234 



ESSENTIAL OIL. Leaves and terminal branchlets for distillation were 

 forwarded by Mr. Walter Gill, the Conservator of Forests, South Australia. 

 The material was collected at the Parilla Forest Reserve, of that State, 

 in November, 1919. The yield of oil was 1-4 per cent. The crude oil 

 was of an orange-brown colour, and had an odour indicating those of the 

 " Mallee " oils, allied to the " Box " group. Aromadendral was quite pronounced. 

 The constituents present besides the aromadendral were dextro-rotatory pinene, 

 cymene, cineol, the sesquiterpene, and alcoholic bodies. Phellandrene was 

 absent. 



The crude oil had specific gravity at 15 C. = 0-9111 ; rotation a D 2-4; 

 refractive index at 20 = 1-4754, and was soluble in 5 volumes 70 per cent, alcohol. 

 The saponification number for the esters and free acid was 13-5 ; after acetylation, 

 it was 54-5, thus indicating n-6 per cent, of free alcohols having a C IO H l8 O 

 molecule. 



On rectification, i per cent, distilled below 160 C. (corr.). Between 

 160-172, 10 per cent, distilled; between 172-192, 71 per cent, came over, and 

 between 192-260, 18 per cent, distilled. These fractions gave the following 

 results : 



First fraction, sp. gr. at 15 C. = 0-8872; rotation a D + 3-5; refractive 



index at 20 = 1-4679. 

 Second ,, ,, ,, = 0-9023; rotation a D - 0-2; refractive 



index at 20 = 1-4719. 

 Third ,, ,, ,, = 0-9407; rotation a D - 10-8; refractive 



index at 20 = 1-4909. 



The cineol, determined by the resorcinol method in the portion distilling 

 below 192, and calculated for the original oil, was 40 per cent. By the rapid 

 phosphoric acid method it was 20 per cent., showing the presence of a considerable 

 amount of constituents, other than cineol, absorbed by the resorcinol. 



400 c.c. of the crude oil were distilled, and the portion which came over 

 below 188 C. (corr.") separated; this equalled 66 per cent. This portion had 

 specific gravity at 15 = 0-8976; rotation a D + 1-2; refractive index, 1-4706. The 

 saponification number for the esters and free acid was 9-2. After acetylation 

 this was 29, indicating 5-6 per cent, of alcoholic bodies with the C IO H I8 O 

 molecule. The aldehydic absorption was 5 per cent. 



The cineol in this large portion, determined by the resorcinol method, 

 was 45 per cent., and by the phosphoric acid method 35 per cent. This result 

 indicates that bodies other than cineol were absorbed by the resorcinol. No less 

 than ii per cent, distilled between 188-192, which portion was evidently largely 

 absorbed. 



The aromadendral was separated by acid sodium sulphite from the portion 

 boiling above 188; when purified it had optical rotation a D -- 49-8. 



The cymene was determined in the portion distilling below 188 C. The 

 cineol was removed by phosphoric acid, and 50 per cent, resorcinol. The 

 remaining oil was distilled, and the required fraction separated. This had specific 

 gravity at 15 C. -- 0-8642; rotation, nil, and refractive index at 20 - 1-4845. A 

 portion was oxidised by potassium permanganate in the usual way. The 

 finally prepared acid melted at 155-156 C., thus indicating p-oxyisopropyl- 

 benzoic acid, the oxidation product of p-cymene. 



