Page:Popular Science Monthly Volume 28.djvu/697

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679
DURABILITY OF RESINOUS WOODS.

are the sole desiderata in selecting a suitable climate; or, on the other hand, that equability of temperature should alone be considered.

Writers may still object that we have high winds and sand-storms, which annoy the visitor; or that "the enormous monthly and also diurnal range of temperature must severely try any man"; or raise one objection after another on merely theoretical grounds: and yet the fact remains—a fact that rises superior to all argument and cavil, and which is in itself the most conclusive argument that can be advanced—that a large percentage of our population is made up of the so-called invalid class, who have obtained a restoration of health here; that thousands upon thousands of lives have been saved to the world, not to drag out an invalid's existence, but rather to take a manly part in the struggles of life, simply by coming to Colorado; and that to-day there are living within its borders persons, to be numbered by the tens of thousands, who would undoubtedly be glad to attest their gratitude to the climate by saying of it, as the writer thinks he can truthfully say, "It saved my life."

 

DURABILITY OF RESINOUS WOODS.
By HEINRICH MAYR, Ph. D.

THERE can be no doubt that the resin in the wood derived from the different varieties of conifers, or pine-trees, is one of the most important factors which determine its quality, especially its durability and resistance against the influence of weather and the different forms of rot, all of which are now proved to be due to specific fungi. Just at present, timber from American conifers is highly valued in Europe, because of its richness in resin, although the amount of resin in wood is not the sole measure of its quality.

Until now an exact valuation of the importance of pitch in wood was impossible, because the accurate knowledge of the origin and the distribution of the resin, as well as of the arrangement of the organs producing it, was wanting.

At the experimental botanical station at Munich, I have made numerous experiments during a space of many years, and, as the results seem to contain many new points, I thought them worth presenting to the readers of the "Monthly." In face of the confusion prevailing in the nomenclature, it is necessary to state that the botanical names used are those of Carrière in his "Traité des Conifères," who separates Abies and Picea as distinct genera. The distribution of the resiniferous ducts is so characteristic within each of these genera as to serve as typical marks for them.

The species of Abies commonly called firs are characterized by the absence of resiniferous ducts within their woods; it is only in rare