Next to your health and mana globes, you will find little potions. These potions can carry around extra mana and health for you when you run around. To fill up these potions, you can play mini-games or you can purchase refills from Hilda Brewer in the Wizard City Fairegrounds.
Those flasks are called potions and they instantly refill you health and mana. There are two ways to refill the potions, one is to play mini games, you just step on one of the sigils. You want to make sure that the potion is completely filled with a cork on top, or else you can't use it. The other way is the buy the refills from Hilda Brewer with gold, which gradually gets more expensive as you level up and earn more potion bottles. Also, know that energy can NOT be filled with potions, they need either time or crowns. :)