ARIZONA EXPERIMENTS ON WESTERN YELLOW PINE. 



11 



Area A produced considerably more scrape than areas B or C. 

 This is accounted for in part by the fact that about one-third of the 

 faces on A were worked for six weeks in the preceding year (1910). 



COMPARISON OF YIELDS OF DIP AND SCRAPE FROM BLACK JACK AND YELLOW PINE. 



The yields of dip and scrape from both black jack and yellow pine 

 are shown in Table 6 : 



TABLE 6. Weight of dip and scrape obtained from blackjack and yellow pine. 



BLACK JACK. 



YELLOW PINE. 



On areas A and B the black jacks gave a larger flow per cup than 

 the yellow pines, while on C this was reversed. But including all 

 trees of both classes the average yield per cup was practically the 

 same. The production of scrape on area A was considerably larger 

 per face for black jack than for yellow pine; on B and C the produc- 

 tion per face was about the same for both classes of timber; taking 

 all areas, therefore, the production of scrape ran slightly higher for 

 black jack than for yellow pine. 



COMPOSITION OF DIP. 



The results of 22 analyses of samples of crude gum are shown in 

 Table 7. These analyses show only the proportions of volatile oil, 

 rosin, water, and chips in the crude gum. Ordinary turpentine from 

 the southern yellow pines consists almost entirely of pinene. A 

 further analysis * of the volatile oil from gum obtained in Arizona 

 shows it to be mostly pinene with a small proportion of a higher 

 boiling terpene not found in ordinary turpentine. There is no appar- 

 ent reason why Arizona turpentine can not be used commercially with 

 entire satisfaction. The same is true of the Arizona rosin. 



i Forest Service Bulletin 119, An Examination of the Oleoresins of Some Western Pines, by A. W. 

 Schorger. 



