An Anglo-Saxon treatise on the medical art, from the beginning of the tenth century, the original manuscript of which was owned by an Anglo-Saxon leech named Bald, as testified to by an entry on the title-leaf, gives the agate a prominent place as a talismanic and curative agent. More especially is its power over the demon-world emphasized.
Indeed it is asserted to serve as a sort of diagnostic of demoniacal possession, the words being: “The man who hath in him secretly the loathly fiend, if he taketh in liquid any portion of the shavings of this stone, then soon is exhibited manifestly in him that which before secretly lay hid.” Less unfamiliar to those acquainted with the early literature on the subject are the statements that the wearers of agates were guarded against danger from lightning, and from venom. The liquid “extract of agate,” taken internally, also produced smooth skin and rendered the partaker immune from the bites of snakes.

An extremely strange type of amulets found occasionally in Gallic sepulchres are disks made from human skulls. It appears to be a well-ascertained fact that the operation of trephining was performed at this early date, almost if not quite exclusively in the case of infants, and it is believed principally for the cure of epilepsy. If the child survived the operation its skull was thought to have acquired a certain magic power. This idea had its rise in the belief that epilepsy was the result of an indwelling evil spirit, so that if the disease disappeared as a result or sequence of the operation, this evil spirit was believed to have made his way out through the aperture. On the eventual death of one whose skull had been successfully trephined, disks were sometimes cut just on the edge of the opening through which the possessing spirit had slipped out, leaving as a trace of his passage some of his diabolic but still potent virtue. That the superstition regarding these cranial disks lasted well into the sixteenth century, even among some of the educated, is proven by the fact that on a bracelet which belonged to and was worn by Catherine de’ Medici, one of the talismans was a piece of a human skull.

Attention was first called to the strange amulets taken from the human skull by the operation of trephining, by M. Prunetiere, at a meeting of the French Association for the Advancement of Science, held in Lyons in 1873. The specimen he then exhibited came from a sepulture in the department of Lozere. This particular example showed a break on the edge, and M. Paul Broca has conjectured that a small piece may have been chipped off, so that it might be pulverized and administered as a powder to persons suffering from disease of the brain, a treatment favored by those who doubted the generally-believed supernatural origin of epilepsy, and suspected its source in some lesion of the brain or of the meninges. For this, of course, no more efficient remedy could suggest itself, according to the old sympathetic theory of medicines, than a powder made from the skull of one who had been an epileptic. These skull-amulets have been unearthed in neolithic burials in various parts of France, a considerable number having been found by M. de Baye and others in the department of Marne; a specimen was also found in an Algerian sepulture by General Faidherbe.

The great Greek physician Hippocrates of Cos, a contemporary of Plato, advised that resort should be had to the operation of trephining in many cases of injury to the head, and that the ancient Hindus were to a certain extent familiar with it as a method of treating diseases of the brain appears in one of the Buddhist recitals from a Tibetan source. Here it is related that Atreya, master of the King of Physicians, Jivaka, when appealed to for help by a man suffering from a distressful cerebral disorder, directed the man to dig a pit and fill it up with dung; he then thrust the man into this soft and savory mass until nothing but his head and neck protruded, and opened his skull. From it was drawn out a reptile whose presence had caused the malady. Jivaka seems to have been in consultation with his master in this interesting operation, and is said to have later extracted a centipede from a man’s skull after making an aperture therein with a golden knife. In neither of these cases, however, do we have any hint that disks or fragments from the human skull were used as amulets.

A ghastly object much favored in France in the Middle Ages, as it was believed to give the owner the power to discover hidden treasures, was the so-called main-de-gloire, or “hand of glory,” which was the desiccated hand of one who had met his death by hanging.

A remarkable talismanic bracelet owned by Catherine de’ Medici was set with a skull-fragment and with a representation of a “main-de-gloire.” This is described in the catalogue made in 1786 of M. d’Ennery’s collection. The settings of the bracelet, ten in number, comprised the following objects, to each of which was probably ascribed some special significance and virtue.

An oval “eagle-stone” (aetites), on which was graven in intaglio a winged dragon; above this figure was the date 1559, the year in which the bracelet was composed and that of the death of Catherine’s husband, Henri II.

An octagonal agate, traversed by a number of tubular apertures, the orifices of which could be seen on either side of the stone.

A very fine oval onyx of three colors, bearing graven on its edge the following names of angels: Gabriel, Raphael, Michael, Uriel.

A large oval turquoise with a gold band.

A piece of black and white marble.

An oval brown agate, with a caduceus, a star and a crescent engraved in intaglio on one of its faces, and on its edge the name Jehovah and certain talismanic characters; on the other face were figured the constellation Serpens, the zodiacal sign Scorpio and the Sun, around which were the six planets.

An oblong section of a human skull.

A rounded piece of gold on the convex side of which was graven in relief the “hand of glory” (main-de-gloire); on the concave side appeared the Sun and Moon done in repousse work.

A perfectly round onyx, bearing graven in the centre the name or word “Publeni”; this possibly designated the original Roman owner of the stone.