BAR 



thcfe fibres, are deftroyed by putrcfaftion ; and after- 

 wards by drying them, and beating off with hammers what 

 may Hill adhere. 



Thefe fibrous parts of the barks of trees, as they contain 

 no faccharine matter, like the alburnum, are, he obferves, 

 much lefs liable to decay than the fap-wood, or perhaps than 

 any part of the timber. Maupertuis, he adds, who went to 

 Lapland to nieafure a degree of the meridian, lays, that 

 among the numerous trees which lay upon the ground, de- 

 ftroyed by age, or blown down by the winds, many birch 

 trees appeared whole, owing to the undecayed ftate of their 

 bark, but crumbled into powder on being trod upon ; and 

 that the Swedes took the pradice from this of covering their 

 houfes with this unpcrilhable bark, on which they fometiuies 

 lay foil, and thus poffefo aerial gardens. 



To increafe the quantity of bark, it mu!l, the doftor re- 

 marks, be remembered, that the leaf-buds, or viviparous otl- 

 fpring of trees, as they form new buds, acquire new cau- 

 dexes extending down into the ground, and thus increafe the 

 bark of the ftem in thickncfs; but the flower-buds acquire 

 no new caudexes, but die as foon as they have ripened their 

 feed, and confequently do not increafe the thxkiiefs of the 

 bark. Whence one method of increafing the quantity of the 

 bark is to increafe the number or vigour of the leaf-buds, in 

 contradidlion to the flower-buds, which may be done by 

 pinching off the flowers as foon as they appear; and as the 

 bark becomes gradually changed into wood, this may be 

 one metlKid, alfo, he thinks, of forwarding the growth of 

 timber-trees. 



It is added, that the method of preferving the bark of 

 trees from mofs conlifls in rubbing off that parafite vegetable 

 in wet weather, by means of a hardiffi brufli; which is faid 

 to be ufed with advantage on the apple-trees in the cyder 

 countries; and may, at the fame time, give motion to the 

 vegetable circulation, or forward the afcent of their juices 

 abforbed by the radical or cortical abforbents. In dry wea- 

 ther, the brufli fliould be frequently dipped in water. Wafh- 

 ing the barks of wall-trees by a water-engine, may alfo faci- 

 litate the protrufion of their buds in dry leafons; and might 

 poffibly prevent the canker, if applied to dwarfs or efpaher 

 apple-trees. Other parafite vegetables mull be occafionally 

 deftroyed where they occur; as the lichens, fungi, mifletoe, 

 with the ivies and other climbers, as fome kinds of lonicern, 

 clematis, and fiimjria, woodbine, virgins-bower, and fumi- 

 tory. 



It is further remarked, that when a wound is made in 

 the bark of a tree, fo as to expofe the alburnum to the 

 air, the upper hp of the wound is liable to grow faller 

 downwards than the lower one is to grow upwards, owing 

 to the former being fnpplied direftly with nutritive juiees 

 fecreted from the vegetable blood after its ventilation, and 

 confequent oxygenation in the leaves; whereas, the lower hp 

 only receives thofe juices laterally by the inofcnlalion of 

 veffels. Over thefe wounds the cuticle is liable to project, 

 and to fupply a convenient hiding-place for infe£ls, which 

 cither eat the new fibres of the growing bark, and perforate 

 the alburnum; or by their moiiluie, their warmth, and their 

 excrements, contribute to the decay of tlie albnraum, and 

 prevent the healing of the wound. Thefe dead edges of the 

 proiecling bark or cuticle fliould therefore, it is faid, be 

 aicelv cut off, but not io as to wound the living bark. 



It is remarked, that plan;ers of lime or of tar with fi:b- 

 limate of mercury, have been recommended to prefei-ve the 

 wounded parts from the air, and from moillure, and from 

 infefts; but as all thefe materials are injurious to the libies 

 cf the living bark, they fkould be ufed with caution, fo as 



BAR 



not to touch the edges of the wound, but only to cover the 

 alburnum ; for this purpofe, white lead and boiled oil, mixed ■ 

 into a thick paint, or with the addition of fublimate of mer- 

 cury, or of arfenic, or of fpirit of turpentine, may probably 

 anfvver the purpofe ; and may be of real utility on the wounds 

 of thofe trees whofe wood contains lefs acrimony, and is 

 therefore more liable to be bored into and eaten by a large 

 worm or maggot, .ilmoft as thick as a goofe-quill; which 

 the dodtor has fcen happen to a pear-tree, fo as to con- 

 fume the whole internal wood, till the tree was blown 

 down. 



In refpeft to the caution neceffary to be obferved in not 

 touching the living edges of the wounded bark with fuch 

 materials as may injure the tree by their abforption, he re- 

 members feeing fevcral young elm-trees which died by their 

 hules having been covered, as he was informed, by quick- 

 lime, mixed with cow-dung, to prevent their being injured 

 by horft-s ; and he has fcen branches of peach and nectarine 

 t res deftroyed by fprinkling them, when in leaf, with a 

 light folution of arfenic, and others with fpirit of turpentine. 

 The compofilion recommended by ]\Ir. Foifyth, in his 

 " Treatife on the Culture and Management of Fruit Trees," 

 which is conftituted of cow- dung, eftete lime, wood-a(hes, 

 and river fand, feems however to have been made uie of in 

 thofe cafes with much advantage, and without any incon- 

 venience having been experienced in this way. 



It is further rtated, by the author of Phytologia, that a 

 more curious method of cure is faid to have fucceeded, 

 where the bark of a tree has recently been torn off, even to 

 great extent ; and this is, by binding the fame piece of bark 

 on again, or another piece from the fame tree, or from one 

 of a finiilar nature, nicely adapting the edges of the bark 

 to be applied to the edges of that which fuirounds the 

 wound of the tree, which, it is faid, will coalefce, in the 

 fame manner as the veffels of the bark of an ingrafted fcion, 

 unite with thofe of the bark of the flock ingrafted on ; 

 which is ilriftly analogous to the union of inflamed or 

 wounded parts of animal bodies, as in the cure of the hare- 

 lip, or the infertion of the living tooth from one perfon into 

 the jaw of another. 



If the bark, over the cankered parts of apple-trees, adds 

 the doftor, could be thus renewed by paring the edges of 

 the m.ortified bark to the quick, and then nicely applying a 

 piece of healthy bark, from an apple-tree of inferior value, 

 and fccuring it with an elaftic bandage, as a ftircd of flan- 

 nel, it would be a very valuable dilcovery. Another method, 

 where a branch of a valuable tree is in the progrefs of being 

 deftroyed by canker, might, he obferves, be by inclofing the 

 cankered part, and fome inches above it, in a garden pot 

 of earth previoufly divided, and fupported by ilakes, and 

 tied together round the branch ; which might then ftrike 

 roots in the earth of the garden-pot, and, after fome months, 

 be cut off, and planted on the ground, and miglit thus be 

 preferved, and produce a new tree ; which experiment (the 

 doelor fays) he has tried on two apple-trees, and believes 

 it will fucceed. 



Bark, in its dead ftate, after having been employed 

 in the vat of the tanner, is found to be a material of 

 great utility for the purpole of conllituting thofe hot- 

 beds in ftoves and pits conftruAed for them, that are 

 uRudly denominated bark-heds, and which from their 

 being much more regular and durable in the temperature 

 of their heat, than thoie formed from dung, become a great 

 deal more convenient and ufeful for different pnrpofes of the 

 gardener ; and are of courfe employed witii much advan- 

 tage in the growth and culture of various tender and curious 



exotic 



