144 WOODS OF COMMERCE. 



otherwise. To preserve the finer pieces from insect attack they 

 are sometimes, in Scotland, immersed for some months in peat- 

 water, to which some lime is added, which gives the wood some 

 resemblance to Mahogany. It has then been used for tables. 

 Alder was formerly used for piles, water-pipes, sluices, etc , but 

 Elm, being far more durable when alternately wet and dry, is 

 much better for such purposes. The piles of Ravenna, according 

 to Vitruvius, and those of the Rialto at Venice, and those of 



Fio. 45. Transverse section of Alder (Alnus glutin6sa) highly magnified. 



Amsterdam, according to Evelyn, were largely of Alder, and 

 Pliny speaks of it as " eternal " when so used. Alder is employed 

 for packing-cases, the staves of herring-barrels, shovels, clogs and 

 sabots, bobbins, barrows, kneading-troughs, etc. The roots and 

 knots, being often handsomely veined, are used in small articles 

 of turnery and cabinet-making. Alder is practically the best 

 wood for gunpowder-charcoal. It is imported from the Baltic 

 ports of North Germany, where there are extensive pure forests 



