294 POPULAR ECONOMIC BOTANY. 



Cork (called commercially Corkwood). — The outer bark 

 of the Cork Oak (Quercus Suber, Nat. Ord. Corylacece) . 



This very useful substance is formed by the tree between 

 the outermost and innermost layers of its bark ; it consists of 

 a peculiar cellular mass, the individual cells of which are 

 distended with a curious grumous secretion, which hardens 

 and dries, and forms the substance of the Cork. When the 

 Cork Oak is nine or ten years old, the outer bark splits and 

 the second layer grows, and increases very much in bulk 

 by the constant secretion of the corky matter : this would 

 fall off naturally in nine or ten years, but is usually removed 

 when six or seven years old. The removal is effected by 

 cutting a slit through the bark from the top of the trunk 

 to the bottom, and a transverse one at each end; the cork 

 will then easily peel off; it is afterwards removed, in large 

 curled- up pieces, to properly prepared pits ; here the sheets 

 are piled up one upon another, and heavy weights are placed 

 to flatten them down ; water is then let into the pit, and 

 the cork left to soak for a time, it is then taken out and 

 dried, and retains its flatness. Its use in making corks 

 for bottles is very generally known ; it is also used for a 

 variety of economic purposes, amongst which cork soles for 

 shoes, making life-buoys, etc. The imports amount to 2520 

 tons, an enormous quantity of so light a material. 





