The mode of obtaining coral is by a very simple machine, consisting of two strong bars of wood or iron tied across each other, with a weight suspended from their centre of union. Each of the arms is loosely surrounded, through its whole length, with twisted hemp; and, at the extremity, there is a small open purse or net. This machine is suspended by a rope, and dragged along those rocks where the coral is most abundant; and such as is broken off either becomes entangled in the hemp, or falls into the nets. Coral is bought by weight: and its value increases in a certain ratio according to its size. Beads of large size are worth about forty shillings an ounce, whilst small ones do not sell for more than four shillings. Large pieces of coral are sometimes cut into balls, and exported to China, to be worn in the caps of certain persons, as an insignia of office. These, if perfectly sound and of good colour, and upwards of an inch in diameter, have been known to produce, in that market, as much as 300l. to 400l. sterling each. There are extant many beautiful pieces of sculpture in coral; as this substance has in all ages been considered an admirable material on which to exhibit the artist's taste and skill. Probably the finest specimens of sculptured coral that are known are a chess-board and men, in the Tuilleries. The Chinese have, within the last three or four years, succeeded in cutting coral beads of much smaller dimension than has hitherto been effected by any European artist. These, which are not larger than small pins' heads, are called _seed coral_, and are now imported from China into this country in very considerable quantity for necklaces. Nearly the whole of the coral that is used is of _red_ colour; _white coral_ being considered of little value either as an article of commerce or decoration. There are modes of imitating coral so exactly, that, without a close inspection, it is sometimes impossible to discover the difference betwixt the real and the counterfeit article. 281. _SPONGE_ (Spongia officinalis) _is an animal substance of soft, light, porous, and elastic nature, which is found adhering to rocks at the bottom of the sea in several parts of the Mediterranean, and particularly near the islands of the Grecian Archipelago._