyes, paints, cosmetics, leather tanning, ceramics, glass manufacture, preparation of extracts, liquors, and so on
Most alchemical works were written using cryptic alchemical symbols, diagrams, and textual imagery with multiple layers of meanings, allegories, and references to other equally cryptic works; and must be laboriously "decoded" in order to discover their true meaning. It is this level of secrecy that leads to the almost occult status of alchemists.
Isaac Newton's Occult Studies
Isaac Newton (1643 - 1727), the noted British scientist and mathematician, was noted for his interest in Alchemy his writings describe how he sought the discovery of the Philosophers Stone and the Elixir of Life, although there is no evidence to suggest he was successful in either attempt.
Transmutation of one element to another
Most people will tell you that one element cannot be transformed into another element, e.g. lead into gold, is impossible. In 1919, Ernest Rutherford used artificial disintegration to convert nitrogen into oxygen using radioactive material. Surely this indicates that it may be possible to convert other elements?
The history of alchemy has become a vigorous academic field. As the obscure hermetic language of the alchemists is gradually being "deciphered", historians are becoming more aware of the intellectual connections between that discipline and other facets of Western cultural history, such as the sociology and psychology of the intellectual communities, kabbalism, spiritualism, Rosicrucianism, and other mystic movements, cryptography, witchcraft, and the evolution of science and philosophy.