DRY ROT

A disease which attacks wood, rendering it brittle, and destroying the cohesion of its parts, is known by this name. It occurs among the timbers of ships, where it sometimes commits the most serious damage, and in damp ill-ventilated houses. It is usually ascribed to the attacks of fungi, especially to such as Polyp or us destructor and Meruliits lachrymansy whose filamentous spawn or thallus appears upon the surface, overspreading it like a lough thick skin of white leather; and there is no doubt of its being often connected with the appearance of such funs i. But dry rot is certainly, in some cases, to be identified wilh the presence of fungi of a more simple kind than those just mentioned; especially of such as belong to or resemble the genus Sporotrichum. The destruction of timber by such plants is effected ir part by the disintegration of the tubes of the weed, in consequence of the introduction between them of the fine filamentous spawn of the fungi, and in part by the dampne which is thus conveyed to the interior of the wood, where it soon produces decomposition. It is not, however, certain that dry rot is always caused in this manner; on the contrary, the term appears to be frequently applied to cases of spontaneous decomposition of timber without the pre- [s. 382]