(R.T.B. & H.G.S., Roy. Soc, Tas., 1912, p. 191, t. II.) Apple-Scented or Black Gum.

Systematic. - A large forest tree; often 4 feet in diameter. Bark persistent on stem and branches. Abnormal leaves alternate, oval lanceolate to ovate lanceolate, 3 inches long and about 1/2 inch broad, inclined to falcate, petiolate, almost membraneous; venation not pronounced, lateral veins distinctly oblique at the base and less so towards the apex. Normal leaves lanceolate, sometimes falcate, up to 6 inches long, but usually under 4 inches, and \ inch wide, thicker than abnormal leaves; venation not prominent, intramarginal vein slightly removed from the edge. Peduncles axillary or lateral, about 3 lines long, usually bearing under six flowers. Calyx tube about 2 lines, shortly pedicellate,- operculum conical, acuminate.

Fruit. - Conical or hemispherical, to slightly pyriform; rim convex, sometimes cracked transversely; valves slightly exserted; under 2 lines long and 2 lines in diameter.

These so resemble those of E. Macarthuri and E. aggregata that without taking into account other physical characters all these species may easily be confounded.

Habitat. - Deloraine (Maiden and Cambage). Between Inter laken and Tunbfidge, at an elevation of 3,000 feet and down the western slopes to quite a low altitude; also Strickland, Tasmania (L. G. Irby)

REMARKS. - A species endemic to Tasmania, with specific characters distinct from any of the mainland Eucalypts, although Maiden synonymised it in Roy. Soc. Tas., 1914, p. 30, under E. aggregata, D. & M., but our results for this species do not agree with the physical and chemical properties described under that species, any more than they do when it was considered to be E. Macarthuri.

ESSENTIAL OIL. - Material of this species for distillation was collected at Deloraine, Tasmania, in June, 1912. The crude oil when cleared was light olive-brown in colour, and had a terpene-like odour, together with that of cineol, but with no resemblance to geranyl-acetate. It contained pinene as the chief terpene, and phellandrene could not be detected. It was rich in cineol, over 60 per cent, of the crude oil being that constituent. The saponification number for the esters and free acid was only 3.96, representing 1.38 per cent. of ester if calculated as geranyl-acetate. The amount of ester in the oil of this species is thus low. The yield of oil was 0.48 per cent., too small an amount to render the oil of commercial value.

The crude oil had specific gravity at 15° C. = 0.9075; rotation aD + 10.6°; refractive index at 200 = 1.4671; and was soluble in 6 volumes 70 per cent, alcohol.

On rectification, the usual amount of acid water and volatile aldehydes were obtained below 1640 C. (corr.), at which temperature the oil commenced to distil. Between 164-1730, 33 per cent, distilled; between 173-1980, 57 per cent, came over, and between 198-265°, 5 per cent, distilled. The high-boiling fraction contained a constituent with rotation to the right, but it was not isolated. It was apparently the liquid form of eudesmol. The following results were obtained with the several fractions: -

The cineol, determined by the resorcinol method in the oil distilling below 198° C, and calculated for the crude oil, was 64 per cent. By the rapid phosphoric acid method the result was 50 per cent., when calculated for the crude oil. After acetylation the saponification number was 24.5, thus showing the presence of bodies, other than alcohols, absorbable by resorcinol. The rectified oil had a yellowish tinge, a peculiarity often found with the cineol-pinene oils distilled from the leaves of the smooth bark "Gums" like E. globulus, E. goniocalyx, etc. Pinene was isolated from the first fraction, and proved to be that substance by the formation of the nitrosochloride, which melted at the correct temperature for that substance.

This species has no close connection with E. Macarthuri of New South Wales, as the oil of that species appears never to contain less than 60 per cent, of geranyl-acetate at any time of the year, the ester often rising to 75 per cent., and one determination of the oil from the abnormal leaves showed that it contained over 77 per cent, of geranyl-acetate. Cineol does not appear to occur in the oil of E. Macarthuri, although pinene is usually present in small amount.

The results of this investigation were published by us in the Proc. Roy. Soc, Tasmania, October, 1912.

Plate XXVI.

R.T.B., del.

Eucalyptus Cinerea, F.v.M. Argyle Apple