IK) Mr Menteath on the Geology of Nithsdale. 



All the varieties of soil, however, of the Closeburn basin are 

 improved by lime ; and whenever larger doses of it are laid on 

 the soil, and a better system of husbandry generally pursued, 

 very great improvements may be expected in the general aspect 

 of the whole surface of the district. 



It may be worth while, as connected with the subject of soil, 

 to mention some curious facts respecting the growth, toughness, 

 and durability of different kinds of wood in the basin of Close- 

 burn, and which may perhaps be looked for in other districts of 

 Scotland similarly circumstanced. 



The Scotch fir, P'mus sylvestris, thrives well, but does not 

 grow fast on the soil over the sandstone. Its wood, however, is 

 tough and very durable. But when this same tree is planted 

 on the greywacke, though it grows more rapidly, and arrives 

 sooner at maturity, yet being softer and fuller of white wood 

 than that grown upon the sandstone, the builder, to his cost, 

 finds that it is soon attacked by the worm, and decays *. 



The reverse of this happens with the Larch, Pinus Lario', 

 when growing on the greywacke. Its wood is sound and good, 

 and, when cut down, is at heart quite perfect. But on the sand- 

 stones and gravels of this basin, it seems to be at maturity at an 

 earlier age than that growing on the greywacke, and, in many 

 instances, when cut down on these soils, the larch presents a 

 tubed, decayed heart. Under twenty years old such instances 

 of internal decay appear. And the remarkable thing is, that 

 externally to the eye the larch seems healthy and vigorous. 



We may here state that the larch grows naturally only on the 

 primitive mountains, as the granite, gneiss, and the like rocks of 



• Some remarkable facts respecting the durability that may be given to 

 timber by artificial means, have been observed at Closeburn. The proprie- 

 tor of that estate has for thirty years been in the constant practice of soaking 

 all fir and larch timber, after it is sawed into plank, in a pond or cistern of 

 water, strongly impregnated with lime. In consequence of this soaking, the 

 saccharine matter in the wood, on which the worm is believed to live, is either 

 altogether changed, or completely destroyed. Scotch fir wood, employed in 

 roofing of houses, and other indoor work, treated in this manner, has stood 

 in such situations for thirty years, sound, and without the vestige of a worm. 

 In a very few years, fir timber so employed, without such preparation, would 

 be eaten through and through by that insect. It might perhaps be advisable, 

 in all timber used for ship-building, to soak it for some days in lime-water. 



