the BIRCH-TREE; a genus of the te-trandria order, belonging to the monocotyledon class of plants.

Species. 1. The alba, or common birch-tree, is so well known as to need no description. 2. The nana, or dwarf-birch, with roundish leaves, grows naturally in the northern parts of Europe, and on the Alps. It seldom rises above two or three feet high, having slender branches garnished with round leaves, but seldom produces flowers here. It is preserved in some curious gardens for the sake of variety, but is a plant of no use. 3. The lenta, with oblong, pointed, heart-shaped, sawed leaves. 4. The nigra, or black Virginia birch-tree. Both these are natives of North America. In Canada they grow to a large size, and the third sort is there called meriflora. 5. The alnus, or alder-tree. Of this there are two varieties, one with round leaves, and the other with long ones.

Culture. The first sort is not much esteemed for its wood; but, however, may be cultivated to advantage upon barren land where better trees will not thrive; for there is no soil so bad but this tree will thrive in it. It will grow in moist springy land, or in dry gravel or sand where there is little surface; so that upon ground which produced nothing but moss, these trees have been known to succeed so well as to be fit for cutting in ten years after they were planted. The best method of raising these trees is, to procure the young plants from the woods where they naturally grow, and where they are usually found in great plenty; but in places where these young plants cannot be procured, they may be raised from seeds, which should be carefully gathered in the autumn as soon as the scales under which they are lodged begin to open, otherwise they will soon fall out and be lost. The seeds are small, so should not be buried deep in the ground. The best time for sowing them is in the autumn in dry ground, and the spring in moist. The plants will thrive better in a shady situation than if exposed to the sun. If the wild plants are used, they ought to be taken up carefully, so as not to injure their roots. The ground where they are to be planted requires no preparation; all that is necessary to be done is to loosen the soil with a spade or mattock in the places where the plants are to stand, making holes to receive their roots, covering them again when the plants are placed, and closing the earth hard to their roots. If the plants are young, and have not much top, they will require no pruning; but where they have bushy heads, they should be shortened to prevent their being shaken and displaced by the wind. When the plants have taken root, they will require no other care but to cut down the great weeds which would overhang them. This need not be repeated oftener than twice in a summer the first two years; after which the plants will be strong enough to keep down the weeds, or at least be out of danger from them. These trees may be planted any time from the middle of October to the middle of March when the ground is not frozen. They ought to be planted four feet distance from each other, that they may soon cover the ground, and by standing close they will draw one another up. If the plants take kindly to the ground, they will be fit to cut in about ten years; and afterwards they may be cut every seventh or eighth year if designed for the broom-makers only; but if designed for hoops, they should not be cut oftener than every twelfth year. The nana, lenta, and nigra, are to be propagated in the same manner; but the alder may be propagated either by layers, or planting truncheons about three feet high. The best time for this is in February, or the beginning of March. They should be sharpened at one end, and thrust at least two feet deep in the ground, to prevent their being blown out of it after they have made strong shoots. The best time for laying down the branches is in the month of October, and they may be transplanted in October following.

Uses. In some of the northern parts of Europe the wood of the birch is much used for making carriages and wheels, being hard and of long duration. In France it is generally used for making wooden shoes, and in Britain for making women's shoe-heels, packing-boxes, brooms, hoops, &c. It also makes very good fuel, and is planted along with hazel to make charcoal for forges. The bark of the birch tree seems in a manner incorruptible. In Sweden the houles are covered with it, and it lasts many years. It frequently happens that the wood is entirely rotten, when the bark is perfectly sound and good. In Kamtchatka it is used for making drinking cups. It abounds with a resinous matter, to which its durability is certainly owing. In consequence of this matter, it is highly inflammable; and in the northern countries torches are made of this bark. bark sliced and twisted together. The bark itself consists of two different substances; a thick brittle brownish red one; and several very thin, smooth, white, transparent membranes. In these last the inflammable property resides. The thick brittle part is less resinous, and has a roughish taste. It has been thought to possess some medical virtues, but concerning these experience has as yet determined nothing certain. Upon deeply wounding or boring the trunk of the tree in the beginning of spring, a sweetish juice flows forth, sometimes, as is said, in large quantity as to equal the weight of the whole tree and root; one branch will bleed a gallon or more in a day. This juice is recommended in scorbutic disorders, and other foulnesses of the blood; its most sensible effect is to promote the urinary discharge. By proper fermentation with the addition of sugar, this juice makes a pleasant wine. The birch-tree is said to be prejudicial to pasturage.

The alder tree flourishes best in low marshy situations, in which it is frequently planted to make hedges, and is also of great use for securing the banks of rivers. Gras grows well beneath its shade: the wood is soft and brittle; but lasts a long time under water, and consequently is of use for pipes, and to lay under the foundations of buildings situated upon bogs: women's shoe-heels, ploughman's clogs, and various articles of the turner kind, are made of it. The bark gives a red colour, and with the addition of copperas a black: it is chiefly used by fishermen to stain their nets. In the Highlands of Scotland near Dundonnel, Mr Pennant says the boughs cut in the summer, spread over the fields, and left to rot in the winter, are found to answer as a manure. In March, the ground is cleared of the undecayed parts, and then ploughed. The fresh gathered leaves are covered with a glutinous liquor; and some people threw them on their floors to kill fleas. These insects are said to be entangled in the glutinous liquor of the leaves, as birds are by birdlime. The whole plant is astringent, and its bark has been recommended in intermittent fevers. Horses, cows, goats, and sheep, eat all the species of betula; but swine refuse them.