Every time a character mentions the philosopher's stone in The Alchemist I can't help but think of Harry Potter. If you don't know the play but know the Potter series then you'll understand why the very idea of the stone's existence gets the characters in The Alchemist excited (and avaricious).
In Ben Jonson's play Subtle (Mark Lockyer), a conman, tricks a rich gentleman and some Anabaptists into believing that he can produce the stone. It is one method that he and his fellow tricksters - Face (Ken Nwosu), a butler and Dol Common (Siobhan McSweeney) a prostitute - use to embezzle money from unsuspecting acquaintances. The house where Face works is the front for their business while his master is out of London avoiding the plague.
The charlatan and his partners have also tricked a gambler into believing they can get him a lucky charm from the fairy queen and a shopkeeper that Subtle can advise on the most propitious design and layout for his new tobacco shop. Of course there is one debunker of 'the alchemist's' powers in the form of Surly who sets about trying to expose him as a thief.