Alchemy

Alchemy is a field of magic concerned with understanding the composition and structure of substances, along with their physical, chemical, and magical properties, and transmuting these substances by rearranging the components. Because of this, alchemy is deeply connected to transformation branch of Western Magic and potions-making. The most basic tenet of alchemy is the Law of Equivalent Exchange, which states that in order to create something, something of equal value must be loss. That is, an object cannot be conjured from thin air using alchemy and must be made with a starting material with the same mass and ideally physical and chemical properties. Alchemical transmutation relies on the alchemist's magical energy to catalyze the reaction that decomposes the original object into atoms and rearranging these atoms into the new object. While similar feats can be accomplished with transformation magic, the knowledge gained through studying alchemy and performing these basic transmutations pave the way to the creation of the Philosopher's Stone and accomplishing feats impossible with any other form of magic.

Biological alchemy

Biological alchemy deals with alchemical transmutations performed with the aim of creating living things. All known attempts of such transmutations have ended in failure and resulted in massive repercussion to the alchemists. This branch of alchemy has been deemed forbidden and illegal; all records of research and experiments in this field has been collected by the Magic Council and stored away from the public.
The most common experiment were done to revive the dead. Being that the alchemy was associated with Elixir of Life and ordinary dark magic only managed to partially revive people, alchemists theorized about the potential of alchemy for reviving the dead and proceeded to experiment to verify their theories. Needless to say, the experiments were inhuman, and many victims arose from these experiments. Eventually, the Department of Magical Law Enforcement became aware of these experiments, arrested the alchemists, and illegalize all research and practice of biological alchemy.
This does not include spagyric, which the process of making herbal medicine through alchemical procedures.

Soul alchemy

Soul alchemy is a lesser known and theoretical branch of alchemy proposed by the alchemists who sought to push the boundaries. No experiments have been performed to confirm or deny these theories, as all of the writing were done by the same alchemists who attempted to revive the dead unsuccessfully after they were imprisoned.

Inspiration

Alchemy is a protoscience and philosophical practice prevalent in Asia (particularly ancient China) and Europe (during the Middle Ages). Unlike modern science which seeks to explain the world around us, alchemy seeks to create the Elixir of Immortality among other things. Chinese alchemy was embedded in the magical practice of Taoism and focused primarily on the creation of the elixir, whereas medieval European alchemy sought after the Philosopher's Stone, which could produce Elixir of Life, transmute base metal into gold, create panaceas (the cure for all diseases), and develop alkahest (the universal solvent). In Europe, the project to create the Philosopher's Stone was called the magnum opus, and it Is believed that upon completion of the project, not only will the alchemist produce the Stone but also achieve perfection of the human body and soul. In a sense, this is a form of enlightenment where the alchemist comes to complete understanding of themselves and the world around them^[1].
The magnum opus was originally stated to have four stages: nigredo, albedo, citrinitas, and rubedo, which are changes in color corresponding to black, white, yellow, and red^[2]. Thus, the final product, the Philosopher's stone is often portrayed as a red stone. These four stages were expanded upon by George Ripley in the famous Ripley Scroll to include:

1. Calcination
2. Solution (or Dissolution)
3. Separation
4. Conjunction
5. Putrefaction
6. Congelation
7. Cibation
8. Sublimation
9. Fermentation
10. Exaltation
11. Multiplication
12. Projection

Prominent examples of alchemists are Lao Tzu, the founder of Taoism who is believed to have achieved immortality and became a deity through alchemy*, and Nicolas Flamel, who is believed to have created the Philosopher's Stone and achieved immortality as a human.
* Another Chinese philosopher Zou Yan (305-240 BCE) has been associated with the origins of Chinese alchemy and Taoism, a century after Lao Tzu and the forming of the religion.

References

1. ^ Alchemy - Wikipedia. https://en.wikipedia.org/wiki/Alchemy
2. ^ Magnum opus (alchemy) - Wikipedia. https://en.wikipedia.org/wiki/Magnum_opus_(alchemy)