Some of these incantations have already come before our notice, and probably some of the verses which Cæsar says the Druids would not commit to writing were of the nature of spells.1072 The virtue of the spell lay in the spoken formula, usually introducing the name of a god or spirit, later a saint, in order to procure his intervention, through the power inherent in the name. Other charms recount an effect already produced, and this, through mimetic magic, is supposed to cause its repetition. The earliest written documents bearing upon the paganism of the insular Celts contain an appeal to "the science of Goibniu" to preserve butter, and another, for magical healing, runs, "I admire the healing which Diancecht left in his family, in order to bring health to those he succoured." These are found in an eighth or ninth century MS., and, with their appeal to pagan gods, were evidently used in Christian times.1073 Most Druidic magic was accompanied by a spell—transformation, invisibility, power over the elements, and the discovery of hidden persons or things. In other cases spells were used in medicine or for healing wounds. Thus the Tuatha Dé Danann told the Fomorians that they need not oppose them, because their Druids would restore the slain to life, and when Cúchulainn was wounded we hear less of medicines than of incantations used to stanch his blood.1074 In other cases the Druid could remove barrenness by spells.
The survival of the belief in spells among modern Celtic peoples is a convincing proof of their use in pagan times, and throws light upon their nature. In Brittany they are handed down in certain families, and are carefully guarded from the knowledge of others. The names of saints instead of the old gods are found in them, but in some cases diseases are addressed as personal beings. In the Highlands similar charms are found, and are often handed down from male to female, and from female to male. They are also in common use in Ireland. Besides healing diseases, such charms are supposed to cause fertility or bring good luck, or even to transfer the property of others to the reciter, or, in the case of darker magic, to cause death or disease.1075 In Ireland, sorcerers could "rime either a man or beast to death," and this recalls the power of satire in the mouth of File or Druid. It raised blotches on the face of the victim, or even caused his death.1076 Among primitive races powerful internal emotion affects the body in curious ways, and in this traditional power of the satire or "rime" we have probably an exaggerated reference to actual fact. In other cases the "curse of satire" affected nature, causing seas and rivers to sink back.1077 The satires made by the bards of Gaul, referred to by Diodorus, may have been believed to possess similar powers.1078 Contrariwise, the Filid, on uttering an unjust judgment, found their faces covered with blotches.1079
A magical sleep is often caused by music in the sagas, e.g. by the harp of Dagda, or by the branch carried by visitants from Elysium.1080 Many "fairy" lullabies for producing sleep are even now extant in Ireland and the Highlands.1081 As music forms a part of all primitive religion, its soothing powers would easily be magnified. In orgiastic rites it caused varying emotions until the singer and dancer fell into a deep slumber, and the tales of those who joined in a fairy dance and fell asleep, awaking to find that many years had passed, are mythic extensions of the power of music in such orgiastic cults. The music of the Filid had similar powers to that of Dagda's harp, producing laughter, tears, and a delicious slumber,1082 and Celtic folk-tales abound in similar instances of the magic charm of music.
We now turn to the use of amulets among the Celts. Some of these were symbolic and intended to bring the wearer under the protection of the god whom they symbolised. As has been seen, a Celtic god had as his symbol a wheel, probably representing the sun, and numerous small wheel discs made of different materials have been found in Gaul and Britain.1083 These were evidently worn as amulets, while in other cases they were offered to river divinities, since many are met with in river beds or fords. Their use as protective amulets is shown by a stele representing a person wearing a necklace to which is attached one of these wheels. In Irish texts a Druid is called Mag Ruith, explained as magus rotarum, because he made his Druidical observations by wheels.1084 This may point to the use of such amulets in Ireland. A curious amulet, connected with the Druids, became famous in Roman times and is described by Pliny. This was the "serpents' egg," formed from the foam produced by serpents twining themselves together. The serpents threw the "egg" into the air, and he who sought it had to catch it in his cloak before it fell, and flee to a running stream, beyond which the serpents, like the witches pursuing Tam o' Shanter, could not follow him. This "egg" was believed to cause its owner to obtain access to kings or to gain lawsuits, and a Roman citizen was put to death in the reign of Claudius for bringing such an amulet into court. Pliny had seen this "egg." It was about the size of an apple, with a cartilaginous skin covered with discs.1085 Probably it was a fossil echinus, such as has been found in Gaulish tombs.1086 Such "eggs" were doubtless connected with the cult of the serpent, or some old myth of an egg produced by serpents may have been made use of to account for their formation. This is the more likely, as rings or beads of glass found in tumuli in Wales, Cornwall, and the Highlands are called "serpents' glass" (glain naidr), and are believed to be formed in the same way as the "egg." These, as well as old spindle-whorls called "adder stones" in the Highlands, are held to have magical virtues, e.g. against the bite of a serpent, and are highly prized by their owners.1087
Pliny speaks also of the Celtic belief in the magical virtues of coral, either worn as an amulet or taken in powder as a medicine, while it has been proved that the Celts during a limited period of their history placed it on weapons and utensils, doubtless as an amulet.1088 Other amulets—white marble balls, quartz pebbles, models of the tooth of the boar, or pieces of amber, have been found buried with the dead.1089 Little figures of the boar, the horse, and the bull, with a ring for suspending them to a necklet, were worn as amulets or images of these divine animals, and phallic amulets were also worn, perhaps as a protection against the evil eye.1090
A cult of stones was probably connected with the belief in the magical power of certain stones, like the Lia Fail, which shrieked aloud when Conn knocked against it. His Druids explained that the number of the shrieks equalled the number of his descendants who should be kings of Erin.1091 This is an ætiological myth accounting for the use of this fetich-stone at coronations. Other stones, probably the object of a cult or possessing magical virtues, were used at the installation of chiefs, who stood on them and vowed to follow in the steps of their predecessors, a pair of feet being carved on the stone to represent those of the first chief.1092 Other stones had more musical virtues—the "conspicuous stone" of Elysium from which arose a hundred strains, and the melodious stone of Loch Láig. Such beliefs existed into Christian times. S. Columba's stone altar floated on the waves, and on it