DURABILITY OF RESINOUS WOODS. 679 



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 inva- 

 lid class, who have obtained a restoration of health here ; that thou- 

 sands, 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 RESIN'OUS WOODS. 



Bt HEINEICH mate, 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 pre- 

 senting to the readers of the " Monthly." In face of the confusion 

 prevailing in the nomenclature, it is necessary to state that the botani- 

 cal names used are those of Carri^re in his " Traite des Conif^res," 

 who separates Abies and Picea as distinct genera. The distribution 

 of the resiniferous ducts is so characteristic within each of these gen- 

 era 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 



