Page:Popular Science Monthly Volume 29.djvu/631

Rh One important aid in the preservation of timber will be, for those whose duty it is to care for it, to acquire more practical knowledge of the fungi which grow on it, and this is not a difficult task. What is needed is to call the attention of the men to the conditions and to the prevention of the growth of fungi. The literature about it is meager, only foreign text-books having been published which describe the general species. Professor Charles H. Peck, in the reports of the New York State Museum of Natural History, from the twenty-third to the thirty-eighth, inclusive, has described a great many species of fungi, and has made the most important American publications to date. For practical use he has done a valuable work in the collection and mounting, in the State Herbarium, at Albany, of over twenty six hundred species, where one can in a short time learn to identify the ordinary species found upon ties and timber. In the Columbia College Herbarium there is a collection of nearly three thousand species of the general fungi of this vicinity, which is also open for study. The facilities for taking up the practical work are abundant. Every railway company has men of sufficient aptitude to learn to identify species and study their conditions of growth, and form from, the materials which can be found upon every mile of their lines, collections of decayed wood, from which the employés can gain knowledge to be put into daily practice to check much of the unnecessary decay of all their wood-work of ties, bridges, cars, and buildings.

The cheapest operation to protect our woods, and quite sufficient for many purposes, is to season or thoroughly dry the timber, reducing the contained moisture from eight to twelve per cent of the weight of the wood; and when in this condition, with a circulation of air around it, to prevent the collection and absorption of moisture, the wood will last indefinitely, as the fungi can not grow in such surroundings. Every one is more or less familiar with the soundness of timber in the upper parts of buildings, while in lower parts near the foundations it is often decayed on account of moisture.

In many situations, however, where timber must be used, the conditions of growth of the fungi are present, and it will decay; some species can be used which resist the attacks of the fungi for a long period, but the final result is decay unless the wood is treated by some process preventing the growth of the fungi, which must be capable of doing either one of two things: 1. It must keep the fibers dry, preventing the absorption of moisture. 2. If the wood must be in a damp place and kept moist, some antiseptic must be present, sufficient to prevent the growth of any of the various kinds of destructive fungi. Timber entirely submerged does not come under these considerations. To use the first process successfully means more than a thin coat of paint or tar on seasoned wood when exposed to continued moisture. It must be some substance which penetrates the tissues of the wood sufficiently far, in case the exterior surface is broken, to prevent any