213 



The cineol was determined by the resorcinol method in the first fraction ; 

 when calculated for the crude oil the result was n per cent. 



For the determination and identification of the low-boiling constituents 

 in the oil of this species another portion was distilled. The oil which came over 

 below 185 C. was added to that of the first distillation, and the whole refractionated, 

 using a rod and disc stillhead. Although commencing to distil at 157, yet only 

 7 per cent, came over below 170 C. (corr.); but at 173, 38 per cent, had distilled. 

 The three fractions were separated as follows : 157-173, 38 per cent. ; 173-175, 

 31 per cent. ; 175-179, 15 per cent. ; residue boiling above 179, 16 per cent. 

 The fractions anil residue gave the following results : 



First fraction, sp. gr. at 15 C. ;; 0-8647; rotation a D - - 4-5; refractive 



index at 20 = 1-4777. 

 Second ,, ,, ,, = 0-8676; rotation a D - - 6-4; refractive 



index at 20 = 1-4806. 

 Third ,, ,, ,, : 0-8714; rotation a D - - 7-2; refractive 



index at 20 = 1-4812. 

 Residue ,, ,, : 0-9063; rotation a -- 17-8 ; refractive 



index at 20 = 1-4880. 



It was thus evident that the amount of pinene could be but small, and that 

 it was either inactive or slightly laevo-rotatory. The high refractive index, and 

 low specific gravity, suggests the presence of cymene. Phellandrene was detected 

 in oil three fractions. 



Cineol was also detected in all three fractions, and as this constituent was 

 small in amount it was removed by agitating each fraction with 50 per cent, 

 resorcinol, and the uncombined portions washed and dried. The influence of 

 the cineol is shown from the following figures, when compared with those given 

 above : 



First fraction, sp. gr. at 15 C = 0-8613; refractive index at 20 = 1-4805. 

 Second ,, ,, ,, = 0-8649; refractive index at 20 = 1-4842. 



Third ,, ,, ; 0-8667; refractive index at 20 = 1-4856. 



Cymene. The determination of the results as recorded above suggested 

 the presence of cymene, and to arrive at the identity of this hydrocarbon, the 

 fraction of the rectified oil, thought to contain cymene in greatest quantity, was 

 oxidised by an aqueous solution of potassium permanganate (12 grams KMnO 4 

 in 330 grams water), as suggested by Wallach ; about 2 grams of oil at the time 

 were added, and the solution heated on a rapidly boiling water-bath. When the 

 reaction was completed the precipitate was filtered off, the filtrate evaporated 

 to dryness, the salt boiled out by alcohol, evaporated to small bulk, water added 

 and acidified with sulphuric acid. The separated acid was purified from alcohol ; 

 it then melted at 155-156 C. From the method of formation, and its melting 

 point, there seems little doubt but that the acid formed was p-oxyisopropylbenzoic 

 acid. This result, together with other factors, indicates the presence of p-cymene 

 in some quantity in the oil of E. rostrata. 



It will thus be seen that this oil differs entirely from that derived from 

 its variety borealis. 



(For the determination of the aromadendral see the article in this work 

 on " The cyclic (aromatic) aldehydes occurring in Eucalyptus oils.") 



