i8o 



ESSENTIAL OIL. During the months of May and June, 1897, a some- 

 what extensive investigation was undertaken on the oil of this species, and con- 

 siderable material distilled, which had been collected from individual trees 

 in various stages of growth. The results with the different samples of oil obtained 

 during that investigation will be found tabulated in a later article. The results 

 of this investigation were first submitted by us to the Royal Society of New South 

 Wales, and are published in the proceedings XXXI, p. 259. All the oils 

 contained similar constituents, and these only varied slightly in amounts, this 

 variation accounting for the slight differences in physical properties. With 

 general material even these slight alterations would be minimised and a closer 

 uniformity in general characters observed. The oil ol this species of Eucalyptus 

 was rich in cineol, contained pinene, but phellandrene was absent. Aromadendral 

 was present in small amount in the various samples, but was a little more 

 pronounced in some than in others. 



To arrive at the constitution and general character of the oil of this species, 

 equal volumes of the crude oils of all the samples were mixed together, and the 

 resulting product analysed. The mean yield of oil from all the material was 0-8 

 per cent. This crude mixed oil had specific gravity ati5C. = 0-9160; rotation 

 d D + 0-85; refractive index at 20 = 1-4717, and was soluble in i\ volumes 

 70 per cent, alcohol. The saponification number for the esters and free acid 

 was 18-8. 



On rectification i per cent, distilled below 167 C. (corr.). Between 167- 

 172, 30 per cent, distilled; between 172-183, 58 per cent, distilled. These 

 fractions gave the following results : 



First fraction, sp. gr. at 15 C. = 0-910; rotation a a + 2-15. 

 Second ,, ,, ,, = 0-9156; ,, + 1-1. 



The cineol, determined by the phosphoric acid method in the second 

 fraction, was 62 per cent., and in the crude oil 55 per cent. (O.M.). 



The rectified oil was slightly tinged yellow, a character usual with the 

 oils of this group, and is apparently due to the influence of the predominant 

 phenol present in these oils. 



The material from which the several. oils were distilled was collected from 

 (a) one fair-sized tree ; (b] one large tree ; (c) abnormal leaves ; (d) from a large 

 tree ; (e) from old trees mixed ; (/) from young trees 20-30 feet high, mixed ; 

 (g) from medium trees mixed ; () from one medium-sized tree ; (i) from one 

 very fine tree, the leaves of which were divided into two equal parts and 

 distilled separately. All the above material was collected near Sydney. 



The whole of the oils distilled for the above investigation were mixed 

 together, a portion kept in the dark, and in September, 1919, twenty-two years 

 afterwards, this oil was again analysed. It had not altered much during that 

 long period, except that the specific gravity was a little higher, but the cineol 

 apparently had not increased in amount. On rectification 82 per cent, distilled 

 below 190 C. The crude oil and large fraction gave the following results : 

 Crude oil, sp. gr. at 15 C. == 0-9337 ; rotation a D + 0-8 ; refractive index 



at 20 = 1-4724. 

 Large fraction ,, ,, =0-9147; rotation a D + i -6; refractive index 



at 20 = 1-4639. 



The cineol was determined by the resorcinol method in the large fraction 

 and calculated for the crude oil ; the amount was 65 per cent. By the rapid 

 phosphoric acid method it was 55 per cent., when calculated for the crude oil. 



