(Labill., Voy. I, 403, t. 20, 1799.) Yate Gum.

Systematic. - A tree of moderate size with a smooth bark on the upper branches, but dark and rugged lower down, approaching that of an "Ironbark." Abnormal leaves orbicular or ovate. Normal leaves lanceolate, or ovate-lanceolate, thick, usually under 4 inches long; venation not prominent, intramarginal vein somewhat rernoved from the edge, lateral veins moderately oblique. Flowers six to twelve not immersed in the receptacle,' sessile on an axillary peduncle. Calyx tube oblong, turbinate; operculum about 1 1/4 inch long, tapering to the end, obtuse

Fruit. - Closely crowded in a cluster at the head of peduncle, bell-shaped, sessile or shortly pedicellate; rim narrow, surmounted by the valves, which connive and form a very conspicuous dome; 4 lines in length, exclusive of the much exserted valves.

At first appearance they show a resemblance to those of E. Lehmanni, but are quite separate and distinct from each other, and do not coalesce as in that species, nor are they immersed in the receptacle as obtains in E. Lehmanni. The two species have been confused by some systematists.

Habitat. - Western Australia.

ESSENTIAL OIL.-The oil of this species was distilled by Mr. P. R. H. St. John, at Melbourne, in September, 1919, from cultivated trees in the Botanic Gardens of that city. The yield of oil he obtained was 1.2 per cent. The crude oil was light in colour and contained a large proportion of volatile aldehydes, principally valeraldehyde. The constituents present were dextro-rotatory pinene, cineol, amyl alcohol, a butyric acid ester, higher boiling alcohols, and a little sesquiterpene. Phellandrene was absent.

The crude oil had specific gravity at 15o C. = 09043, rotation aD + 10.1°; refractive index at 20o = 1.4601, and was soluble in 2 volumes 70 per cent alcohol. The saponification number for the esters and free acid was 25.4, and in the cold with two hours' contact 14.8. After acetylation the number was 737. and in the cold 59. The indication is thus for a considerable amount of alcoholic bodies, but these are so mixed, that the molecular value cannot be stated. The aldehyde absorption was 8 per cent.

On rectification, no less than 8 1/2 per cent. distilled below 153° ('. (corr.). Between 153-171°, 18 per cent. distilled; between 171 193°. 63 per cent. came over, and between 191-214o, 8 per cent. These fractions gave the following results: -

The cineol was determined by the resorcinol method in the portion distilling between 153-193°; the result calculated for the original oil was 57 per cent. By the phosphoric acid method the cineol was 31 per cent., thus showing a large proportion absorbed by resorcinol other than cineol.

In the endeavour to locate these constituents a portion was separated, boiling between 151 - 192°; the amount which came over between those temperatures was 83 per cent. This fraction had specific gravity at 15° C. = 0.9033; rotation aD + 10.8°; refractive index at 20° = 1.4628. Saponification number 15.7, and in the cold with two hours' contact it was 13. After acetylating, the number was 42, thus showing that a considerable portion of the alcoholic bodies were high boiling. The cineol determined by the resorcinol method was 67.5 per cent.; and by the phosphoric acid method 40 per cent. by two determinations. The aldehydes by absorption were 6 per cent., and calculating for amyl alcohol, and butyl-butyrate as ester, a considerable portion of the absorbable bodies still remains unaccounted for, thus indicating the presence of an unreactive constituent which is also absorbed by resorcinol.