This document summarizes several Celtic potions and their purported effects: a fume made of various seeds and roots that is said to induce prophesying; a powder made from elder flowers that claims to make one seem youthful if taken daily for a month; gathering fern seed at midnight on Midsummer's Eve to become invisible; using quicksilver and egg white to detect thieves by making their eyes water; and applying a mixture of milk, honey and fennel seed twice daily to improve hair growth.