Hazelnut Tree, or Co-rylus, L. a genus of plants consisting of four species : one of these is a native of Britain, namely, the avellana, or Common Hazel-nut tree. It grows in woods, copses, and hedges; flowers in March or April.

All the diferent species of the hazel are large, hardy, and deciduous shrubs; they have several varieties, valuable for their fruit, which, in a cultivated state, is known under the name of Fil-berls.

These shrubs prosper in almost any soil, or situation ; and may be propagated either by layers, or by planting their nuts in February; for which purpose the latter should be preserved in sand, in a moist cellar, inaccessible to vermin ; but they should not be secluded from the external air, for want of which they will become mouldy. When reared in coppices, this shrub produces abundance of underwood, that may be cut every 5th, 7 th, or 8th year, according to the purpose for which it is designed.

The uses of this wood are various : it is employed for poles, hoops for barrels, spars, hurdles, handles for implements of husbandry, walking-sticks, fishing-rods, etc. Where beautiful specimens are required for veneering or staining, the roots of the hazel-nut tree are preferable to the branches. In Italy, the chips are used for fining turbid wines ; and in countries where yeast is scarce, the twigs of this shrub, dried, and afterwards soaked in the fermenting liquor, serve as a substitute for that article in brewing. Painters and engravers prepare coals for drawing outlines, from the wood of this plant, by the following process : Pieces of dried hazel, about the thickness of a fin-ger, and 4 or 5 inches in length, are put into a large pot filled with sand, and the top of which is closely covered with clay. In this manner they are placed in a potter's oven, or otherwise exposed to a sufficient degree of heat; and, on cooling, the sticks are found to be converted into charcoal, which draws freely, and is easily effaced with India-rubber.

According to EVELYN, no plant is better calculated for thickening copses than the haze!; with this view he recommends the following expeditious method: Take a pole of hazle (for which ash or poplar may be substituted) of 20 or 30 feet in length, the head of which is -somewhat lopped into the ground ; the pole should likewise be chopped near the soil, in order to make it yield : thus fastened to the earth with a hook or two, and covered with fresh mould sufficiently deep, it will produce an incalculable!) um ber of suckers, speedily thicken, and tarnish a fine coppice.

The kernels of the fruit of the hazel-nut tree, though difficult of digestion, have a mild, farinaceous, oily taste, which is agreeable to most palates ; yet filberts are said to be more nourishing than nuts : both, however, operate as a cathartic, when chewed small and taken in considerable quantities ; but produce constipations of the bowel-, if swallowed in large pieces ; and dysentery, if eaten unripe. A kind of chocolate has been prepared from this fruit, which has also occasionally been converted into bread. An expressed oil is obtain-t:d from the nuts, which is little inferior to that of almonds: it is often preferably used by painters, as it readily dries; and chemists employ it as the basis of fragrant oils artificially prepared, because it •easily combines with, and retains, odours. An emulsion made of the kernels, and taken with good old mead, is recommended for inveterate dry coughs. - Squirrels and mice are excessively fond of the nuts; goats and horses eat the leaves, but they are refused by sheep and hogs.