Connected with the cult of stones are magical observances at fixed rocks or boulders, regarded probably as the abode of a spirit.  These observances are in origin pre-Celtic, but were practised by the Celts.  Girls slide down a stone to obtain a lover, pregnant women to obtain an easy delivery, or contact with such stones causes barren women to have children or gives vitality to the feeble.  A small offering is usually left on the stone.[1146] Similar rites are practised at megalithic monuments, and here again the custom is obviously pre-Celtic in origin.  In this case the spirits of the dead must have been expected to assist the purposes of the rites, or even to incarnate themselves in the children born as a result of barren women resorting to these stones.[1147] Sometimes when the purpose of the stones has been forgotten and some other legendary origin attributed to them, the custom adapts itself to the legend.  In Ireland many dolmens are known, not as places of sepulture, but as “Diarmaid and Grainne’s beds”—­the places where these eloping lovers slept.  Hence they have powers of fruitfulness and are visited by women who desire children.  The rite is thus one of sympathetic magic.

Holed dolmens or naturally pierced blocks are used for the magical cure of sickness both in Brittany and Cornwall, the patient being passed through the hole.[1148] Similar rites are used with trees, a slit being often made in the trunk of a sapling, and a sickly child passed through it.  The slit is then closed and bound, and if it joins together at the end of a certain time, this is a proof that the child will recover.[1149] In these rites the spirit in stone or tree was supposed to assist the process of healing, or the disease was transferred to them, or, again, there was the idea of a new birth with consequent renewed life, the act imitating the process of birth.  These rites are not confined to Celtic regions, but belong to that universal use of magic in which the Celts freely participated.

Since Christian writers firmly believed in the magical powers of the Druids, aided however by the devil, they taught that Christian saints had miraculously overcome them with their own weapons.  S. Patrick dispelled snow-storms and darkness raised by Druids, or destroyed Druids who had brought down fire from heaven.  Similar deeds are attributed to S. Columba and others.[1150] The moral victory of the Cross was later regarded also as a magical victory.  Hence also lives of Celtic saints are full of miracles which are simply a reproduction of Druidic magic—­controlling the elements, healing, carrying live coals without hurt, causing confusion by their curses, producing invisibility or shape-shifting, making the ice-cold waters of a river hot by standing in them at their devotions, or walking unscathed through the fiercest storms.[1151] They were soon regarded as more expert magicians than the Druids themselves.  They may have laid claim to magical powers, or perhaps they