In Tuscany magical medicines are taken upon the threshold, which also plays an important part in sorcery. One reason assigned for this fact is that the threshold forms the line separating the outer world, where demons are rampant, from the domestic precincts, where human beings dwell. One writer affirms it to be a fixed law in demonology that spirits cannot cross the threshold and enter a house unless previously invited to do so, but adds that there are many exceptions to this rule.[192] The weight of evidence does not support this view, for mischievous fairies and witches are known to rudely disregard the laws of etiquette, and do not wait for an invitation to enter dwellings. This fact is, indeed, a chief _raison d’être_ for the use of talismans at the entrance of habitations. The residents of the beautiful Thuringian Forest region, in whose neighborhood these lines chanced to be penned, are wont to affix horse-shoes to the thresholds of their chamber-doors, lest some rude goblin enter and disturb their slumbers. But the fastidiousness of these sylvan folk is not content with an ordinary shoe, even though found on the road and venerable with rust; in order to serve its purpose as a talisman, a Thuringian horse-shoe must have been forged by a bachelor of wholesome life and good character, on Saint John’s Eve.[193] In German households, the horse-shoe over the door is believed to afford protection against divers apparitions, as well as against the Devil, witchcraft, lightning, sickness, and evils of every sort. The cross, symbol of the Christian faith, is the most potent of all talismans, but is seldom seen at the entrance of dwellings. In some Roman Catholic countries the crucifix is, indeed, everywhere conspicuous, not only in churches and shrines, but by the roadside, in fields, and on the outer walls of houses, but it is rarely placed at the front door. In Hungary, however, the Magyars mark with black chalk the figure of a cross upon their stable-doors, and also brand anew thereon the sacred emblem each year at Christmas time. The respect paid by the inhabitants of Tibet to their household divinities somewhat resembles the worship of their _Lares_ by the Romans of old, and finds a parallel in the honor accorded to the favorite amulet of Western civilization, the horse-shoe. The Tibetans set up above the entrances of their houses complex talismans, composed of various mystical objects, such as a ram’s skull with horns attached, having displayed along the base of the skull pieces of carved wood representing a man and woman, a house, and other symbols; the idea being to deceive the demons, and to make them believe that these objects are the real dwelling and its inmates. The Tibetans believe that the demons are thus tricked, and that the wooden images are the victims of their mischievous designs.[194]