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POPULAE ECONOMIC BOTANY. 



CoEK (called commercially Corkwood). — The outer bark 

 of the Cork Oak [Querctis Suber, Nat. Ord. Corylacecd). 



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 grnmous 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. 



