bark properties bottles outer CORK (perhaps from cortex, bark)
is the outer layer of the bark of an evergreen species of oak
(Querces Suter). The tree reaches the height of about 30 feet,
growing in the south of Europe and on the North African coasts
generally ; but it is principally cultivated in Spain and
Portugal. The outer layer of bark in the cork oak by annual
additions from within gradually becomes a thick soft homogeneous
mass, possessing those compressible and elastic properties upon
which the economic value of the material chiefly depends. The
first stripping of cork from young trees takes place when they
are from fifteen to twenty years of age. The yield, which is
rough, unequal, and woody in texture is called virgin cork, and
is useful only as a tanning substance, or for forming rustic
work in ferneries, conservatories, &c. Subsequently the bark is
removed every eight or ten years, the quality of the cork
improving with each successive stripping ; and the 'trees
continue to live and thrive under t