2174

ARBORETUM AND FRUTICETUM.

PART III.

mities of the trunks are found extremely useful after snow has fallen, andbefore it has become hard with the frost, and also on the commencement ofa thaw, in indicating to the traveller when his horses are getting too nearthe edge of the road. Roads of this rude description are peculiarly suitablefor marshy ground, and are very common in the interior of Russia , and alsoin some parts of Poland . Recourse is also had to them in the commence-ment of back settlements in North America . In 1814, the greater part ofthe road from Petersburg to Moscow was of this kind; but it has since, weunderstand, been Macadamised. The practice of paving streets and court-yards with blocks, cut from the trunks of Scotch pines, and set up endwise,has been already mentioned, p. 2133.

Mode of procuring the resinous Products of the Scotch Pine in the North ofEurope . The turpentine obtained from the Scotch pine is so inferior to thatof the silver fir, that very little is made use of in the way of commerce,except for the coarsest kinds of work. To procure it, a narrow piece of barkis stripped off the trunk of the tree in spring, when the sap is in motion, anda notch is cut in the tree, at the bottom of the channel formed by removingthe bark, to receive the resinous juice, which will run freely down to it. Asit runs down it leaves a white matter like cream, but a little thicker, which isvery different from all the kinds of resin and turpentine in use, and which isgenerally sold to be used in the making of flambeaux, instead of white beeswax. The matter that is received in the hole at the bottom is taken up withladles, and put into a large basket; a great part of this immediately runsthrough, and this is the common turpentine. It is received into stone orearthen pots, and is then ready for sale. The thicker matter, which remainsin the basket, is put into a common alembic; and a large quantity of waterbeing added, the liquor is distilled as long as any oil is seen swimming uponthe water. The oil which is produced in large quantities is then separatedfrom the water, and is the common oil or spirit of turpentine; and theremaining matter, at the bottom of the still, is the common yellow rosin.

Tar is procured from the Scotch pine in great quantities in the north olEurope, and is considered very superior to that produced in the UnitedStates from P. resinosa, .Vtrobus, australis, and other species. The processfollowed in Sweden , by which both tar and charcoal are obtained, thoughthe latter is there of little value, is thus described by Dr. Clarke:—“T” einlets of the gulf (Bothnia) every where appeared of the grandest charac-ter ; surrounded by nobie forests, whose tall trees, flourishing luxurianty>covered the soil quite down to the water’s edge. From the most southernparts of Westro-Bothnia, to the northern extremity of the gulf, the inhabi-tants are occupied in the manufacture of tar; proofs of which are visible inthe whole extent of the coast. The process by which the tar is obtaineis very simple; and, as we often witnessed it, we shall now describe it, froffl •tar-work we halted to inspect upon the spot. The situation most favourab eto the process is in a forest near to a marsh or bog; because the roots of tnScotch pine, from which tar is principally extracted, are always most pro-ductive in such places. A conical cavity is then made in the ground (gene-rally in the side of a bank or sloping hill); and the roots together with logand billets of the wood, being neatly trussed in a stack of the same corucshape, are let into this cavity. The whole is then covered with tun.prevent the volatile parts from being dissipated, which, by means of a " ea ?wooden mallet, and a wooden stamper worked separately by two t ne ®> .beaten down, and rendered as firm as possible above the wood. Thesta^of billets is then kindled, and a slow combustion of the pine takes place, 3 smaking charcoal. During this combustion the tar exudes; and, a cast-iron pbeing fixed at the bottom of the funnel, with a spout which projects tnio“j?jthe side of the bank, barrels are placed beneath this spout to collect theas it comes away. As fast as these barrels are filled, they are bunged)are then ready for immediate exportation. From this description, it w>evident that the mode of obtaining tar is by a kind of distillation per u es