Of the three divisions of the vegetable kingdom, the exogenæ alone furnish building timber, properly so called, and it is doubtful whether nature has supplied a more generally applicable substance than wood; being a bad conductor, it can be handled in the coldest weather, which metal cannot, and, being easily cut or split, can be fashioned into almost any form. [Illustration: FIG. 21--EXOGENOUS LEAF, SHOWING RETICULATED VENATION.] The woods mostly in use for general purposes are the different kinds of pine, as American Pine, Norway Pine, yellow and white Deal, Mahogany, Oak, Beech, Elm, Ash, and Maple. In the "Penny Cyclopædia," under the article "Wood," is the following description of the different kinds used by cabinet-makers, &c.:-- "The woods that are used by the cabinet-maker for furniture of a more delicate kind are called 'fancy woods.' The use of these has become much more general since the introduction of the art of veneering, and now that this is done by machinery instead of by hand, a number of woods are used for furniture and other purposes, which, on account of their scarcity, could have been formerly used only to a very limited extent. The most common of the fancy woods, and that which is most used by cabinet-makers, is Mahogany. This wood is the produce of the 'Swienteria Mahogani.' "Next in point of importance and use to Mahogany, is Rosewood. This wood obtains its name from its fragrance, and is the produce of a mimosa from the forests of Brazil; in veneering it affords about eight plates to the inch. "King-wood is a beautiful wood much in use, brought from Brazil in logs four feet long and about five inches wide, and is used only for delicate articles; it is said to be the produce of a species of Baphia, a genus of Leguminous plants. "Beef-wood is a very heavy wood of a pale red colour, and is brought from New Holland in logs nine feet long and thirteen or fourteen inches wide; the tree from which this is obtained is unknown to botanists, as well as most of those producing the fancy woods of commerce. "Tulip-wood is brought into the market in very small pieces, not more than four feet long and five inches in diameter, so that probably it is the production of a shrub; it is clouded with red and yellow colours, and is used for bordering and for making small articles, such as caddies and work-boxes. "Zebra-wood is probably the production of a large tree, as it is cheap enough to be made into tables, pianofortes, &c.; it is coloured brown on a white ground and clouded with black. "Satin-wood is of a brilliant yellow colour with delicate glowing shades. It is the produce of a plant called Chloroxylon Swienteria, a native of India; it is one of the trees that yield the wood-oil of India, and belongs to the natural order Cedrelaceæ, the same order in which the mahogany is placed; it is found in the market in logs two feet wide and seven or eight feet long.