From Lady Wilde, Ancient Legends of Ireland, pages 142-43:
he Siodh-Dune, or the Mount of Peace, is also a favorite resort of the fairies. It is an ancient, sacred place, where the Druids in old time used to retire to pray, when they desired solitude; and the fairies meet there every seven years to perform the act of lamentation and mourning for having been cast out of heaven.
Earth, lake, and hill are peopled by these fantastic, beautiful gods of earth; the wilful, capricious child-spirits of the world. The Irish seem to have created this strange fairy race after their own image, for in all things they strangely resemble the Irish character.
The Sidhe passionately love beauty and luxury, and hold in contempt all the mean virtues of thrift and economy. Above all things they hate the close, niggard hand that gathers the last grain, and drains the last drop in the milk-pail, and plucks the trees bare of fruit, leaving nothing for the spirits who wander by in the moonlight. They like food and wine to be left for them at night, yet they are very termprate; no one ever saw an intoxicated fairy.
But people should not sit up too late; for the fairies like to gather round the smouldering embers after the family are in bed, and drain the wine-cup, and drink the milk which a good housewife always leaves for them, in case the fairies should come in and want their supper. A vessel of pure water should also be left for them to bathe in, if they like it. And in all things the fairies are fond of being made much of, and flattered and attended to; and the fairy blessing will come back in return to the giver for whatever act of kindness he has done to the spirits of the hill and the cave. Some unexpected good fortune or stroke of luck will come upon his house or his children; for the fairy race is not ungrateful, and is powerful over man both for good and evil.
Therefore be kind to the wayfarer, for he may be a fairy prince in disguise, who has come to test the depth of your charity, and of the generous nature that can give liberally out of pure love and kindliness to those who are in need, and not in hope of a reward.
If treated well, the fairies will discover the hidden pot of gold, and reveal the mysteries of herbs, and give knowledge to the fairy women of their mystic spells that can cure disease, and save life, and make the lover loved.
All they ask in return is to be left in quiet possession of the rath and the hill and the ancient hawthorn trees that have been theirs from time immemorial, and where they lead a joyous life with music and dance, and charming little suppers of the nectar of flowers, down in the crystal caves, lit by the diamonds that stud the rocks.
But some small courtesies they require. Never drain your wine-glass at a feast, nor the poteen flask, nor the milk-pail; and never rake out all the fire at night, it looks mean, and the fairies like a little of everything going, and to have the hearth comfortable and warm when they come in to hold a council after all the mortal people have gone to bed. In fact, the fairies are born aristocrats, true ladies and gentlemen, and if treated with proper respect are never in the least malignant or ill-natured.
All the traditions of the fairies show that they love beauty and splendour, grace of movement, music and pleasure; everything, in fact, that is artistic, in contradistinction to violent, brutal enjoyment. Only an Aryan people, therefore, could have invented the Sidhe race.