(H.D. & J.H.M., Proc. Linn. Soc, N.S.W., 1900, p. 104, t. V.)

Systematic. - A tree of moderate size, attaining a height of 80 feet and a diameter of 2 feet 6 inches. The bark in appearance looks half "Ironbark" and half "Box," and has strong affinities to both. Abnormal leaves alternate, ovate, obtuse, slightly emarginate, and mucronate, about 3 inches long by 1 3/4 inch broad; intramarginal vein at a considerable distance from the edge. Normal leaves lanceolate, slightly falcate, pale-coloured, dull on both sides, rather coriaceous, usually 2 to 3 inches long; lateral veins at an angle of 30° with the mid-rib, but inconspicuous except the mid-rib and thickened margins, intramarginal vein indistinct and at some distance from the edge. Peduncles axillary, flattened at first, but nearly terete when the fruit is ripe, with three to seven flowers. Calyx tube attenuate, tapering into a short pedicel; the operculum attenuate.

Fruit. - Ovate-truncate, tapering at the base, somewhat contracted at the orifice; rim narrow, truncate, slightly convex and dark-coloured; valves depressed; about 3 lines in diameter.

Some of the fruits are uncommonly like those of E. albens, as also arc the buds.

Habitat. - Wellington and Dubbo, towards Molong and Parkes, Grenfell, and in other parts of the western districts of New South Wales.

REMARKS. - The true affinities of the species are in the opinion of Deane and Maiden (loc. cit.) with E.

sirferoxylon, A. Cnnn., and E.'. hemiphloia, F.v.M. Mr. Cambage is of opinion that the tree is a hybrid between E.

hemiphloia, or E. albens, and E. sideroxylon. Botanically it is close to E. albens, the thick, deeply furrowed bark being the only feature of differentiation. The timber of E. affinis varies, sometimes it is nearly as red as E. sideroxylon, sometimes much paler, approaching that of E. melliodora, and sometimes it is pale with red streaks or patches intermixed. In general aspect E. affinis is more like E. albens, and would never be mistaken for E melliodora or for E. hemiphloia. The result of our investigations shows it to have little connection with the group of "Boxes" to which E. albens or E. hemiphloia belong.

ESSENTIAL OIL. - Leaves and terminal branchlets for distillation were obtained from Grenfell, N.S.W., in April, 1901. The yield of oil was 0.26 per cent. The crude oil was of a reddish orange-brown colour, and had an odour resembling those belonging to the cineol-pinene class. Volatile aldehydes were not pronounced. Cineol was detected, but not in large amount. Pinene was present, but phellandrene was absent. The principal constituent in this oil was the sesquiterpene, and this, of course, caused the crude oil to have a high viscosity, a high specific gravity, and to boil at a high temperature. It is probable that aromadendral was present also, judging from the lævo-rotation of the second fraction and the odour.

The crude oil had specific gravity at 15° C. = 0.9259; rotation aD + 5.6°; refractive index at 200 C. = 1.4864, and was soluble in 1 volume 80 per cent, alcohol. The saponification number for the esters and free acid was 4.7.

On rectification, the usual amount of acid water and volatile aldehydes came over below 1650 C. (corr.). Between 165-1830, 39 per cent, distilled; between 183-2440, 17 per cent. came over, and between 244-2700, 35 per cent. distilled. These fractions gave the following results: -

The cineol, determined by the phosphoric acid method in the first fraction, was 29 per cent., or about 14 per cent, in the crude oil (O.M.)

This sample of oil had been kept in the dark, and in September, 1919, 18 years afterwards, was again analysed. Comparatively little alteration had taken place during that time, although the specific gravity had increased, and the rotation diminished a little. 42 per cent, distilled below 1900 C. The crude oil and the fraction below 190° gave the following results: -

The cineol, determined by the resorcinol method in the oil distilling below 1900, and calculated for the crude oil, was 28 per cent. By the phosphoric acid method it was 19 per cent.