MANILA COPAL. 185 



Direct acid and complete saponification determinations in duplicate 

 gave the following numbers : 



Sample No. 

 1 



Acid value 

 milligrams potash. 



109.0 



Saponification value 

 milligrams potash. 



148.0 



2 



105.7 





145.3 



3 



134.2 





184.4 



4 



131.1 





181.2 



STEAM DISTILLATION OF THE CRUDE KESIX. 



One-half kilogram of coarsely powdered surface resin was subjected to 

 steam distillation, but only traces of a volatile oil could be recovered. 

 The mineral resin, which admitted of much finer pulverization, yielded a 

 larger portion of its content of volatile oil. 



A large, irregular mass of the very pliable resin (samples Nos. 3 and 4 

 above) also yielded a trace of oil to exhaustive steam distillation. 



Upon the addition of alkali in slight excess of the amount required to neutral- 

 ize the resin, and continuing the distillation, from 500 grams of surface resin 

 (sorts) there were obtained 6.5 grams of oil or 1.3 per cent; from mined resiu 

 (bold pieces), 40.0 grams of oil, or 8 per cent; from soft resin (sample No. 3), 

 56.0 grams of oil, or 11.2 per cent. 



It is seen from the above that the state of aggregation rather than the age 

 of the resin influences the proportion of volatile oil which can be isolated 

 by steam distillation; the soft, pliable product and the brittle, bold piece of 

 mined copal containing a much larger proportion of volatile terpenes than 

 did the small, friable pieces obtained from living trees by artificial means. 

 Examination of the volatile oil for possible differences due to the above 

 sources was not made. The combined fractions, dried over solid potash, 

 gave a pale, lemon colored oil of very pleasant odor. Specific gravity 



^ = 0.865; N^!_ = 1.4648; A^- =— 26.55. The oil was distilled over 



sodium, the main fraction boiling from 155° to 165°, leaving about 10 

 per cent by volume above 165°. 



The fraction from 155° to 165° was converted into a hydrochloride 

 which recrystallized from alcohol in needles melting at 12-4° and which 

 was identified as pinene hydrochloride. For further examination of 

 the terpenes from Manila copal see Brooks, This ■ Journal, Sec. A 

 (1910), 5, 205. 



The main objection to Tschirch's method of examining resinous sub- 

 stances is its inapplicability to resins which are not completely soluble in 

 ether or some other solvent indifferent to aqueous alkalies. Furthermore, 

 the difficulty of complete removal and separation of the weak resin acids 

 from their etherial solutions with dilute solutions of ammonium and 

 sodium carbonates renders the method extremely tedious and unsatis- 

 factory. 



