This section is from the book "The Book Of Talismans, Amulets And Zodiacal Gems", by William Thomas & Kate Pavitt. Also available from Amazon: The book of talismans, amulets and zodiacal gems.
The Etruscans, Greeks And Romans were all familiar with and great believers in the virtues of Talismans and Amulets, a belief based not only on the symbols of their own faith but largely influenced by the beliefs of the surrounding nations, that of the Egyptians being particularly noticeable. Amongst the earliest and most popular Talismans are many Scarab rings with inscriptions cut in the under sides; these were frequently used as seals.
In the course of the amalgamation of beliefs which took place under the Ptolemies, Isis and Osiris were associated with all kinds of Asiatic and Greek gods; but, as time went on, Isis became the most universal goddess, ruling heaven and earth and all Mankind, her worship quickly spreading throughout all the Roman dominions. Her name is usually understood to mean Wisdom, and upon the pavement of her temple was inscribed, "I am everything that has been, and is, and shall be, nor hath any mortal opened my veil".
The most common symbol of Isis was a Crescent Moon, which was worn by Roman women upon their shoes as a safeguard from witchcraft and to prevent the evil spirits of the moon from afflicting them with delusions, hysteria, or lunacy; also to attract the good-will of Isis that they might be successful in love, happy in motherhood, and fortunate in life. From this Crescent symbol (Illustration No. 113, Plate VIII) the Horseshoe undoubtedly became regarded as a Talisman, and as such was used by the Greeks and Romans, who nailed it with the horns upward as a charm against the Plague. In an old publication of 1618 we are instructed that the horseshoe should be nailed upon the threshold to keep Luck within the house and to keep out witches and nullify their evil powers; but in order to obtain the best results the horseshoe must be found by the owner of the house or by a member of the household. In the Middle Ages horseshoes were frequently buried amongst the roots of an Ash tree, which imparted such virtue to the Ash that a twig from it stroked upward over cattle that had been overlooked, charmed away the evil. In Suffolk the fishermen still believe that a horseshoe nailed to the mast of a smack will protect it against bad weather, and their Newfoundland brothers use the horseshoe as a specific against many dangers, especially as a charm to keep away the Devil. In this superstition they resemble the miners of Devon and Cornwall who fix a horseshoe to the mine with the horns upward, it being common knowledge that the Devil travels in a circle and is consequently frustrated in his evil course when he arrives at either of the horns and is obliged to take a retrograde course. To this day, it is still regarded by the country-folk as essential to the well-being of the finder of this charm to suspend it horns upward over the door of his dwelling to hold the luck in, it being thought to run out at each end of the horseshoe if reversed. In Gay's fable of the Old Woman and Her Cats the witch complains:
"Crowds of boys Worry me with eternal noise. Straws laid across my path retards, The Horse shoes nailed each threshold guards. The stunted broom the Wenches hide In fear that I should up and ride".
ETRUSCAN, GREEK, ROMAN, AND ORIENTAL TALISMANS.