Alchemy (introduction)
His Majesty the Worm · p.229
Open source p.229Alchemy
“That night the King walked late in his chamber in the Iron Tower alone. His jars and flasks and bottles of blue and green and purple glass wherein he kept his cursed drugs and electuaries of secret composition, his athals and athanors, his crucibles, his horsebellied retorts and alembics and bainsmaries, stood arow on shelves coated with dust and hung about with the dull spider's weavings..
The King was deep in his contemplation, with a big black book open before him on the six-sided reading-stand: the damnablest of all his books, the same which had taught him aforetime what he must do when by the wicked power of enchantment
he had wanted but a little to have confounded Demonland
and all the lords thereof in death and ruin.”
– The Worm Ouroboros, E. R. Eddison
Alchemists are thieves. They are thieves of the worst sort.
They steal souls.
By butchering out the gallbladder, the liver, the bufonite, the alchemist distills the essence of a creature. This can only be done in death, of course, because death releases the soul. Distilling these reagents creates an alchemically reactive substance.
This allows the alchemist to use the powers of monsters. At least, for a while.
You can see why this is a vicious cycle.