stone in the midst of the froth. The Welsh peasants believe the beads to
possess medicinal virtues of many sorts and to be particularly
efficacious for all maladies of the eyes. In Wales and Ireland the beads
sometimes went by the name of the Magician's or Druid's Glass (_Gleini
na Droedh_ and _Glaine nan Druidhe_). Specimens of them may be seen in
museums; some have been found in British barrows. They are of glass of
various colours, green, blue, pink, red, brown, and so forth, some plain
and some ribbed. Some are streaked with brilliant hues. The beads are
perforated, and in the Highlands of Scotland the hole is explained by
saying that when the bead has just been conflated by the serpents
jointly, one of the reptiles sticks his tail through the still viscous
glass. An Englishman who visited Scotland in 1699 found many of these
beads in use throughout the country. They were hung from children's
necks to protect them from whooping cough and other ailments. Snake
Stones were, moreover, a charm to ensure prosperity in general and to
repel evil spirits. When one of these priceless treasures was not on
active service, the owner kept it in an iron box to guard it against
fairies, who, as is well known, cannot abide iron.[40]

[Medicinal plants, water, are not allowed to touch the earth.]

Pliny mentions several medicinal plants, which, if they were to retain
their healing virtue, ought not to be allowed to touch the earth.[41]
The curious medical treatise of Marcellus, a native of Bordeaux in the
fourth century of our era, abounds with prescriptions of this sort; and
we can well believe the writer when he assures us that he borrowed many
of his quaint remedies from the lips of common folk and peasants rather
than from the books of the learned.[42] Thus he tells us that certain
white stones found in the stomachs of young swallows assuage the most
persistent headache, always provided that their virtue be not impaired