"It was one of my more brilliant ideas, and between you and me, that's saying something. You see, only one who wanted to find the Stone -- find it, but not use it -- would be able to get it, otherwise they'd just see themselves making gold or drinking Elixir of Life. My brain surprises even me sometimes...."
-- Albus Dumbledore (PS17)
Alchemy is the ancient study of transforming base metals into gold and eventually creating a Philospher’s Stone which would give the owner eternal life. Because metals must be melted and mixed before they are transformed into gold, alchemy is a cross between Potions and Transfiguration.
The most famous alchemist in the Wizarding World was Nicholas Flamel, the partner of Albus Dumbledore in the search for the seven uses of Dragon’s Blood (PS6). Flamel possessed the Philosopher’s Stone which allowed he and his wife Perenelle to live for hundreds of years. After Lord Voldemort sought to possess the stone, it was destroyed, and the Flamels passed away (PS17).
Other alchemists mentioned on Chocolate Frog Cards are Cornelius Agrippa and Paracelsus (PS6).
- Alchemy is offered as a class at Hogwarts in years 6 and 7, though Hermione chose not to take it after what they had been through to get the stone from Quirrel-Mort (Pm).
- J.K. Rowling wrote that Hagrid and Dumbledore represented an alchemical mixture of opposites as father-figures for Harry. "Rubeus" means red and "Albus" means white, which were colors symbolic of base metals and gold (Pm).
- Harry recieves a Chocolate Frog Card of Paracelsus on his first train ride to Hogwarts (PS6). A statuary bust of Paracelsus was found in a Hogwarts corridor where Peeves was threatening to drop it on someone's head, and Nearly Headless Nick hoped the Blood Baron could stop him (OP14). So it is probably the same statue stashed in the Room of Requirement when Harry hid the original Half-Blood Prince Potions Book in a cupboard underneath (HBP24).
- While searching for the horcruxes, Harry realized he had seen the diadem of Rowena Ravenclaw on top of the bust of Paracelsus. Both statue and tiara were destroyed by Crabbe's Fiendfyre during the Battle of Hogwarts (DH31).
In alchemy, metals can be turned into potions then into the Philosopher's Stone.
from Greek khēmia "pouring metals"
"One interpretation of the 'instructions' left by the alchemists is that they are symbolic of a spiritual journey, leading the alchemist from ignorance (base metal) to enlightenment (gold)." J.K. Rowling (Pm)
Nicholas Flamel was a real man who lived in Paris with his wife Perenelle from about 1330-1418. In the 1700's, scientist Sir Isaac Newton mentioned his alchemical works and drawings in his journals, and thus the legend of the "immortal" Flamel was born. Flamel was also mentioned in Victor Hugo's The Hunchback of Notre Dame. source: Wikipedia
J.K. Rowling said that while writing Harry Potter and the Philosopher's Stone she had a dream about Flamel:
"I remember having a higly detailed and exceptionally vivid dream . . . which was like a renaissance painting come to life. Flamel was leading me around his cluttered laboratory, which was bathed in golden light, and showing me exactly how to make the Stone (I wish I could remember how to do it) (Pm).
As an alchemist, Paracelsus was less interested in the Philosopher's Stone and more interested in using chemicals and plants as medicine. Born Philippus Aureolus Theophrastus Bombastus von Hohenheim, he lived in Switzerland from 1493-1541 (wikipedia). He wrote a book called Treasure of Treasures of the Alchemists.
Heinrich Cornelius Agrippa von Nettesheim (1486-1535), was a physician and writer living in France and Germany. He is most famous for his book on Occult Philosophy (source: Wikipedia).
From the Web
The Philosopher's Stone on Pottermore
"Alchemy" on Pottermore
"Alchemy" on the Harry Potter Wiki