243 



129. Eucalyptus Bancrofti. 



(J.H.M., in C'rit. Rev. (ion. Kur., vol. 4, 14, 1917.) 

 Rocky Gum. 



Systematic. A medium-sized tree, usually gnarled, bark smooth, falling 

 off in patches. Abnormal leaves ovate-lanceolate, on long, thin petioles. Normal 

 leaves lanceolate to ovate lanceolate, acuminate, sometimes falcate ; venation 

 seldom prominent, intramarginal vein fairly close to the edge, lateral veins inclined 

 at an angle of about 45 to mid-rib. Flowers up to seven in umbels, the common 

 peduncle about 4 lines long, axillary. Calyx tube short, about i to 2 lines long, 

 somewhat turbinate and contracting shortly to the pedicel ; operculum expanded 

 slightly above the top of the calyx tube, egg-shaped, about 3 lines long ; an outer 

 operculum first falls off, leaving a line of demarcation at its junction with the calyx 

 tube. 



Fruit. Hemispherical ; rim broad, almost ver- 

 tical ; valves prominent, much exserted ; 

 about 2 to 4 lines long and 3 lines in 

 diameter. 



These fruits are very similar to those of 

 E. Parramattensis, only larger. 



Habitat. Monaro to New England Tableland in the 

 interior, and Camden Haven to Grafton on 

 the Coast, New South Wales. 



ESSENTIAL OIL. Leaves and terminal branchlets for distillation were 

 collected at Tenterfield, N.S.W., in January, 1910. The yield of oil was 0-5 

 per cent. 



The crude oil was of an orange-brown colour, and had an odour indicating 

 a cineol-pinene oil, with a secondary one somewhat aromatic. The constituents 

 present were laevo-rotatory pinene, phellandrene, cineol, and alcohols. Esters 

 were not very pronounced. 



The crude oil had specific gravity at 15 C. = 0-8982 ; rotation a D - 14-4; 

 refractive index at 20 = 1-4721, and was soluble in i volume 80 per cent, alcohol. 

 The saponification number for the esters and free acid was 12-9 ; after acetylation 

 it was 41-6, and in the cold with two hours' contact 27-8; the free alcohol 

 calculated for C IO H j8 O was thus 8 per cent. 



On rectification, i per cent, distilled below 166 C. (corr.). Between 

 166-172, 10 per cent, distilled; between 172-178, 36 per cent, distilled ; between 

 178-193, 38 per cent, came over, and between 193-277, .12 per cent, distilled. 

 These fractions gave the following results : 



First fraction, sp. gr. at 15 C. := 0-8853; rotation D - - 15-8; refractive 



index at 20 = 1-4673. 

 Second ,, ,, ,, 0-8877; rotation a D - - 16-6; refractive 



index at 20 = 1-4685. 

 Third ,, ,, ,, = 0-8927; rotation a D - - 15-7; refractive 



index at 20 = 1-4699. 

 Fourth ,, ,, ,, = 0-9213; rotation a n - - 6-0; refractive 



index at 20 = 1-4870. 



The cineol, determined in the crude oil by the rapid phosphoric acid method, 

 was 30 per cent. 



