THE BIRCH. 



81 



possesses another advantage in being of quicker 

 growth, and attaining a larger size. There is also 

 a slight difference in the leaves, which are smaller 

 and somewhat downy. Sir W. J. Hooker ob- 

 serves that the branches are more w^arty in the 

 Weeping Birch than in the common kind, and 

 Sir T. D. Lauder has noticed that the fragrant 

 gum or resin, which exudes from both varieties, 

 hardens on the spray of the Weeping Birch, and 

 causes a rough appearance. 



The Birch is a tree of rapid growth, especially 

 when young ; and as it is little affected by ex- 

 posure, it forms an excellent nurse for other 

 trees. The soil which it prefers is turf over sand, 

 and in such situations it attains maturity in about 

 fifty years; but it seldom exceeds fifty feet in 

 height, with a trunk from twelve to eighteen inches 

 in diameter. The bark possesses the singular 

 property of being more durable than the wood 

 which it encircles. Of this the peasants of 

 Sweden and Lapland, where Birch is very abun- 

 dant, take advantage, and, shaping it like tiles, 

 cover their houses with it. Travellers in Lapland 

 have noticed in the Birch-forests, that when the 

 soil is very scanty, the trees are liable to be 

 blown down ; so that, in some places, as many 

 are seen lying on the ground as are left stand- 

 ing. Such as have lain long are found to have 

 entirely lost the substance of the wood, the 

 bark remaining a hollow cylinder without any 

 symptom of decay. Li North America this 

 durability of the bark is turned to good ac- 

 count. The Canadians select a tree with a 

 large and smooth trunk. In the spring two 

 circular incisions are made quite through the bark 



II. G 



