- 6 5 - 



from its trihydrochloride, m. p. 79,3°. Tucholka was not quite clear 

 as to the particular class of terpenes to which his hydrocarbon belonged, 

 although its whole behaviour pointed to a sesquiterpene with three 

 double Unkings. Hence, Charabot, Dupont and Pillet, in their book 

 Les huiles essentielles as well as Schreiner in his monograph on Jhe Sesqui- 

 terpenes, class it without more ado among the sesquiterpenes. Burgess 

 and Page afterwards discovered in lime oil a sesquiterpene which they 

 called limene, and which also gave a tri-hydrochloride, melting at 79 

 to 8o°. Tucholka's work and the other literature referred to must 

 have been unknown to these two investigators, otherwise they would 

 certainly have compared the sesquiterpene of lime oil with bisabolene, 

 before endowing chemical literature with another new name 1 ). 



A fraction with a higher boiling point yielded a very minute 

 quantity of a hydrochloride, melting at 105 . After repeated recrys- 

 tallisation from alcohol its m. p. did not rise beyond no to 113 . 

 The behaviour of this body points to cadinene dihydrochloride. 



Our investigation therefore shows that, in addition to d-limonene, 

 which has long been known as the principal constituent, the only 

 body which occurs in the oil in relatively considerable proportions is 

 l-/?-pinene. Of 1- and i-a-pinene, 1-camphene, /J-phellandrene and 

 ^-terpinerie only small quantities were discovered; p-cymene could not 

 be detected at all. The sesquiterpenes only form a very inconsid- 

 erable proportion of the oil, which probably, besides bisabolene, also 

 contains cadinene. 



Orange Oils. We have lately examined in our laboratory some 

 orange oils produced in Jamaica; all of them had a good, intense 

 odour, and the samples which were pressed from sweet fruit also 

 agreed in their constants (apart from a slightly smaller residue of 

 evaporation) with Italian oils. The two samples of bitter oil on the 

 other hand were somewhat lighter, and showed a higher optical rotation 

 than is usually the case. Perhaps the cause of this lies in their source 

 of production. But as it is possible that the variations referred to 

 may be due to the addition of sweet to bitter oil, it is not out of 

 the question that insufficient care has been taken in selecting the fruit 

 for pressing. 



On the basis of numerous experiments with authentic oils we have 

 been able, several years ago, to trace clearly defined differences in 

 the constants of sweet and bitter orange oils of Italian origin. 2 ) The 

 following table clearly indicates the points in which Jamaica oils agree 

 with and differ from the Italian varieties: 



*) In the article which appears in the Wallach Jubilee - publication , further 

 details and a general compilation are given. 

 2 ) Report October 1906, 35. 



