206 



BROOKS. 



content of volatile oil therefore does not always indicate the real age 

 of the resin. Eesin on the surface and interior of the same piece may 

 be of quite different age with respect to the chemical changes which 

 have taken place during the ageing process. 



In order to investigate the terpene fractions more fully, several 

 distillations were made on different specimens. The fractions boiling 

 between 154° and 180° were as follows: 



Small, hard, light-colored pieces 



Large, hard, dark-colored lump with very friable surface 



Large, hard, light-colored lump 



Fresh, soft, white pieces 



Per cent. 



3.6 



6.0 



10.0 



11.2 



The volatile oil obtained from the soft, white material was shaken 

 out with caustic soda, dried, and distilled over sodium. The following 

 fractions were obtained : 



155°-162°. 



162°-168°. 



16S°-170°. 



170°-1£0°. 



Residue. [ 



Grams. 

 145 



Grams. 

 16 



Grams. 

 6 



Grams. 

 12 



Grams. 

 6 1 



The fraction from 155° to 162° consisted largely of pinene. It possessed the 



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following constants: Specific gravity ^=0.8487; N^-=1.4672; A°^-= 12.10°. 



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The presence of pinene was proved by the preparation of pinene nitrosyl chloride, 

 which was identified microscopically. The nitrosyl chloride was then treated 

 with benzylamine and the crystalline pinene nitrobenzylamine identified by its 

 melting point, 122°-123°. This fraction was redistilled twice over sodium and 

 about 90 grams were obtained which boiled between 155°. 5 and 158° and showed 



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the specific gravity ^_ = 0.8486; N^-=1.4655; A^- = 15°.50. 



It was always noted in the distillates from all the samples that a large portion 

 of the terpene fractions boiled from 160° to 165°. The fractions boiling from 

 160° to 170° which were obtained from all the samples were united and frac- 

 tioned. 



The fraction boiling from 160° to 161° was tested for camphene according to 

 the method of Bertram and Wahlbaum. 12 On slowly subliming the mixture of 

 terpineol and isoborneol which this method yielded, crystals of isoborneol were 

 obtained. Nothing approaching a quantitative separation of the substances could 

 be made. The crystals which were deposited were very characteristic, forming 

 six-pointed star-shaped crystals of the hexagonal system. They appeared to be 

 identical with those obtained by subliming a synthetic mixture of isoborneol and 

 terpineol. The crude isoborneol was recrystallized once from ligroin, but the 

 quantity obtained was not sufficient to permit of further purification. The crystals 

 melted at 198° to 204.° 



"■Joum.f. prakt. Ghem. (1894), (2) 49, 15. 



