This order contains some of our finest trees; the Oak, that prince of trees, is of this order. It attains a great age and size, and there are some celebrated specimens existing which have stood many centuries. Oaks constitute 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 purpose, 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 annually. Moreover, the Gall-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. [Illustration: Sweet Chestnut.] 7. EUPHORBIACEÆ (Buxus sempervirens) Box. [Illustration: Box.] Many species of this order are acrid and poisonous, and have been used for poisoning arrows. The Castor-oil plant (Ricinus 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-wood, is obtained. 8. URTICACEÆ (Urtica urens) Stinging Nettle. (Humulus lupulus) Hops. [Illustration: Hop.] The Nettle in Australia grows to the size of a tree; the Hop also belongs to this order, and is largely cultivated in Kent and Sussex for the use of brewers, as it communicates an agreeable bitter to beer which no other plant seems to be able to substitute. 9. SALICACEÆ (Salix alba) White Willow. (Populus nigra) Black Poplar. [Illustration: White Willow.] The most characteristic of this order are the examples given; the Willows are well-known trees, growing by the margins of water and in damp places. The Poplar is one of our tallest trees, specimens being known 100 feet high; its peculiar tall form distinguishes it from all other trees. 10. BETULACEÆ (Betula alba) Birch. (Alnus glutinosa) Alder. [Illustration: Birch.] [Illustration: Alder.] The Birch and Alder are both well known trees in our plantations, the Alder is often confounded with the Elder. The bark of the Birch tree contains tannin; it is used to tan skins in Russia, and gives to Russian leather its peculiar qualities. 11. ULMACEÆ (Ulnus campestris) Elm. [Illustration: Elm.] The Elm is one of our largest and noblest trees, growing to 80 or 90 feet high, it has often a girth of 10 to 11 feet, and forms a very fine tree with a broad crown; the wood is much used for making coffins.