Imitation Pearl and Coral

FALSE PEARLS.

False pearls are little hollow spheres of glass covered internally with a coating imitating the orient of natural pearls. Their fabrication comprehends two series of operations--the production of the sphere, and the introduction of the coating.

The spheres are produced by the glass-blower, who by aid of an enameller's lamp solders the extremity of a tube having the proper diameter, and blows into the tube when the substance is of the right consistency. In this way very regular little spheres are obtained, that serve for the composition of the ordinary quality of false pearls.

In pearls of great beauty the tube employed is slightly opalescent, and the glass-blower, besides, gives to the little spheres, while they are yet malleable, certain slight perceptible inequalities of surface, by gently tapping them with a small iron bar. This gives them a yet greater resemblance to natural pearls, which are very seldom absolutely regular.

No mention is made in ancient writers of artificial pearls being made, and it is not till we come down to the beginning of the sixteenth century that we find Venice had then established a reputation for this branch of industry.

At first the glass balls were filled with various materials, generally with a base of mercury. But in the year 1680 a rosary-maker named Jacquin conceived the idea of using, in the place of this mercurial mixture, a harmless substance that produced an infinitely more perfect colour.

This substance, the essence of orient, is formed from the scales of the bleak or ablette, a little white fish which abounds in the Seine, the Marne, and the Loiret.

The fishes are rubbed rather roughly in pure water, contained in a large basin; the whole is then strained through a linen cloth, and left for several days to settle, when the water is drawn off. The sediment forms the essence of orient. It requires from 17,000 to 18,000 fishes to obtain 500 grammes (a little over a pound) of this substance.

The scaly substance is liable to decompose quickly, and numerous chemical agents are employed by different manufacturers to preserve it. These means are kept a secret, but it is known that liquid ammonia, or the volatile alkali, is one of the substances most commonly used.

The process of colouring the pearl is commenced by lining the interior of the ball with a delicate layer of perfectly limpid and colourless parchment-glue; and before it is quite dry, the essence of orient is introduced by means of a slender blow-pipe. It is then allowed to dry; the pearl is filled with wax, and, if intended for a necklace, is pierced.

FALSE CORAL.