— n6 — 



height, as compared with incisions of from i" to i 1 ^" depth and 

 1 W to V2" height made by the process now in use. The further 

 advantage of the modified system is said to consist in the fact that 

 a given forest area, instead of being exhausted as at present in from 

 4 to 5 years, can be worked for turpentine for from 15 to 20 years 

 and even for twice that length if it is desired to exhaust the trees 

 to the uttermost before lumbering. Further, instead of from 19 to 

 2O°/ , it is said that the resin will yield from 22 to 2 5°/ of oil, 

 while the vitality of the trees is affected in the smallest - possible 

 degree, and is not destroyed. Further experiments to be made by 

 the Forestry Department will clear up the point whether young trees 

 not yet fully grown can also be turpentined by the new process 

 without damage to their development. 



In continuation of its efforts to introduce a less destructive treatment 

 of the turpentine producing trees, the American Forestry Department, 

 through its expert Mr. A. L. Brower, has published a treatise on the 

 method of turpentine- preparation which ^prevails in France. This has 

 also appeared in the periodical referred to above. 1 ) The French process 

 makes it possible to tap the same tree for 30 years or more without 

 injurious consequences and without reducing the yeld of turpentine. 

 By the old American "box" method, on the other hand, the tree 

 yields resin for 5 or 6 years only, and by the new "cup-and-gutter" 

 method, by which the trees are tapped lengthwise, from 15 to 20 years. 

 It must be admitted that the French process does not yield so large 

 a result as the American. It is also more laborious and requires work- 

 manlike practice; and in view of the entirely different economic 

 conditions of the two countries, it is extremely doubtful whether the 

 American forest owners will ever adopt the French method. 



The salient features of the French method consist in stripping the 

 trees as far as necessary of their outer bark, and in not beginning 

 to tap the trees until they are at least 15 years old. About the 

 beginning of March a tapping-space is cut into the trees quite close 

 to the ground by means of an axe of particular shape with a 

 convex cutting edge placed at right angles to the axis of the shaft. 

 This tapping surface is about 1 / 2 " deep and about 4 sq. in. in area. 

 Below this spot a curved cutting is made with a chisel and in 

 this a bent strip of tin, shaped like a trough, is placed for the 

 purpose of receiving and conducting the resin. Below this, wedged 

 in between the strip of tin and a nail driven into the tree, is the cup 

 intended for collecting the resin. Between March and the middle 

 of October the tapping place is enlarged about 30 times in an upward 

 direction, each time from 1 / 2 " to 1", the depth of the incision ( 1 / 2 // ) 



x ) Oil, Paint and Drug Reporter 75, No. 18, p. 28, 3rd May 1909. 



