192 



PLATE LVII. 



The yield of oil obtained commercially varies according to the time of 

 year, and is also influenced by the amount of young leaf present. Statements 

 made by the distillers vary much, these ranging from 12 Ibs. of oil per 400 gallon 

 tank, to 30 Ibs. per tank. The yield is also largely governed by the way the leaf 

 is cut, if cut too coarsely the loss is in 

 two directions; (a) deficiency of leaf, 

 and (6) the springy nature of the 

 coarser stems preventing sufficient 

 loading in the tank. In a letter we 

 received from a correspondent who 

 gave his results for three months 

 (November, December, and January), 

 this is brought out clearly. Taking 

 the young leaf cut finely, the average 

 yield during that period was 65 Ibs. of 

 oil per ton of material ; but for old 

 leaves, coarsely cut, the average yield 

 was only 32 Ibs. per ton. This works 

 out at 2-9 per cent, for young leaf, 

 and 1-43 per cent, for old leaf, practi- 

 cally the same as we obtained in the 

 first investigation. Another distiller 

 informs us that his digesters hold 15 

 cwt. of material, and that he obtains 

 as an average 30 to 32 pounds of oil, or 

 1-8 to 1-9 per cent., but that at times 

 he has obtained up to 40 Ibs. 



It appears, therefore, that the yield of oil from old leaf of E. polybradea, 

 cut fairly, will be about 1-5 per cent., and from the young material about 2-5 per 

 cent. 



E. POLYBRACTEA, R.T.B. 

 " BLUE MALLEE." 



In this Plate the dense growth of this Mallee is shown. 



It will be seen that there is an absence of tall trees over 



the district. 



100. Eucalyptus cneorifolia. 



(DC., in Prod , iii, p. 220.) 

 Narrow-leaved Mallee. 



Systematic. A shrub or small tree. Leaves from narrow-linear to oblong- 

 lanceolate, straight or rarely falcate, mostly under 4 inches long, thick, with 

 fine diverging veins scarcely ever visible. Peduncles short, terete or scarcely 

 angular, each with a head of four to eight flowers, closely sessile or obscurely 

 pedicellate. Calyx 2 to 2| lines long, rather thick, but not angular ; operculum 

 hemispherical, much shorter than the calyx tube. 



Fruit. Pear-shaped or nearly globular, contracted 

 at the orifice ; rim rather thick, flat or 

 slightly convex ; the capsule more or less 

 sunk ; but the valves often slightly pro- 

 truding, about 3 lines in diameter. 



The resemblance in these fruits is nearest to E. 

 Wilkinsoniana, E. Banksia, E. Moorei, and occa- 

 sionally E cugenioides. 



Habitat. Kangaroo Island, South Australia. 



