The physical sciences study only the physical reality of existence. Alchemy studies the physical, psychological and esoteric realities of existence.
So instead of Alchemy being dumbed down or primitive chemistry it is a distinct and separate discipline set up to investigate all aspects of creation especially those which the physical sciences dispute and deny the existence of.
More to the point, when a physicist or chemist states that it is impossible to transform an element from the periodic table of elements into to another one, they are completely correct because in terms of physical reality that is impossible. However, in terms of the esoteric reality it is completely possible because the laws of physics are different there.
So when one is examining an Alchemical text such as for example, Nostradamus’s Elixirs, one will see one ounce of mercury listed in one particular recipe. If one uses one ounce of the physical substance of mercury one will kill whoever imbibes that mixture. What he actually means is one ounce of the spiritual (esoteric) substance of mercury which has nothing whatsoever to do with its physical counterpart.
There are a list of some Alchemical terms which may have physical counterparts but which describe esoteric substances or processes and thus form the encoded knowledge which so many have struggled over the centuries to gain and comprehend.
Alchemy is also in itself an important term. It describes a process of seeking, of transformation and of attainment.
If we are thinking of the term Alchemy we must remember that in addition to there being three realities of existence there are also seven dimensions of nature.
Thus physics and chemistry and the so called hard sciences not only study just the physical reality of existence they also only study substantively only the three dimensions we currently perceive with our untransformed senses.
There are two remaining important issues regarding a working definition of Alchemy.
The one is that Alchemy is not an external process as such. In order for an Alchemist to be able to comprehend the three realities of existence and the seven dimensions of nature, he/she must have a sufficiently transformed psychological perception. Since this transformation is an incremental process, the Alchemist gains access to those realms incrementally. A plethora of techniques (from many ancient and modern traditions and cultures) are available for this purpose. Simple techniques can be used to build consciousness/transformation which then feeds back into access to more powerful and effective techniques, which produce greater transformation/consciousness in turn.
The other one is that there are two sets of elements that an Alchemist works with. The one is listed in the periodic table of the physical elements and the other is the archetype describing the intelligence of creation, that of the elemental forces of Ether, Fire, Air, Water and Earth.
In order for an Alchemist to transform one physical element into another one (for instance lead into gold) he/she must have worked to earn the right to work with the elemental forces of nature, built a stable relationship with them and then achieved the authority to be able to carry out that objective.
These two books are really good places to start delving into the mysteries.
The Red Lion
by Maria Szepes
The Emerald Tablet : Alchemy for Personal Transformation
by Dennis William Hauck