92 PRACTICAL ARBORICULTURE 



The cheapest and most common process is that used by the Rock Island, Santa 

 Fe and other railways, where the basis is chloride of zinc, a by-product of the 

 smelters. 



Fermenting sap of the wood is removed by steam in a large iron boiler, 

 after which the solution of zinc and other substances is forced into the empty cells 

 of the wood, under pressure with steam. Soft wood with open grain is preferred 

 for this treatment, and many years are added to the durability of the wood by 

 this means. The capital invested in such a plant would produce a regular and 

 remunerative income for the company. 



The practice of cutting very small and immature pine and spruce trees, of 

 which the managers of your lumber company have destroyed so much, should 

 cease at once. I saw Mexicans cutting pines which were but five inches diam- 

 eter at the stump, and this in large numbers, for mine props. 



Such wood decays quickly, and forever prevents a forest growth. When 

 trees have grown for twenty years and have become of this size, their future 

 increase will be far more rapid. Hundreds of acres of young forest trees have 

 in this way been utterly destroyed, without any corresponding benefit. 



INSECT DEPREDATIONS. 



Two prominent insects which destroy the yellow pine are present in the 

 timber upon the grant. The large, destructive bark beetle and the small beetle. 

 I collected specimens and sent them to the entomologist of the United States. 



These are flying beetles, the egg is deposited in the bark, and hatches into 

 a worm or larva, which lives upon the cambium or inner tissue of the bark. 

 As it burrows about the tree, it finally completely girdles it, so that no sap can 

 circulate and the tree dies. In time this larva is transformed into a winged 

 beetle, which, emerging from the bark, goes to other trees, depositing eggs in 

 great numbers. When these beetles become very numerous, the trees are killed in 

 such numbers as to threaten the entire destruction of the pine. Fortunately 

 their numbers are small yet, on the grant, and held in check by parasitic enemies, 

 and very largely by woodpeckers, which birds should be protected. 



I recommend that every dead tree be cut, the bark stripped off and burned, 

 together with the tops, branches and stumps. The wood is suitable for lumber, 

 if not too far decayed. At present there is no cause for alarm in this vicinity. 

 Some pine-leaf scale is present, but not in great quantities. By protecting all 

 birds, there need be no fear of serious insect injury. 



PASTURAGE BY GOATS. 



Spain was once the peer of any nation. Her downfall, although requiring 

 centuries for its accomplishment, was caused by so insignificant an animal as the 

 goat. Clearing the forests from her mountains, nature in time would have reaf- 

 forested them, but immense herds of goats were pastured on these hills, destroy- 

 ing every living tree and shrub. 



Mexican goats are performing like destruction on the mountains about Las 

 Animas and other portions of your grant. It will always be impossible to preserve 

 any tree growth where these animals are fed. 



