8o 



THE TERPENES. When the cineol in the oil of the first two fractions was 

 combined with phosphoric acid in excess, the terpenes separated from the thick 

 jelly formed, and could be poured from the cineol phosphate. After agitating 

 with 50 per cent, solution of resorcinol, the separated liquid, after well washing 

 and drying, had specific gravity at 15 = 0-8641; rotation a D + 11-8; 

 refractive index at 20 = 1-4756. 



The oil was tinged yellow, had an odour resembling that of cymene, and 

 was very mobile. The terpenes were redistilled, when 50 per cent, came over 

 between 157-167 (corr.) and 34 per cent, between 167-172. These two frac- 

 tions gave the following results : 



First fraction, sp. gr. at 15 C. = 0-8604; rotation a v + 17-5, refractive 



index at 20 = 1-4715. 



Second ,, ,, : 0-8569; rotation a D + 9-1, refractive 



index at 20 = 1-4746. 



The nitrosochloride was readily formed with the first fraction, and this, 

 when purified, melted at 104 C. It was thus evident that the chief terpene in the 

 oil of this species was dextro-rotatory pinene. 



The specific gravity and refractive index suggested that the other terpene 

 was limonene or dipentene, and probably cymene was present also. The oil of this 

 species is thus shown to contain a predominance of terpenes, and to have little 

 value for commercial purposes. 



The results obtained with the oil of this species were published by us in 

 the Trans. Roy. Soc., South Australia, 1916. 



35. Eucalyptus rudis. 



(Endl., in Hueg. Enum., 49, 1837.) 



Systematic. A moderate-sized tree, the bark rough, and persistent. 

 Abnormal leaves ovate, petiolate; normal leaves lanceolate, often falcate, 

 acuminate, about 4 inches long, intramarginal vein not far removed from the 

 edge, lateral veins distant, inclined at about 45 to the mid-rib. Peduncles 

 axillary or lateral, about 6 lines long, bearing umbels of three to eight flowers. 

 Calyx tube turbinate, 3 lines long, tapering to a pedicql of equal length ; oper- 

 culum conoidal, often longer than the calyx tube. 



Fruit. Broad, turbinate or bell shaped, dilated at 

 the top, particularly so in the younger 

 stages ; rim truncate or very slightly 

 convex; valve's much exserted; 3 to 5 lines 

 long and 5 to 6 lines in diameter. 



E. patentinervis, an eastern species, more closely matches 

 this than any other, but is not quite so large. 



Habitat. Western Australia. 



ESSENTIAL OIL. Leaves and terminal branchlets for distillation were 

 forwarded by Mr. C. E. Lane-Poole, the Conservator of Forests, Western 

 Australia. The material was collected at Donnybrook, W.A., January, 1919, 

 The yield of oil was 1-2 per cent. 



