1696

ARBORETUM AND FRUTICETUM.

PART III.

of them. Artificially, the birch recommends itself to the proprietor of woods andto planters, by the following qualities:—1st, By the lightness and multiplicityof its seeds, which it begins to produce at the age of six years; and which,being spread abroad on every side by the wind, give rise to a great number ofyoung plants; thus producing a thick wood, without either care or labour.2dly, By the rapidity of its growth, and the resistance which it makes to allthe circumstances which usually destroy trees, and eradicate woods. 3dly,By its power of withstanding a great degree of both heat and cold. 4thly, Byits suffering little from the bite of cattle, and being but seldom attacked bycaterpillars, which are said only to have recourse to it after they have de-stroyed all the succulent leaves in the same forest; and which, consequently,being then nearly matured, can do it but little harm. 5thly, By its notrequiring the shade or protection of other trees; while its own shade, fromthe lightness and thinness of its foliage, is extremely favourable to the growthof oaks, beeches, and, above all, the pine and fir tribe, which spring up underits protection with great vigour. Hence, the value of the birch as a nurse tohard-wooded trees, which it protects in their youth, but which destroy itwhen they acquire strength. 6thly, By its not injuring other trees with itsroots, which run along the surface of the soil, and draw but very little nourish-ment from it. 7thly, By its succeeding almost every where, and improvingpoor soils by the deposition of its leaves. 8thly, By its furnishing usefulproducts, such as spray for brooms, &c., a very short time after being planted.And, 9thly, by its producing a wood almost exclusively employed in Sweden,and other parts of the Continent, for smelting-furnaces ; and in other caseswhere a bright clear flame is required. Though all these advantages, says theauthor of the article Bouleau, in the Dictionnaire des Faux et Forcls , belong tothe birch, we cannot place it in the first rank of forest trees; and the oak,the beech, and other trees of stately growth, are to be preferred to it in goodsoils : but the birch cannot be too strongly recommended for light and poorsoils, sands, and chalks. In Prussia, he adds, the birch is planted everywhere; and it is considered to afford security against a dearth of fuel, and to in-sure the prosperity of the woods, by the dissemination of its seeds, which fillup every blank that occurs.

The wood of the birch is white, shaded with red ; of a medium durabilityin temperate climates, but lasting a long time when it is grown in the extremenorth. The grain of the wood is intermediate between coarse and fine. It iseasily worked while it is green ; but it chips under the tool when dry. Itweighs, when green, 05 lb. 6 oz.; half-dry, 50 lb. 6 oz. ; and dry, 45 lb. 1 oz.The wood of old birch trees is harder than that of young trees, and it alsoweighs considerably more : for it appears, by the experiments of Hartig, thatthe wood of a tree of 00 years’ growth, weighed, dry, 30 lb. 13 oz.; whilethat of a tree of 25 years’ growth, in the same state of dryness, onlyweighed 351b. 5oz. The wood soon rots when laid on the ground in heaps;and, therefore, immediately after the trees are felled, they ought to be drawnout of the wood, and taken into the timber-yard, where they can be exposedfreely to the air. As fuel, birch wood occupies the 12th place among 21different sorts; and is to the fuel of the beech as 13 is to 15 : but, if thewood of the birch is to be compared with that of the beech, taken in thebulk, it is only as 12 to 15 ; because birch logs, not being so straight as thoseof the beech, do not pack so closely together. The wood gives a clear, bright,and ardent flame, and affords the kind of fuel most generally used in Sweden,Russia, and France, for smelting-furnaces. Its charcoal remains burning along time ; though, compared with that of the beech, its value is only as 14Jto 16. The bark of the birch is remarkable for its durability, remaining un-corrupted for ages, even in situations exposed alternately to air and water, coldand moisture. Pallas refers, in proof of this, to the tombs near Jenisca, inSiberia; and to the vaults under the Kremlin, in Moscow. When Mauper-tuis travelled through Lapland, “ to measure a degree of latitude, he wasobliged to pass through vast forests, consisting entirely of birch. The soil, insome parts of these wastes, being very shallow, or very loose, the trees had