Essential Oils of Australian Myrtaceae. 151 



The curve indicates; that the oil contains one preponderating 

 constituent, and suggests that this is probably pinene. 



Chemical Examination. 



« Pinene. — From a fraction boiling at about 156 deg. C. a nitro- 

 sochloride was prepared; melting point = 10-4-105 deg., indicating 

 presence of a-pinene. The rotation of the original oil and that 

 of the pinene fraction show that the hydrocarbon is present in the 

 dextro form, a conclusion in agreement with the observation that 

 the nitrosochloride was formed only with difficulty (v Gildemeister 

 ami Hoffmann— The Volatile Oils, p. 296). 



ft Pinene. — In order to test for the presence of ft pinene or 

 nopinene), which is associated with the n-pinene of turpentine oils, 

 the following experiment was carried out (Wallach, Liebs. Ann. 

 356. (1907), 228) :— 30 c.c. of a fraction boiling between 157 deg. 

 and 166 deg., was oxidised with excess of cold alkaline solution of 

 potassium permanganate, the liquor was filtered from manganese 

 dioxide, steam-distilled to remove unchanged oil, and concentrated 

 to a third of its original bulk. There was no separation of the 

 sparingly soluble sodium nopinate. (A control experiment using a 

 similar fraction from oil of turpentine yielded a sodium salt, the 

 acid set free from which had the melting point characteristic of 

 nopinic acid. ) 



Phellandrene. — The presence of phellandrene and other nitrosite- 

 forming hydrocarbons, was tested for with negative result. 



A c ids . — Absent . 



Esters. — The saponification number was 11.6, representing 4 per 

 cent, of esters, calculated as C 1 . 2 H 2n 0. 2 . In order further to 

 investigate the esters 100 c.c. of the original oil was saponified with 

 50 c.c of a 0.5 N. alcoholic solution of sodium hydroxide. After 

 saponification 60 c.c. of water was added to precipitate the oil; the 

 aqueous liquor was separated and evaporated to one-third of its 

 bulk, acidified with hydrochloric acid, and extracted with ether. 

 The ethereal extract was dried over calcium sulphate, and allowed 



