What magical healing present did Lucy receive in The Chronicles of Narnia the lion the witch and the wardrobe?

A cordial made from the juice of the Fireflower which grows on the mountains of the sun. It could not bring dead people to life or replace missing appendages, but it could cure seasickness, heal flesh wounds, and other illnesses. Trumpkin comments in "Prince Caspian" that Lucy must be a master surgeon with this cordial.