158 FORESTRY INVESTIGATIONS U. S. DEPARTMENT OF AGRICULTURE. 



Two methods of boxing are practiced, which are known as gemmage a mart and gemmage a vie, 

 or " bleeding to death n and " bleeding alive." The difference lies in the number of scars inflicted 

 simultaneously. The bleeding to death is applied to trees which are to be cut out in the thinnings 

 of a regular forest management and to those which are at the end of their usefulness. The illus- 

 tration (PI. XXX), here reproduced from Prof. L. Boppe's work on Forest Technology, represents a 

 pine 200 years old, with more than fifty scars or chips, without apparently any ill effects on the 



life of the tree. 



The "bleeding alive" is practiced on those trees which are to grow on, and hence must not 

 be injured too much. They receive, therefore, one chip at a time. When this, after five seasons' 

 workings, has attained a height of about 12 feet, the tree is allowed a rest of several years, and 

 then another chip is opened, 6 or 8 inches from the old one, or else on the opposite side of the tree. 

 In this way in time the whole circumference is chipped in alternating periods of bleeding and of 

 rest until the trees are to be cut for lumber, when 100 to 125 years old or more. Sometimes excep- 

 tionally vigorous trees receive more than one chip at a time, but these are opened at different 



heights. 



This successfully continued bleeding can, however, be carried on only by corresponding care in 

 the manipulation. The important difference between French and American practice consists in 

 this, that the former is more careful in the chipping and proceeds more slowly in enlarging the 

 chip, which is made only 3 to 5 inches wide instead of 12 or 14. Further, in collecting the products 

 with more care, the deep box cut into the tree in American practice is dispensed with and a lip 

 and pot substituted. 



The chipper begins his work in February or March by removing with a scraper from the whole 

 portion of the tree that is to be chipped during the season, about 2 feet in height by 4 inches wide, 

 the outer bark nearly to the wood. This is done to obviate the falling of bark chips into the pot, 

 thus securing a cleaner product, and also to save the chipping tool. In the first week of March 

 the chip is opened at the foot of the tree by making a triangular incision 3 to 4 inches wide and 

 about li inches high, and not deeper than two-fifths of an inch. (Note the small size of the open- 

 ing.) This chip is made with a specially and curiously fashioned hatchet, having a curved blade 

 and a curved handle, difficult to make and use (PL XXX, fig. 1). The chip is enlarged (chipping 

 piquage) without increasing the width or even decreasing it. The art of the chipper consists in 

 taking off just as thin a peel of wood as possible, and at each chipping he freshens up the old scar 

 by removing another peel, taking care not to go deeper than two-fifths of an inch altogether. 

 This chipping is repeated forty to forty-five times during the season, and during following seasons 

 the chip is carried higher, until it reaches 12 to 13 feet in height, namely, 70 inches the first season, 

 30 inches each the following three seasons, and 38 inches the last season, when the tree is left to 

 rest, and the wound heals up by the formation of new layers of bark and wood. 



The cross-sections of trees bled through several periods twenty-four to twenty-seven years, 

 and more (shown on PL XXXI) exhibit the manner in which the chips are distributed through the 

 various seasons around the tree, and the manner in which the scars heal over. To be sure, the 

 wood formed on the chips is irregular and therefore not serviceable for anything except fuel. 



An experiment made in Austria on the black pine with the Hugues system (PL XXXI) produced 

 more dip and less scrape and that purer, and with less work, owing to the greater capacity of the 

 vessel and the smaller surface to be scraped being confined to the chip of the year. Besides, 

 quantity and quality of the spirits and rosin were superior, namely, 78.5 pounds distilled gave — 



Spirits turpentine . . . 

 Eosm 



Water 



Scraps 



Loss by evaporation 



Common method 



Pounds Pei ct 



14. 7 or 18 78 



47 3 60 22 



30 6 Id 44 



15 1 96 



4 4 5 60 



78. 5 100 



Pot gathered. 



Pounds. Per ct 

 17 6 or 22 41 

 52 9 67.37 

 5 3 6. 72 



2 7 3 50 



78, 5 100 



Yield. — In a growth of 45 years of age, each tree produces from G to 10 pounds of resin each 

 season more than we obtain from old trees. The yield per acre varies, of course, according to the 



