30 A MAN0AL OF THE CONIFERS. 



repay the cost of collecting for exportation, in consequence of the 

 cheaper rate at which it is procured further south. The Coniferse of 

 the Himalayas yield but a small amount of resinous products owing to 

 the humidity 'of the climate;* and in Britain — although the more equable 

 temperature of summer and winter, especially in the districts of the 

 greatest rainfall, is favourable to the rapid growth of the trees — the 

 resinous products are not sufficiently abundant to be worth collecting. 



The Turpentine imported into Great Britain exceeds half a million, 

 of cwts. annually. The Tar received from the north of Europe, 

 obtained from Pinus sylvestris, and used chiefly in shipbuilding (of which 

 the Stockholm Tar of commerce is considered the best), and that from 

 North America, obtained from Pinus australis, P. Twda, P. rigida, &c, 

 exceeds yearly five millions of gallons. The distillation of tar, both 

 in Europe and America, is usually performed in a very rude manner, 

 involving an enormous waste of material. " A funnel-shaped hole is 

 dug in a bank, about six or eight feet in diameter at the upper part 

 and not more than ten inches at the lower. At the bottom of the 

 hole is placed an iron pan having a long pipe or spout which is made 

 to pass through the bank ; the hole is then filled up with billets cut 

 from the roots and branches of the Pine Trees, which, after bein» 

 kindled at the top, are covered over incompletely with turf. The wood 

 is then charred from above downwards, and the tar, mixed with 

 various other products, flows off at the bottom through the spout into 

 a receiver.'' t 



DISEASES AND ACCIDENTS. 



Coniferous plants are liable to disease which manifests itself in 

 various forms, the most common as well as the most virulent being 

 fungoid. One kind of fungoid disease commences at the roots, 

 spreading up from thence to the layers of wood immediately sur- 

 rounding the pith, which in the course of a few years become soft 

 and rotten. | This disease has proved very destructive to Larch, 

 and is commonly known as Larch-rot. Another form of fungus 

 attacks the stem and branches, kills the bark on which it settles, 

 but leaves the roots and interior healthy. § Disease also arises 

 from the absorption by the roots of deleterious matters in the soil 



* " It is a curious circumstance that none of the Himalayan Conifers produce any 

 quantity of resin, turpentine, or pitch, which may perhaps be accounted for bv the 

 humidity of the climate.— Sir J. D. Hooker, Himalayan Journals, II. 45. 



t Chambers' Encyclopaedia of Useful Knowledge. 



% Rev. M. J. Berkeley, in Gardeners' Chronicle, 1859, p. 1015. 



§ Idem, 



