CORK, the bark of a tree of the same name, Quercus Suber, Lin. See QUERCUS, BOTANY Index.
To take off the bark, an incision is made from the top to the bottom of the tree, and at each extremity another round the tree, perpendicular to the first. When the tree is 15 years old, it may be barked for eight years successively; and the quality of the bark improves with the age of the tree. When stripped from the tree, which does not therefore die, the bark is piled up in a pond or ditch, and loaded with heavy stones to flatten it, and reduce it into tables: hence it is removed to be dried; and when sufficiently dry, put in bales for carriage. If care be not taken to strip the bark,
bark, it splits and peels of itself; being pushed up by another bark formed underneath.
The cork-tree, as well as the uses to which the bark is applied, was known both to the Greeks and Romans. Pliny informs us that the Romans employed it to stop all kinds of vessels; but the use of it for this purpose does not appear to have been very common till the invention of glass bottles, of which, according to Professor Beckman, there is no mention before the 15th century.
Other vegetable productions have been sometimes employed instead of cork. The Spondias Lutea, a tree which grows in South America, particularly in moist places, and which is there called monbin or monbain, is sometimes brought to England for the purpose of stopping vessels. The roots of liquorice are applied to the same use, and on that account, this plant is much cultivated in Slavonia, and exported to other countries. A tree called nyssa, which grows in North America, has been found also to answer as a substitute for cork.
The chief use of cork is, to put in shoes, slippers, &c. and to stop bottles. The Spaniards burn it to make that kind of light black called Spanish black, which is used by painters. The Egyptians made coffins of cork; which being lined with a resinous composition, preserved dead bodies uncorrupted. The Spaniards line stone walls with it, which not only renders them very warm, but corrects the moisture of the air.
Fossil Cork, a name given to a kind of stone which is a species of amianthus, consisting of flexible fibres loosely interwoven, and somewhat resembling vegetable cork. It is the lightest of all stones; by fire it is infusible. It possesses the general qualities of amianthus. See Mountain Cork, MINERALOGY Index.