DRY ROT. A popular name for the decay of timber after it has been seasoned. Dry rot is usually slow in its action. though under some eircum-tam-es it may he rapid and destructive, edifices and can-ing serious accidents. Dry rot is caused by the fungus 7derulius lachry mans. Somewhat similar effects are due to tain specie, of Polyporus. The disease is quite connnon in timber that is exposed to moisture. as the ends of joists set in damp walk, wains coting about sinks. etc. The timber is ultimately to powder within a thin surface shell of sound wood. Although called dry rot. awi-tnre is essential for the development of the fungus that causes it. The spores germinate and send their mycelium through the wood in all diree tions. attacking and destroying the wood fibres. At first the fungus appears as a thin white film which gradually thickens at the centre and changes to a rusty brown color. A kind of timber known as red striped shows the beginning of dry rot. Perfectly sound timber may beeome infested by spores gaining entrance through cracks in the ends of log-. 1%Itich. when wet, sw?ll up. It the moisture be con-tant. the dry rot to grow. Weakening the timber.
1 fie timber may dry out without destroying the 1110i-1111'e pet -Cat. The use of some kinds of sound-deadening material. such as wet etc., I Vnralde in the tdOinnent on dry rot. Ifni% dry gravel or coarse sand should be used. Coal-cinder-. cte., are alkaline, and the spores of rMertilins Ifiehry can be germinated only in the presence of alkalies. 'limber that is \\ ell seasoned and pro by paint will not be attiu•ked by dry rot.
.1 Wandler of fungi attack the N\ ( )4)41 Of I. What i, Called dry rot. Most of these fungi belong to the class of toadstools and shelf and seriously de structive. This form of rot is caused on apple tree• by l'olyporus hispidus: ru oak, alder, poplar, I.R•st. and larch by Polyporus sul phurens: on larch, Scotch and \dike pine. by Polyporus Seim( initzii: on ...miters by romes pinicola. etc. 1).edalea miercilm is a common saprophyte upon oak-stumps and oak:Alves. The mycelium of this species forms leathery mats and is bellt ved to be parasitic. The dceompos oak wood as-nines a grayish broxvn