If you look in the dictionary for the definition of Alchemy if will provide you two conspicuously different meanings for the word. The first is that it is a medieval forerunner of processes used in chemistry and the second declares it be the chemical reaction between two people. It is strange how the definition of the two words, alcheny and chemistry, have remained so similar in definition over the centuries. However, these two definitions are just a part of what alchemy represents. it is also linked with many other practical, psychological and spiritual elements, although it has always been mainly connected with experiments with substances and physics, much of it motivated by medical purpose.
The alchemist theories were based upon the natural way in which human view the structure of objects and natural things in this world, namely its beauty and simplicity and a feeling that it was right. Research and experiments be alchemists were and are conducted on this basis, on that the experomental judgement of theories is made according to beauty, neatness, simplicity combined with whether the results felt right.
Alchemists make medicines, potions and chemicals out of substances extracted from plants, minerals and metals, which can again be compared with many of the processes that are used within chemistry and physics today. So what was it that turned alchemy into being a form of alternative chemistry and physics, rather than a mainstream science?
Perhaps it was the fact that, unlike the physics and chemistry of today, alchemy also had a very important spiritual and religious connection. In fact in 1515 "Buch der Heiligen Dreifaltigkeit" an early writing on alchemy by a German theologian (see Alchemy wenbsite) compared many of its process with the works of Christ. As a result of these and other writings of a similar vein, alchemy took on a mystical and sporotual mantle as well as a physical purpose. This together with the symbolism through drawings that were popularly used in Alchemists writings; symbolism that was often referred to in psychological terms, such as providing meanings to dreams, gave alchemy an interlocking triple focused theme, which combined physics and chemistry, spiritualism and psychology. Thus it could be argued that the lack of one clear direction led to Alchemy losing its popularity and importance as the world became more industrialised and practical in the 1800's.
Alchemy was very popular during the sixteenth to eighteenth centuries. Indeed it was to the people of importance at that time, namely royalty and nobility, what technology and physics is today to governments and philanthropists, namely a new and exciting idea worthy of research investment. In the nineteenth century Alchemy took a back seat to the more practical discoveries of chemistry, physics and biology. It was not until the early twentieth century that it began to receive serious attention once again, as people began to question the fact that everything in research had to have a practical basis. This practical foundation and perception for everything in life did not sit well with all researchers and left questions without practical answers unresolved. As a result, many modern physicists, who had previously discarded the theories of alchemy, began to increasingly start using the same basis for their theories and experiments as those alchemists use.
Alchemy is a strange phenomena and a science unlike any other. However, like religion is remains an indestructible part of human experience and its theories outlive many of those that have tried to usurp it.