Alchemy was that weird branch of science prevalent mostly in the Dark Ages, but later died down. You can find bits and pieces of it still floating around, but only in strange places. So why does it arise in steampunk stories? To answer that, we must first uncover what alchemy is really all about. Alchemy was the science that predated chemistry.

Id like to add that alchemy is closely related to chemistry which meshes well with the sci-fi parts of steampunk fiction. But alchemy also has many roots in the occult and philosophy as mentioned, allowing for easy connections between magic and super science without too much world building.

There are no big changes in the world, aside from the recent use of steam as the main energy source due to an early "energetic" revolution. So, I have this medic/alchemist character, who joins a revolutionary group, and they ask him to use alchemy to create alchemical weapons/gadgets.

I figured the "Punk" part could be about rebelling against the immortals. The oppressive part could be that(Immortals), as well as greedy companies and industries. Also, Alchemy makes people less equal due to the possibility of immortality and wisdom for the wealthy.

It may not be as romantic as turning lead into gold, but I definitely think these sorts of projects qualify as alchemy. Why am I even thinking about this? Steampunk is the intersection of the Maker movement with science fiction aesthetic and a revival of interest in the Victorian.