(J.H.M., in frit. Rev. Gen. Euc, 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 1 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 vertical; 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 lævo-rotatory pinene, phellandrene, cineol, and alcohols. Esters were not very pronounced.

The crude oil had specific gravity at 15° C. = 0.8982; rotation aD - 14.4°; refractive index at 200 = 1.4721, and was soluble in 1 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 C10H18O was thus 8 per cent.

On rectification, 1 per cent, distilled below 1660 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: -

The cineol, determined in the crude oil by the rapid phosphoric acid method, was 30 per cent.