(H.D. & J.H.M., Proc. Linn. Soc, N.S.W., 1897, p. 561, t. XIX.)

Ironwood

Systematic. - A fair sized tree, with a scaly or smoothish bark, somewhat resembling that of E. punctata. Abnormal leaves ovate, and finally ovate-lanceolate. Normal leaves narrow to rather broad-lanceolate, or ovate-lanceolate, slightly falcate, 3 1/2 to nearly 6 inches long, pale green to glaucous, the surface glandular punctate; intramarginal vein very near the edge, transverse veins numerous and fine. Peduncles roundish, not flattened, nor angular, frequently or usually in pairs. The flowers generally from eight to twelve in the umbel. Calyx tube sub-cylindrical, almost ovate, somewhat urceolate in young fruit; operculum ovate, but more or less pointed or beaked, and frequently showing a marked curve to one side. The length of the operculum about equal to that of the calyx, viz., about 3 lines.

Fruit. - Nearly hemispherical, with a slight tendency to constriction at the orifice; rim inclined to be countersunk; valves 3 or 4 and slightly exserted; about 4 lines broad by 3 lines long.

Although there is nothing particularly characteristic about the fruit yet when once known it is not easily mistaken for any other.

Habitat. - On sterile sandstone ridges in the county of Cumberland, National Park, Putty, Kelgoola, near Rylstone, St. Marys, New South Wales.

REMARKS. - Its most obvious characteristic is its scaly bark. Another good characteristic of the species is the curved operculum of the buds, which seems to obtain wherever the species occurs.

ESSENTIAL OIL. - Leaves and branchlets for distillation were obtained from National Park, near Sydney, N.S.W., in September, 1900. The yield of oil was 0.65 per cent. The oil was but slightly coloured, and had an odour resembling those of the cineol-pinene group. Volatile aldehydes were present in some quantity. It contained much cineol, some pinene, and a trace of phellandrene, although at other times this constituent appeared to be absent. A small quantity of aromadendral was detected, and consequently the second fraction had a slight lævo-rotation.

The crude oil had specific gravity at 150 C. = 0.9182; rotation nil; refractive index at 200 = 1.4635, and was soluble in 1 1/4 volumes 70 per cent. alcohol. The saponification number for the esters and free acid was 5.5.

On rectification 2 per cent. distilled below 167°C. (corr.). Between 167-1830, 80 per cent. distilled, and between 183-2470, 10 per cent came over.

The-large fraction had specific gravity at 150 = 0.9161; rotation aD + 0.8°. The second fraction had specific gravity at 150 = 0.9278; rotation not taken. The cineol, determined in the large fraction by the phosphoric acid method, was 60 per cent., indicating about 51 per cent. in the crude oil (O.M.).

In the year 1900 this species was worked commercially for its oil at Nelson, near Riverstone, N.S.W. The oil obtained was practically identical with the above, and the crude oil contained 61 per cent, of cineol determined by the phosphoric acid method (O.M.).

Another sample distilled at the end of the year 1900 also gave similar results.

The above oils were mixed together and preserved in the dark, and in September, 1919, nineteen years afterwards, this oil was again analysed. Not much alteration was observed, except that it was a little heavier and contained more cineol. 90 per cent, distilled below 1900. The crude oil and the large fraction gave the following results: -

The cineol was determined by the resorcinol method in the large fraction, and calculated for the crude oil; the result was 81 per cent. By the rapid phosphoric acid method it was 70 per cent., when calculated for the original oil.