Merulius Lacrymans Research Articles

Dry-rot Fungus

THE “beautiful growth of fungus covering the wall and floor (in a wine-cellar) to a depth of 4 inches, suggesting cotton-wool in form and colour,” referred to by “M. H. M.,” is the destructive dry-rot (Merulius lacrymans), and I would advise your correspondent to make war upon it without delay. The cotton-wool form is an early stage of the fungus. If neglected, it will in a few months develop a leathery sheet, sending out tough leathery cords a quarter of an inch thick, with spore-bearing folds of a rusty colour. These spores will scatter themselves all over the cellar, and will be difficult to eradicate. The mycelium of the fungus buries itself in any kind of wood, especially deal, runs rapidly down the longitudinal fibres, and, as it goes, destroys the “nature” of the wood, so that it snaps and crumbles under the slightest pressure. I have had to deal with this pest in a range of cellars with a timber roof, and have found the best remedy to be repeated applications of corrosive sublimate dissolved in methylated spirit freely painted on the timber, walls, or floor, wherever the “cotton-wool” makes its appearance. I had to cut away 8 feet in length of a 10-inch Memel beam which was permeated by the mycelium, and rotten to the core. Between the end of this beam and the back of the recess in the brick wall in which it rested was a vacant space filled with the mature fungus full of spores. This was two years ago. I have been fighting the fungus ever since with the corrosive sublimate, and have nearly, exterminated it. The first appearance of the cotton-wool should be attacked without delay.