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every way competent to fill the sap cells of timber with preservative substances, and in no 

 case at the expense of mucli power. Such an arratigement would, besides, be eminently 

 adapted for the coloring and hardening of wood for cabinet work, pavements, railroads and 

 for various other purposes. With this view I have made some experiments which promise 

 well. I have also directed my attention to the protection of timber against the destractive 

 action of the ship worm, ( Teredo navalis,) on which subjects I intend, as soon as convenient 

 to report the results to the association. 



It may here be asked, what antiseptics are best adapted for reciprocal decomposition 

 when presented to each other within the walls of the sap vessels? The answer, as I view 

 the subject, is, that wood intended to be preserved by artificial means, if the saving of expense 

 be ail object, should, in the first place, be submerged in a solution of an alum composed of 

 oil of vitriol, (sulphuric acid,) iron, clay (or alumina) and water, or in one of common 

 copperas, (sulphate of iron,) until the sap cells have become filled, when it is to be removed 

 and thoroughly air-diied under cover. It may next be immersed in any saline solution that 

 will decompose that first applied, and when fully saturated be removed to a dry place under 

 cover and there be suffered to season till required for use. 



In lieu of the above named articles, blue vitriol (sulphate of copper) and common 

 alum, (super-sulphate of potash and alumina,) may be used, and to those which do not contain 

 an excess of sulphuric acid, a small quantity of this article may be beneficially added ; in 

 fact, if greatly diluted, it is of itself a powerful antiseptic. The solution in the second 

 reservoir, for completing the process, may be composed either of tlie acetate of lime or the 

 chlorate of lime, which on timber prepared as before described being placed in it, will 

 penetrate its sap cells and occasion a reciprocal decomposition of the salts used. 



If copperas be used in the first place and acetate of lime in the second, sulphate of 



lime and acetate of iron will result. The former in combination with the prot-oxide of 



iron is insoluble and alone sufficiently so to answer the purpose of its application, viz. : the 



closing of the sap vessels. The latter will remain in a fluid state till the aqueous portion 



evaporates, but in every state subject to be decomposed by oxygen as far as it may be 



present. Hence, it is one of the most valuable antiseptics that can be provided, because 



decomposition cannot take place unless this gas be present, and this salt (acetate of iron) 



will continue to absorb or combine with it till it is wholly decomposed or converted to a 



percetate. A change, protected as it would be by the woody fibres and by the partial closure 



of the sap cells, is not likely to take place in the course of many ages. 



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