179 



The above samples were mixed together, stored in the dark, and in 

 September, 1919, the oil was again analysed. The specific gravity had increased 

 somewhat during the 20 years it had been kept, and the cineol had also increased 

 in amount. This is well shown by the constants obtained with the rectified oil. 

 The crude oil and the rectified portion gave the following results. 84 per cent, 

 distilled below 190 C. : 



Crude oil, sp. gr. at 15 C. ;; 0-9518; rotation a + 4-9; refractive 



index at 20 1-4667. 

 Rectified portion ,, ,, = 0-9267; rotation a D + 3-0; refractive 



index at 20 = 1-4596. 



The cineoj was determined by the resorcinol method in the rectified portion 

 and calculated for the crude oil ; the result was 79 per cent. By the rapid 

 phosphoric acid method it was 66 per cent., when calculated for the crude oil. 

 Terpineol was detected in 'he rectified portion. 



We have described somewhat fully the various samples of oil obtained 

 from this species,, as the localities enumerated cover a large area, and the time 

 extends over some years. The results show how closely related are the chemical 

 constituents of the products of a particular species of Eucalyptus, irrespective 

 of location or environment. 



93. Eucalyptus punctata. 



(DC., Prod., iii, 217.) 

 Grey Gum. 



Systematic. A large tree, with a dirty looking, smoothish, or friable 'bark, 

 and rectangular branchlets. Abnormal leaves ovate, lanceolate, often shortly 

 acuminate, 4 to 6 inches long, pale coloured on the underside, sometimes almost 

 oblique, membraneous, margins recurved ; venation distinct, oblique, spreading. 

 Normal leaves lanceolate, sometimes oblique, pale on the underside, varying 

 in length and breadth up to 6 inches and 2 inches respectively, chinly 

 coriaceous; venation not pronounced, lateral veins fine, oblique, parallel, intra- 

 marginal vein close to the edge. Peduncles axillary, flattened, under 6 lines long, 

 about six flowers in the umbel. Calyx in the bud stage angular, conical ; in the 

 flower stage hemispherical; operculum conical or hemispherical, and much 

 acuminate, under 3 lines long. 



Fruit. Turbinate to hemispherical, pedicel thick, 

 short ; rim thick, domed ; valves obtuse, 

 well exserted and pale ; 4 lines in diameter. 



They are quite specific; the dark slightly domed rim 

 is the more common and easily distinguished, but 

 occasionally the rim is truncate, giving the capsule an 

 E. resinifera appearance. 



Habitat. Coast districts of New South Wales and Queens- 

 land. 



REMARKS. This is one of the best-known trees in the neighbourhood of Sydney, where its common 

 appellation is " Grey Gum." The bark is characteristic, and although classed as smooth, yet is perhaps the dirtiest 

 looking bark to be found amongst the smooth-barks or Gums, in the older trees it becomes dark, rugose, variegated, 

 and exudes manna (H. G. Smith; see Paper in Proc. Roy. Soc., N.S.W., Vol. 31, p. 177), as well as the leaves. The 

 mountain varieties are separated under the varietal names of didyma and major. 



