There are seven herbs of great value and power; they are ground ivy, vervain, eyebright, groundsel, foxglove, the bark of the elder-tree, and the young shoots of the hawthorn.
Nine balls of these mixed together may be taken, and afterwards a potion made of bog-water and salt, boiled in a vessel, with a piece of money and an elf-stone. The elf-stone is generally found near a rath; it has great virtues, but being once lifted up by the spade it must never again touch the earth, or all its virtue is gone. (This elf-stone is in reality only an ancient stone arrow-head.)
The Mead Cailleath, or wood anemone, is used as a plaister for wounds.
The hazel-tree has many virtues. It is sacred and powerful against devils’ wiles, and has mysteries and secret properties known to the wise and the adepts. The ancient Irish believed that there were fountains at the head of the chief rivers of Ireland, over each of which grew nine hazel-trees that at certain times produced beautiful red nuts. These nuts fell on the surface of the water, and the salmon in the river came up and ate of them, which caused the red spots on the salmon. And whoever could catch and eat one of these salmon would be indued with the sublimest poetic intellect. Hence the phrase current amongst the people: “Had I the net of science;” “Had I eaten of the salmon of knowledge.” And this supernatural knowledge came to the great Fionn through the touch of a salmon, and made him foreknow all events.
Of all herbs the yarrow is the best for cures and potions. It is even sewn up in clothes as a preventive of disease.
The Liss-more, or great herb, has also strong healing power, and is used as a charm.