203 THE VEGETABLE KINGDOM. 



existing which have stood many centuries. Oaks con- 

 stitute the greater part of the forest trees, both on the 

 Continent and in England; great 

 numbers are cut in France 

 for fire-wood, and in both 

 countries for ship-building. The 

 roof-timbers of our old churches 

 and halls are nearly all oak. The 

 bark of the oak is largely used 

 for tanning leather. About 

 30,000 tons are imported into 

 this country yearly for this pur- 

 pose, besides the product of our 

 own trees. The bark of the 

 Cork-oak (Quercus suber) is 

 used for making corks, some 

 2,000 tons of this are imported 



aweec onestnut. ,, -,.- j-i -i n 



annually. Moreover, the Grail- 

 nut used in tanning, and also to make black dye, is the 

 product of an oak. The Chestnut is a fine tree, the 

 nuts of which are commonly eaten by the peasantry of 

 Spain and Italy as food ; the tree grows to a great 

 age and to an enormous size. 



7. EUPHORBIACEJE (Buxus sempervirens) Box. 



Many species of this order are 

 acrid and poisonous, and have 

 been used for poisoning arrows. 

 The Castor-oil plant (Bid mis 

 palma-christi), and the plant 

 that yields that most violent 

 purgative, Croton-oil (Croton 

 tiglium), are of this species ; 

 also the Box-tree, from which 

 that useful wood, known as 

 Box. box-wood, is obtained. 



