OLEORESIN PRODUCTION. 



9 



It is customary to cut from 28 to 40 streaks each season. Often 

 one-third of the trees in a commercial operation die, chiefly because 

 of the undue severity of the methods used in turpentining. In some 

 places the old method of cutting boxes or cavities at the butts of 

 the trees (PI. I, fig. 1) to hold the exuding gum, is still used, al- 

 though, for the most part, cups of various types are employed (PI. 

 I, figs. 1, 3, 5, and 6). 



After chipping, the gum or oleoresin exudes from the freshly cut 

 surface. The most abundant exudation (88 per cent) has been 

 observed to occur during the first three days after chipping. 

 (Table 1.) 



Table 1. — Rate of exudation of gum from chipped longleaf pine. 1 



Day. 



Grams of 

 gum. 



Total 

 exudation, 

 per cent. 



First 



113.0 

 22.5 

 13.5 

 9.0 

 9.0 

 1.0 



67.26 





13.39 



Third 



8.04 



Fourth 



5.36 





5.36 





.59 







Total 



168.0 

 (=0.37 lb.) 



100.00 











1 For. Sen . Bui. 90, p. 6. 

 SIGNIFICANCE OF RESIN PASSAGES PRESENT IN THE UNTURPENTINED TREES. 



The gum which exudes during the first weeks of a virgin or first- 

 year operation comes from the normal resin passages which were al- 

 ready present in the round or unturpentined timber. Plate II, figure 

 1, shows the characteristic condition of the trees at Columbia, Miss., 

 on April 13, 1916. At that time no new wood or resiniferous tissue 

 for the 1916 ring had formed. Plate II, figure 2, shows a cross sec- 

 tion cut from a tree on June 13, 1916. The development of new wood 

 cells is apparent, and new resiniferous tissue may be seen to be dif- 

 ferentiating in the region next the cambium. Plate II, figure 3, shows 

 a cross section cut from a tree on July 5, 1916. Marked differences 

 '•n individual trees occurred, however, and the range of develop- 

 ment of the 1910 ring shown in the three figures might be encoun- 

 tered in material cut at the same time from different trees during 

 either lute May or early June. Often it is the end of May before the 

 new ;m<! augmented development of the resiniferous tissue, formed 

 after wounding in the new wood, is sufficiently advanced to yield 

 appreciable amounts of resin. Indeed it, frequently happens that in 



;i virgin operation (In- normal resin passages present in Hie round 



timber may fill the cups not only for the first but also for the second 

 and sometimes for the thud time, or " dipping, 4 ' before any new resin 



