Wood Preservation 



like the taste of treated wood, though this attenuated crustacean 

 bores his way through the hardest of wood (except green heart) 

 that is not medicated to discourage him. 



Trees that fall in bogs and lakes lie too far down for destruc- 

 tion by fungous organisms. The water-soaked fibres have their 

 protoplasmic contents dissolved out, and mineral substances 

 held in the water are deposited by slow degrees. Bog oak of 

 Ireland is black as ebony from bark to pith. It is also heavy 

 by the weight of the mineral substance that impregnates its 

 cells. Wood impregnation by natural processes reaches its 

 highest perfection in the petrifactions that occur. The petrified 

 forest of Arizona contains trees which preserve their form and 

 structure, even to wood rings, but silica has been infiltrated to 

 the utmost cell, turning the whole tree into agate, chalcedony 

 or other forms of quartz. Montana has an extensive forest of 

 trees turned to stone of a translucent, opaline character. The 

 colours are blue, white and smoky black. Doctor Merrill of the 

 National Museum found this forest in 1903, and his report wisely 

 withholds its location. It is scarcely desirable that this remark- 

 able opalised wood should be nabbed by a syndicate and cut up 

 into paper weights — a fate that has overtaken the fossil forest of 

 Arizona. 



Paint gives effectual protection to wood exposed to the 

 weather, with its alternation of heat and cold, sun and rain. 

 It needs renewing every few years. The basis of paint is oil — 

 pure linseed oil being the best. Ground pigments mixed into 

 the oil until it has the consistency of rich cream supply colour 

 and filling. The paint applied, the oil soaks in and fills the wood 

 cells, while the pigments form a protective layer, or film, over 

 the surface. When this layer cracks and scales off, a fresh 

 painting is needed Oil alone is a protective covering. Or oil 

 may be left out, and pigments dissolved in other liquids may be 

 applied. Whitewash is a familiar example of this treatment. 

 All such applications last but a short time. In the chapter 

 that follows some account is given of the processes that preserve 

 wood and at the same time beautify it. 



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