For some reason for which I have no evidence or explanation, alchemy puts me in mind of Merlin.
Did you ever see the BBC show Merlin? I never watched it religiously, but caught eps here and there. In the show, Merlin’s mentor is Gaius, who knows about magic-y stuff, but his actual job is as a physician. It’s all a bit alchemy-ish.
Alchemy is an influential philosophical tradition whose practitioners have, from antiquity, claimed it to be the precursor to profound powers. The defining objectives of alchemy are varied; these include the creation of the fabled philosopher’s stone, the ability to transform base metals into the noble metals, gold or silver; and the elixir of life, which confers youth and longevity. Western alchemy is recognized as a protoscience that contributed to the development of modern chemistry and medicine. Alchemists developed a framework of theory, terminology, experimental process and basic laboratory techniques that are still recognizable today. But alchemy differs from modern science in the inclusion of Hermetic principles and practices related to mythology, magic, religion, and spirituality.
http://en.wikipedia.org/wiki/Alchemy
The show already has the science vs magic theme, and alchemy is sort of like a bridge between the two.
But I gues alchemy might be connected with witchraft. Rumple is using very often potion. Now I wonder if he is able to do some kind of alchemy or we might already seen him doing some of it.
Rumple turning straw into gold is very much like alchemy. Maybe he took that basic alchemical principal of turning metals into gold, and worked out some magic to tweak it so it worked with straw.