EFFECT OF BLEEDING ON TIMBER. 161 



bore-hole, being 1 inch in diameter and reaching into the center, is closed with a wooden stopper. 

 This hole fills up during the summer and the resin is taken out with a half-cylmdrical iron and 

 then closed up. One tree will furnish per year one-fourth to three-eighths of a pound (120 to 180 

 grams) of resin. If the bore-holes were left open from spring to fall, the yield could be increased 

 to 1 pound, but the resin would be impure, would contain less spirits of turpentine, and the tree 

 would be damaged. One bore-hole suffices for the whole period of orcharding, which is usually 

 carried on for thirty years. With small amount of work and with a price two to three times that 

 of the black pine turpentine, and no injury to the trees, this industry is quite profitable in spite 

 of the small yield. 



GATHERING FIB TURPENTINE. 



The resin of the firs occurring mainly in isolated resu. vesicles or cells and most abundantly 

 near the bark (blisters), this is gathered by means of an iron pot with sharp-pointed till, with 

 which the vesicles are pierced. Erom the European fir in this way the Strasburg turpentine used 

 to be gathered; now the practice is nearly abandoned. The Canada balsam is gathered similarly 

 from our own fir, Abies balsamea. 



EFFECTS OF TURPENTINE ORCHARDING ON TIMBER, TREE, AND FOREST, AND SUGGESTIONS FOR IMPROVEMENT ON 



AMERICAN PRACTICE. 



The turpentine industry can be carried on, but usually is not, without detriment to the value 

 of the timber, to the life of the tree, and to the condition of the forest. The present practice, how- 

 ever, in the United States is not only wasteful but highly prejudicial to present and future 

 forestry interests. 



Effect on the timber. — As far as the timber of bled trees is concerned, it has been shown by the 

 work of the Division of Forestry that the heartwood, the only part of the tree which is used for 

 lumber, is in no way affected directly by the process of tapping. Not only has its strength been 

 shown to be in no wise diminished, but since the resin of the heartwood does not participate in 

 the flow, being nonfiuid, the durability of the timber, as far as it depends on the resinous contents, 

 can not be impaired by bleeding. Indirectly, however, by the boxes and large-sized chips, a con- 

 siderable loss of timber in the best part of the tree, the butt log, occurs, which is avoidable. The 

 parts surrounding the scar are furthermore rendered somewhat harder to work by an excess of 

 resin which accumulates on and near the wound, tending to "gum up" tools. Indirectly, also, a 

 considerable proportion of boxed timber becomes defective if not used at once or, if left on the 

 stocks exposed for a series of years to destructive agencies, such as fires, followed by fungus 

 growth and attack of beetles. The larvae of large Capricorn beetles bore their way through the 

 soft wood formed in the shape of callous surrounding the borders of the chip and through and 

 beyond the sapwood. Through the innumerable fissures which are caused by repeated fires, air 

 and water charged with spores of fungi find entrance into the body of the tree, causing decay, 

 the damage increasing every year, so that from this cause alone the timber from a turpentine 

 orchard abandoned for ten or fifteen years was at the sawmill found damaged to the extent of 

 fully 20 per cent. 



Another prospective loss in timber is occasioned by the tapping of undersized trees which are 

 not ready for the saw. Even if the tree survived all the changes of the years following the 

 bleeding and healed over the wound, the timber formed after the process, at least in the portion 

 of the tree which carried the chip, is inferior and not fit for sawmill purposes on account of 

 malformations and change of grain. The loss of timber by fire is also only an incidental effect of 

 careless management. 



Effect on trees, — No doubt the normal life of the tree is interfered with by bleeding; not that 

 the resin is of any physiological significance to the life of the tree, but the wound inflicted in the 

 tapping, like any other wound, interferes with and reduces the area of water-conducting tissue. 

 This interference may be so slight as practically to have no effect, or so great as to kill the tree 

 sooner or later if other conditions are unfavorable. The experience in France shows that with 

 care (narrow chips and periods of rest, which permit callousing of the scar) trees may be bled for 

 long periods and attain old age (see p. 158); it also shows how fast a tree may be bled to death, if 

 this is desired. (See PI. XXX.) 



XX. JL/OG. xOJL * JLX 



