ELEMI. 187 



PlicUandrenc, G^QH-^^. (above referred to), was first discovered 

 in the essential oil of " Water Fennel," Phellanclriuin aqiudicum, of 

 which it forms the principal constituent. In much smaller 

 quantity it occurs also in ordinary Fennel oil from Fceniculum 

 officinale, together with ^^irwne and cUpentene, but anethol is the 

 principal constituent. 



In Elemi oil, phellandrene and dipentene constitute the main 

 components. The phellandrene in both Elemi and Fennel oils is 

 dextro-rotatory, whilst that found in Australian eucalyptus oils, 

 notably E. amygdalina, of which it forms the principal part, is 

 Isevo-rotatory. 



It also occurs in the oils of Curcuma longa, Piper nigrum, and 

 the oils of the root and seed of Angelica Archangelica. Possibly it 

 exists in other oils, the terpene constituents of which have not 

 been examined for it. Phellandrene and terpinene are characterized 

 by the formation of a crystalline nitrite, Cjo H-^^ ISTg 0^, when 

 acted upon by nitrous acid, a reaction which is not known to occur 

 with any of the other hydrocarbons, therefore phellandrene can be 

 very readily detected in admixture with the other terpenes by the 

 readiness with which its crystalline nitrosite is formed when a few 

 drops of a concentrated solution of sodium nitrite is added to a 

 glacial acetic acid solution of the terpenes, or to a ligroin solution 

 to which acetic acid is subsequently added. A white voluminous 

 mass of filmy crystals separates almost immediately, but although 

 phellandrene nitrosite is more C[uickly formed than the terpinene 

 compound, it is not nearly so stable, and can only be re- 

 crystallised with difficulty from a mixture of chloroform and 

 ligroin. AVhen pure the crystals melt at 102^ C, and have the 

 opposite rotatory power to the phellandrene from which they have 

 been prepared.* 



By the action of dry hydrochloric acid gas, Deville obtained from 

 his specimen of oil of Elemi a solid crystalline substance, C-^^ H-^^ 

 2 H CL, but Fllickiger failed to obtain from oil of Manilla elemi 

 any such compound ; and as further result of his researches, found 



* An elaborate study of the terpenes has been made by \Yallich, and 

 formed the subject of a lecture delivered before the Chemical Society at Berlin 

 in February 23, 1891, published in the Bericht., xxiv., p. 1525, and 

 abstracted into the London Pharm. Journ. [3], xxii., pp. 270, 350, 553 and 574, 

 1891. A summary of information on phellandrene and terpinene is also given 

 in " British and Colonial Druggist," xxii., p. 402. 



