Book III. USES OF TREES AND PLANTATIONS. 937 



pseudacaria). Charcoal, as fuel, is prepared by subjecting roots, or the more ligneous 

 parts of branches, to a smothering combustion. 



6754. For affording the tannin principle, the bark of the oak Is chiefly used ; but that of the Hunting- 

 don willow (Salix alba), larch, black poplar, birch, chestnut, hazel, thorn, and some other trees, is found 

 to afford it in such quantities as renders it worth while to disbark them for that purpose. (Agr. Chem. 89. 

 and Com. to Board of Agr.) The bark is most powerful when taken from the tree at an early age, and 

 hence the oak is cut down before it attains a timber size, for that purpose, as in copse-woods ; but the bark 

 of old trees is also used. 



6755. For dyeing, the bark of several trees was formerly in use, as of the crab-apple, pear, ash, alder, &c. 

 The bark of the quercitron (Quercustinctoria) is used for dyeing yellow in North America ; but in this 

 country, foreign materials, as indigo, logwood, madder, &c. have superseded the use of indigenous, or home- 

 grown vegetables. The berries of some trees, as of the elder, and berry-bearing alder ; and the leaves of 

 others, as of the walnut and sloe, have also been used as dye-stuffs. 



6756. In various arts and manufactures some of the products of trees are used, as the charcoal (of the 

 dogwood principally) in that of gunpowder ; the pitch of the pine, the resin of the spruce fir, and the tur- 

 pentine of the larch, for a great variety of purposes. The ashes of the burnt branches of all trees, but 

 especially of the ash, afford alkali for the laundress ; the spray of the beech and other trees affords, on 

 distillation, the pyroligneous acid, an excellent preservative of timber, and, when purified, a substitute 

 for salt in preserving butcher-meat ; the bark of the holly affords birdlime ; and the leaves of all trees, 

 excepting the resinous kinds, rot into excellent manure for the field, and highly prized vegetable mould 

 for the garden. 



6757. For food to man, in his present state, the timber-trees afford but little resource ; but nuts of the 

 sweet chestnut, walnut, and hazel are still esteemed, and our ancestors used the acorn, beech-mast, haw, 

 roan, hip, and bramble. A very agreeable drink is made from the sap of the birch-tree in Sweden, Russia, 

 and some parts of Britain ; and, in America, sugar is obtained from the sugar-maple (Acer saccharinmn) 

 in sufficient quantities to be used in domestic economy. Mast and acorns are esteemed excellent food for 

 swine, haws for deer, and the leaves and spray of many sorts of trees are, or may be, eaten during winter 

 both by domestic and wild animals. Game, which, in every cultivated country, is one of the greatest 

 luxuries of the table, is localised by plantations, in which both birds and quadrupeds find at once shelter, 

 security from their enemies, and food. 



6758. For medicine, the products of scarcely any British tree is in use ; but the bark, blossoms, and 

 berries of the elder ; the fruit of the sloe and crab, and the leaves of the walnut were formerly in consi- 

 derable repute, and are occasionally used. 



6759. As poisons for vermin, the leaves of the walnut, elder, and ash are used by infusion for destroy- 

 ing, or rather annoying, worms by their bitter acrid quality ; a glutinous snare lor entrapping birds is 

 obtained from the holly and mistletoe. 



6760. General remit. From the above outline it may be inferred, that the timber-trees in most general 

 demand as such, are the oak, pine, and fir tribes ; and next the ash, elm, beech, poplar, willow, birch, 

 sycamore, &c. In the greater number of cases, ceteris paribus, the oak, larch, Scotch pine, ash, abele, 

 poplar, and willow, will be found the most profitable trees that can be planted with a view to timber or 

 bark produce. 



Sect. II. Of the Uses of Trees collectively as Plantations. 



6761. Trees collectively in a growing state may be useful by affording shelter and im- 

 proving the local climate, improving bad soils, producing shade, by separation, seclusion, 

 distinction, appropriation, concealment of disagreeable objects, heightening the effect of 

 agreeable objects, creating beauty, and adding value prospectively. 



6762. Shelter and climate. The umbrageous roof of the forest afforded shelter, and 

 a secure retreat to our savage forefathers ; and their civilised descendants still resort to 

 the nearest tree as a place of shelter during a casual storm ; to the thick forest as a place 

 of security, when they set the laws of their country at defiance, or have committed crime. 

 Considered agriculturally, " the advantages to be derived from subdividing extensive 

 tracts of barren country by plantations, are evidently great, whether considered in the 

 light of affording immediate shelter to the lands, or in that of improving the local climate. 

 The fact that the climate may be thus improved, has, in very many instances, been suffi- 

 ciently established. It is, indeed, astonishing how much better cattle thrive in fields 

 even but moderately sheltered than they do in an open exposed country. In the breed- 

 ing of cattle, a sheltered farm, or a sheltered corner in a farm, is a thing much prized ; 

 and, in instances where fields are taken by the season for the purpose of fattening them, 

 those most sheltered never fail to bring the highest rents, provided the soil be equal with 

 that of the neighboring fields which are not sheltered by trees. If we enquire into the 

 cause, we shall find that it does not altogether depend on an early rise of grass, on 

 account of the shelter afforded to the lands by the plantations ; but, likewise, that cattle 

 which have it in their power, in cold seasons, to indulge in the kindly shelter afforded 

 them by the trees, feed better ; because their bodies are not pierced by the keen winds of 

 spring and autumn ; neither is the tender grass destroyed by the frosty blasts of March 

 and April." (Plant. Kal. p. 121.) In gardening, as we have already seen (2400.), 

 shelter is not less important than in general economy. 



6763. Climate. An Italian author (G. Gautieri) has enumerated and illustrated the advantages, in point 

 of climate, which entire tracts of country derive from extensive woods and forests. " These," he says, 

 " are the arresting the progress of impetuous and dangerous winds ; maintaining the temperature of the 

 air ; regulating the seasons ; lessening intense cold ; opposing the formation and increase of ice ; moder- 

 ating intense heats ; producing abundance of rain and snow ; giving origin to springs, and producing 

 abundance of water in the rivers ; discharging the electricity of the atmosphere; dispersing hail, snow, 

 and watery clouds ; preserving from inundations ; lessening the width and depth of torrents ; opposing a 

 barrier to the undermining of banks, and the formation of precipices ; preserving the soil on mountains, 

 by which their external figure is maintained ; and, finally, retaining within bounds, or disturbing the 

 formation of avalanches, or accumulations of snow." He illustrates each of these propositions by refer- 

 ences to what has taken place in Italy and Germany, in consequence of alterations that have been made 

 in the woody surfaces of these countries. (De/lo Influsso de' Bosch/, Sec. Milano, 1817.) Williams, an 

 English author (1292.), has endeavored to show that the climate of Britain is deteriorating by the increase 



