Talk to Alchemist Geroda to receive the mana jar for charging.
Head north out of the city to Thylysium Cemetery. Along with the ‘normal’ denizens of the cemetery (Rats, Undead Legionnaires, and sometimes Wild Boars), there will now be 5 Restless Mana Ghosts floating around.
Kill the 5 Ghosts, then return to Alchemist Geroda for your reward.
You can then talk to him again for the last quest in the chain, Alchemist Jacobas.