- 38 - 



3O°/ 1 ) Clover collected 21 different samples elemi, and distilled them 

 separately. The oils thus obtained showed considerable differences in 

 the constants and composition, and were classified as follows: - 



1. The oils 1 to 10 consisted of pure d-limonene. 



2 . Oils 11 to 19 contained a greater or smaller proportion of 

 phellandrene; of these, oils 11 to 13 had a peculiar odour which 

 could not be defined, and the boiling point observed at the com- 

 mencement of the distillation was in these oils lower than in the 

 remaining six oils of this group. According to this, there appears 

 also to be present in the three oils a lower boiling terpene, probably 

 pinene or an allied terpene. Of the remaining six oils containing 

 phellandrene, one was laevorotatory, the other five more or less 

 strongly dextrorotatory. Of the latter, the two oils with the highest 

 dextrorotation had also a somewhat higher boiling point, whilst the 

 three other oils appeared to consist of pure phellandrene. The 

 laevorotatory oil contained chiefly 1-limonene. 



3. Oils 20 and 21, both rotating -|- 4 to the right, consisted 

 of almost pure terpinene and terpinolene respectively. 



The presence of terpinolene had hitherto not been observed in 

 nature, and is therefore remarkable, the more so, as the oil containing 

 terpinolene showed a very peculiar behaviour. The crude oil already 

 boiled within one degree (Clover does not mention the boiling point), 

 and had a rotation of -|- 4 . The reactions for terpinene and 

 phellandrene had negative results; but a bromide of the m. p. 116 

 to 1 1 7 (with brown coloration and foaming) could be obtained in 

 the form of brilliant scales (from alcohol). From this the presence of 

 terpinolene might be assumed, whose boiling point Wallach determ- 

 ined at 185 to 190 , v. Baeyer (in a preparation regenerated from 

 the tetrabromide) at 183 to 185 . The oil containing terpinolene 

 was once more purified by treatment with potassium hydrate, distilled 

 in vacuo, and had then the constants: d-^ 0,8360; «D3o° -}- Ij7°; 



n D30° l A7° l ) b. p. 173,5 to x 75° ( at ordinary pressure); 80 to 8i° 

 (37 mm. pressure). Strange to say, the rotation had decreased con- 

 siderably between the second and third distillation, although the 

 oil had been prepared only on the previous day from elemi. In 

 order to accelerate a possible change in the principal constituent of 

 the oil, a portion of it was heated for 3 hours in a sealed .tube 

 on an oil bath to 200°. The distillate now showed a rotation of 

 — 7,5°, and gave a not very powerful phellandrene-reaction 

 (nitrite, laevorotatory, m. p. 119 to 120 ). Five days later it was 

 again intended to produce terpinolene tetrabromide from the purified 

 oil, but instead of this there were obtained crystals of the m. p. 120 



1 ) Gildemeister and Hoffmann, The Volatile Oils, p. 491. 



