The ceremonial core of "need-fire" was to kindle the new fire to purify and fertilize the commu-nity, and to prolong these benefits by using the need-fire to rekindle the hearth fires. From the need-fire the participants ignited a great bonfire. Into it they sometimes threw effigies of witches, or burned animals like cattle or witch-identified creatures like cats. ("Bonfire" derives from bone-fire.) Through the bonfire's smoke, and over its ebbing flames or coals, they passed their flocks?cattle stricken by murrain, most commonly, but also pigs, geese, and horses in set order. Then they passed through themselves. Next they carried the flame and smoke with torches through the countryside; their fields, orchards, and pastures. The ashes were sometimes scattered over the ground, and sometimes pressed over their faces. They carried the embers or tapers to their homes to re-ignite the hearth, and kept the e xtinguished brand in the house as a talisman against lightning, wildfire, and witchcraft.
Lady Wilde provides a remarkably full account of the Midsummer's fire as it persisted in nineteenth-century Ireland.
The sacred fire was lighted with great ceremony on Midsummer Eve; and on that night all the people of the adjacent country kept fixed watch on the western promontory of Howth, and the moment the first flash was seen from that spot the fact of ignition was announced with wild cries and cheers repeated from village to village, when all the local fires began to blaze, and Ireland was circled by a cordon of flame rising up from every hill. Then the dance and song began round every fire, and the wild hurrahs filled the air with the most frantic revelry. Many of these ancient customs are still continued, and the fires are still lighted on St. John's Eve on every hill in Ireland. When the fire has burned down to a red glow the young men strip to the waist and leap over or through the flames; this is done backwards and forwards several times, and he who braves the greatest blaze is considered the victor over the powers of evil, and is greeted with tremendous applause. When the fire burns still lower the young girls leap the flame, and those who leap clean over three times back and forward will be certain of a speedy marriage and good luck in after-life, with many children. The married women then walk through the lines of the burning embers; and when the fire is nearly burnt and trampled down, the yearling cattle are driven through the hot ashes, and their back is singed with a lighten hazel twig. These rods are kept safely afterwards, being considered of immense power to drive the cattle to and from the watering places. As the fire diminishes the shouting grows fainter, and the song and dance commence; while professional story-tellers narrate tales of fairy-land, or of the good old times long ago, when the kings and princes of Ireland dwelt amongst their own people, and there was food to eat and wine to drink for all comers to the feast at the king's house. When the crowd at length separate, every one carries home a brand from the fire, and great virtue is attached to the lighted brone which is safely carried to the house without breaking or falling to the ground. Many contests also arise amongst the young men; for whoever enters his house first with the sacred fire brings the good luck of the year with him. ? Ancient Legends, Mystic Charms, and Superstitions of Ireland , Lady Wilde. 1887.