illustrate the curious fact that the oyster has the habit of forcing intruders out, not manlike through the door, but through the walls of its house. The way of it is this: while the successive coverings of nacre are deposited on the inside of the shell, the outside of the shell is gradually decaying and crumbling away, so that as the wall inside the alien object becomes thicker, the part outside becomes thinner, till finally the intruder reaches the surface—is literally forced through the shell of the oyster.
The pearl is the one gem that comes to us perfect from the hand of Nature, and to this its great antiquity as a gem is largely due. Precious stones whose beauty and brilliance depend on polishing and cutting would naturally be discovered and utilized later. The discovery of the diamond, for instance, probably dates within historic times. Though known earlier, it was not generally included among the gem treasures of royalty even as late as the seventh century. The modern cutting of diamonds in regular facets was invented as recently as 1456. Indeed, it is quite probable that the pearl was the first gem known and treasured by prehistoric man—since the search for food must have been the first occupation of the earliest of the race, and the shining pearl would thus have been discovered in river mussels if not in marine oysters. Certain it is that the Old Testament and the, most ancient written histories allude to pearls, and that remoter evidence is found in the tombs and excavated cities of still earlier eras. The Egyptians, Babylonians and Assyrians held the pearl in an esteem verging on reverence.
Not only were pearls known and prized as the most precious of gems, but they were gathered and treasured in astonishing quantities by the early Oriental potentates. Many relics and records of those days remain. The crown of the Khan of the Tartars, captured on the Oxus by the Persians in the fifth century, was decorated with several thousand pearls. The famous crown of Chosroes, made in the sixth century, and which was strangely concealed for a thousand years in an obscure fortress among the Lauristanian Mountains, till brought to light by Shah Abbas, is incrusted with pearls in conjunction with rubies. In the seventh century the Arabs captured from the Persian nobles fabrics of amazing richness, among which was one marvelous carpet of white brocade, four hundred and fifty feet by ninety feet, with a border worked in precious stones to represent a garden of all kinds of beautiful flowers—the leaves of emeralds and other green gems, the buds and blossoms of pearls, along with rubies and sapphires.
The treasures of the Turkish nobility during some of the more brilliant reigns of the empire seem to belong to fable rather than to veritable history. Sinan Pasha, dying at eighty, left fifteen