Boiling point, 

 degrees (6 mm.) 



(1) 



51 



-51 



(2) 



51 



-52 



(3) 



52 



-52.5 



(4) 



52.5-54 



(5) 



54 



-57 



(6) 



57 



-60 



PHILIPPINE TERPENES AND ESSENTIAL OILS, III. 101 



The total yield of terpene oil was 14 per cent. The greater part of 

 these terpenes consisted of phellandrenes, although in the higher boiling 

 fractions, dipentene (present only a very small amount) could be detected 

 by the formation of dipentene tetrabromide melting at 124°. It is 

 evident from the two above-mentioned distillations that there is very little 

 decomposition caused in pliellandrenes by distilling them at ordinary 

 pressure. To test more thoroughly the effect of such distillations, 2 kilos 

 of the same lot of elemi resin were worked up just as in the above experi- 

 ments, save that all distillations were made in vacuo. After the second 

 distillation of the terpene oil, the following fractions were obtained, each 

 number representing about 55 cubic centimeters of oil in a 10-centimeter 

 tube. 



Optical rotation, 10 cm. 



30° 

 tube, N — (degrees) . 



101 

 101 



98 



93 



83 



83 



This experiment shows that there has been a slight lowering of ■ the 

 optical activity of the phellandrene due to distillation at ordinary 

 pressure. This has been my experience in other experiments. In 

 repeatedly distilling 300 grams of a phellandrene, I have noted, after 

 each distillation, that the optical rotation is lowered by 0°.5 to 1°.0. 

 Ifone of the other constants of the terpene are affected, and phellan- 

 drenes are not as sensitive to heat as would be judged from the state- 

 ments on this subject in the literature. Sunlight affects the optical 

 activity of phellandrenes much more markedly than heat, as is shown by 

 the following: 



Sample 55, Calaoag resins, o phellandrene. Rotation in ai 10-centimeter tube, 

 134°.5. After two hours in the sunlight, 132°.0. After eight hours more of 

 sunlight, 124°.7. 



Sample 69, a phellandrene. Rotation in a 10 centimeter tube, 125°. 5; after one 

 week's exposure to the sun 101°.5. 



Sample 99, /3 phellandrene. Optical rotation in a 10-centimeter tube, 78°. 7. 

 After one week's exposure to the sunlight, 32°. 1. This phellandrene had then 

 become markedly thicker and more viscous. Pesci " obtained a glassy mass 

 (CioHm)*, melting at 86°, by heating /3 phellandrene for twenty hours in a sealed 

 tube from 140° to 150°. The /3 phellandrene from elemi is not nearly as sensitive 

 to heat as this phellandrene from waterfennel oil, which Pesci used. 



Sample 90, a limonene. Optical rotation in a lO-centimeter tube, 96°.0. 

 After one week's exposure to the sunlight, 94°. 9. Sunlight, therefore, has very 

 little effect on limonene. 



^''Gazz. chim. ital. (1886), 16, 225; Ber. d. devtsclien chem. Ges. (1886), Ref. 

 19, 874. 



