Again, in respect of the healing virtues of mistletoe the opinion of modern peasants, and even of the learned, has to some extent agreed with that of the ancients. The Druids appear to have called the plant, or perhaps the oak on which it grew, the all-healer; and all-healer is said to be still a name of the mistletoe in the modern Celtic speech of Brittany, Wales, Ireland, and Scotland. On St. John's morning (Midsummer morning) peasants of Piedmont and Lombardy go out to search the oak-leaves for the oil of St. John, which is supposed to heal all wounds made with cutting instruments. Originally, perhaps, the oil of St. John was simply the mistletoe, or a decoction made from it. For in Holstein the mistletoe, especially oak-mistletoe, is still regarded as a panacea for green wounds and as a sure charm to secure success in hunting; and at Lacaune, in the south of France, the old Druidical belief in the mistletoe as an antidote to all poisons still survives among the peasantry; they apply the plant to the stomach of the sufferer or give him a decoction of it to drink. Again, the ancient belief that mistletoe is a cure for epilepsy has survived in modern times not only among the ignorant but among the learned. Thus in Sweden persons afflicted with the falling sickness think they can ward off attacks of the malady by carrying about with them a knife which has a handle of oak mistletoe; and in Germany for a similar purpose pieces of mistletoe used to be hung round the necks of children. In the French province of Bourbonnais a popular remedy for epilepsy is a decoction of mistletoe which has been gathered on an oak on St. John's Day and boiled with rye-flour. So at Bottesford in Lincolnshire a decoction of mistletoe is supposed to be a palliative for this terrible disease. Indeed mistletoe was recommended as a remedy for the falling sickness by high medical authorities in England and Holland down to the eighteenth century.
However, the opinion of the medical profession as to the curative virtues of mistletoe has undergone a radical alteration. Whereas the Druids thought that mistletoe cured everything, modern doctors appear to think that it cures nothing. If they are right, we must conclude that the ancient and widespread faith in the medicinal virtue of mistletoe is a pure superstition based on nothing better than the fanciful inferences which ignorance has drawn from the parasitic nature of the plant, its position high up on the branch of a tree seeming to protect it from the dangers to which plants and animals are subject on the surface of the ground. From this point of view we can perhaps understand why mistletoe has so long and so persistently been prescribed as a cure for the falling sickness. As mistletoe cannot fall to the ground because it is rooted on the branch of a tree high above the earth, it seems to follow as a necessary consequence that an epileptic patient cannot possibly fall down in a fit so long as he carries a piece of mistletoe in his pocket or a decoction of mistletoe in his stomach. Such a train of reasoning would probably be regarded even now as cogent by a large portion of the human species.
Again the ancient Italian opinion that mistletoe extinguishes fire appears to be shared by Swedish peasants, who hang up bunches of oak-mistletoe on the ceilings of their rooms as a protection against harm in general and conflagration in particular. A hint as to the way in which mistletoe comes to be possessed of this property is furnished by the epithet thunder-bosom, which people of the Aargau canton in Switzerland apply to the plant. For a thunder-besom is a shaggy, bushy excrescence on branches of trees, which is popularly believed to be produced by a flash of lightning; hence in Bohemia a thunder-besom burnt in the fire protects the house against being struck by a thunder-bolt. Being itself a product of lightning it naturally serves, on homoeopathic principles, as a protection against lightning, in fact as a kind of lightning-conductor. Hence the fire which mistletoe in Sweden is designed especially to avert from houses may be fire kindled by lightning; though no doubt the plant is equally effective against conflagration in general.
Again, mistletoe acts as a master-key as well as a lightning-conductor; for it is said to open all locks. But perhaps the most precious of all the virtues of mistletoe is that it affords efficient protection against sorcery and witchcraft. That, no doubt, is the reason why in Austria a twig of mistletoe is laid on the threshold as a preventive of nightmare; and it may be the reason why in the north of England they say that if you wish your dairy to thrive you should give your bunch of mistletoe to the first cow that calves after New Year's Day, for it is well known that nothing is so fatal to milk and butter as witchcraft. Similarly in Wales, for the sake of ensuring good luck to the dairy, people used to give a branch of mistletoe to the first cow that gave birth to a calf after the first hour of the New Year; and in rural districts of Wales, where mistletoe abounded, there was always a profusion of it in the farmhouses. When mistletoe was scarce, Welsh farmers used to say, No mistletoe, no luck; but if there was a fine crop of mistletoe, they expected a fine crop of corn. In Sweden mistletoe is diligently sought after on St. John's Eve, the people believing it to be, in a high degree, possessed of mystic qualities; and that if a sprig of it be attached to the ceiling of the dwelling-house, the horse's stall, or the cow's crib, the Troll will then be powerless to injure either man or beast.