Here is the full list of all 18 Alchemist achievements.
Reach the first lantern.
Reach the thirtieth lantern.
Create a potion.
Create fifty potions.
Create one of each type of potions.
Make somebody angry.
Complete the game without making anyone angry.
Complete the game while making everybody angry.
Stun the monster.
Stun ten monsters.
Stun fifty monsters.
Stun seven enemies with a single explosion.
Catch a mouse.
Catch a firefly.
Save the character from the tower.
Create the Philosopher's Stone.
Steal a recipe from the tower.
Defeat the Mage.