DRY-ROT

A peculiar disease that attacks wood, and renders it brittle and rotten. It is generally caused by dampne and the subsequent development of the spores of fungi, particularly those of Merulius lacrymans and vast at or and Polyp or us destructor . The dry-rot principally attacks ‘ill-seasoned’ timber, and more particularly that of ships and badly ventilated buildings. Prev. Various means have been proposed to prevent the attacks of dry-rot and to arrest its progre when it has commenced, among which the proce called ‘ Kyanizing ’ (Kyan’s patent) is that most generally known and most extensively adopted. It consists in immersing the timber in a bath of corrosive sublimate. The proce termed ‘ Paynizing ’ (Payne’s patent) consists in first filling the pores with a solution of chloride of calcium, under pre ure, and next forcing in a solution of sulphate of iron, by which an insoluble sulphate of lime is formed in the body of the wood, which is thus rendered nearly as hard as stone. Wood so prepared is now largely employed in our public works and railways. Sir W. Burnett’s proce (patented in 1836) consists in impregnating the timber with a solution of chloride of zinc. Mr J. Bethell’s proce (patented in 1838) consists in thoroughly impregnating the wood with oil of tar containing creasote and a crude solution of acetate of iron, commonly called ‘pyro lignite of iron.’ The impregnation is effected in a strong cylindrical ve el, connected with a powerful air-pump, so that in the first instance a vacuum being formed, and subsequently a pre ure of several atmospheres applied, the liquid may as much as po ible be forced into all the pores of the wood. The above proce es for ‘seasoning’ preserve the timber not only from dry-rot, but from the influence of the weather and the attacks of insects and worms. “The construction of air-drains or pa ages around wood-work to be preserved is, where the method is applicable, a great aid to the preservation of wood. Dry-rot is both prevented in new buildings and cured in old ones by filling up the spaces between the floor-joists with ‘tank-waste’ from alkali works. This can also be applied to the ends of beams resting in walls.”— Chemical News.