(R.T.B., Proc. Linn. Soc, N.S.W., 1899, p. 292, t. XX). White Top, Gully Ash, White Ironbark.

Systematic. - A tall tree, sometimes attaining a height of 150 feet, and a diameter from 2 to 5 feet. Bark of young trees has a strong resemblance to that of E. radiata, on old trees deeply furrowed, and in colour dark grey to blackish up to the branches, similar to that of the "Mountain Ash" (E. Sieber-iana, F.v.M.) or an "Ironbark," smooth to the branchlets. Abnormal leaves sessile, resembling chose of E. Amtraliana, E. phellandra, or E. radiata, lanceolate-cordate, 5 to 6 inches long, not glaucous. Normal leaves narrow-lanceolate, acuminate, of an equal colour on both sides, not shining; venation distinct and characteristic of cineol-pinene oil-yielding leaves, lateral veins fine, numerous, spreading, intramarginal vem slightly removed from the edge; petiole about 1 inch long. Oil-glands very numerous. Peduncles axillary, flattened, about as long as the petiole, with numerous flowers, from three to fifteen. Calyx turbinate, narrowing into a short pedicel, the whole 3 to 4 lines long; operculum hemispherical, shortly acuminate.

Fruit - Shortly pedicellate, hemispherical, inclining occasionally to pyriform; rim raised,-concave; valves well exserted and expanding, obtuse; 2 to 3 lines in diameter.

Care is required to differentiate it from E. viminalis, E. maculosa, and especially E. Gullicki, sp. nov. In some cases in the early and smaller fruits the rim is only slightly concave.

Habitat. - New South Wales Coast district, south from Mitta-gong, also Sugarloaf Mountain, Monga, and Irish Corner Mountain, Braidwood, Hill Top, Wingecaribbee, Sutton Forest, Nandi, extending into Victoria.

73 Eucalyptus Smithii 112

Plate XXXIII.

73 Eucalyptus Smithii 113

Eucalyptus Smithii, R.T.S. White Top or Gully Ash

REMARKS. - It attains a large size in suitable situations, and on the Nandi-road, Moss Vale, trees are found up to 14 feet in circumference, with bark exceedingly thick and deeply furrowed, strongly resembling in this feature that of some " Ironbarks " as E. crebra. In the medium and early stages of its growth the bark is somewhat smooth. The timber is pale-coloured, close-grained, hard, and difficult to work. It has been cut largely for works of construction in the Wingello district. In the field it is easy to confound it with E. Sieberiana on a cortical classification, and in the herbarium with E. Austruliana. the abnormal leaves having a great resemblance to that species, as they also do to E. rimtmtlis. The peculiar structure of its deeply furrowed bark distinguishes it from any of its congeners, particularly E. vinnnalis, Labill., which has not a thick, furrowed bark, traversed radially by broad rays of a yellow, pith-like substance, not possessing the characteristic odour so marked in this species.

Plate XXXIV.

73 Eucalyptus Smithii 114

[M. F. Connelly, Photo]

Eucalyptus Smithii. R T.B

"Gully Ash" Or "White Top."

Characteristic appearance of this Eucalypt as it grows in the gullies. Nearly the whole of the trees shown belong to this species. The figure at the base of the centre tree gives the comparative heights.

Wingello, N.S.W.

ESSENTIAL OIL. - Leaves and terminal branchlets for distillation were obtained from Sugar-loaf Mountain, Monga, near Braidwood, N.S.W., in September, 1898. The yield of oil was 1.4 per cent. The crude oil was light reddish yellow in colour, and had an odour resembling those of the cineol-pinene oils generally. Volatile aldehydes were present, but only in small amount, and the esters were also in a minimum quantity. The oil was exceedingly rich in cineol. Pinene was the principal terpene, and phellandrene was absent. Only a small amount of constituents having a high-boiling point (aromadendrene, etc.) was present, and 96 per cent. of the crude oil distilled below 1830 C, consequently the specific gravity was comparatively low for an oil so rich in cineol. The oil of this species is one of the best of the whole group for the distillation of a rich cineol bearing Eucalyptus oil. Crystallised eudesmol in small amount was present, although in that from the abnormal leaves it was difficult to detect. A solid paraffin was also present.

The crude oil had specific gravity at 150 C. = 0.915; rotation aD + 6.15°; refractive index at 200 C. = 1.4649, and was soluble in 1 1/4 volumes 70 per cent. alcohol. The saponification number for the esters and free acid was 2.4.

On rectification 1 per cent, distilled below 1680 C. (corr.). Between 168-1730, 64 per cent, distilled; between 173-1830, 31 per cent. distilled. These fractions gave the following results: -

First fraction, sp. gr. at 15o C.

=

0.911;

rotation aD

+

7.0o

Second

"

"

"

=

0.014;

"

+

4.14o.

The cineol, determined by the phosphoric acid method in the crude oil, was 70 per cent. (O.M.).

Material for distillation was also obtained from Irish Corner Mountain, Monga, N.S.W., in September, 1898. This second consignment was received in order to test the constancy of results as regards the oil of this species. The yield of oil was 1.6 per cent. The colour, odour, and constituents differed in no respect from those of the previous sample, and 96 per cent. distilled below 1830 C. By tabulating the results it is seen how closely the oils agree in general characters, the fractions and percentages being practically identical with each. Both oils were equally rich in cineol.

Specific Gravity at

15° C. Crude Oil.

Sparine

Gravity at

15° C. First

Fraction.

Specific

Gravity at

15°C. Second

Fraction.

Optical

Rotation Crude Oil

aD

Optical

Rotation

First Fraction

aD

Optical

Rotation

Sec. Friction

aD

E. Smithii, Monga, 5-9-88.

0.915

0.9110

0.914

+ 6.15°

+ 7.0°

+ 4.14°

E. Smithii, Monga, 28-9-88.

0.915

0.9107

0.913

+ 6.25°

+ 7.2°

+ 4.0°

Material of this species for distillation was also obtained from Wingello, N.S.W., in April, 1900. The yield of oil was 1.14 per cent. The oil differed in no respect from the previous samples, and was equally rich in cineol. The specific gravity of the crude oil was 0.9158, and the optical rotation aD + 4.9°. The amount of esters was also in agreement.

Since that time much oil from this species has been distilled commercially, and all the samples we have tested have shown great uniformity, and evidently the species is one that has long been stabilised.

Material for distillation was also obtained from the abnormal leaves in order to test the value of the oil from this portion of the plant; the leaves were collected at Wingello, N.S.W., in February, 1901. The yield of oil was 1.8 per cent. In appearance, odour, and constituents, the oil was identical with that obtained from the mature leaves, with the exception that the pinene was a little higher and the cineol a little less in amount; but even then the oil formed a clear solution with 1 1/4 volumes 70 per cent. alcohol. The specific gravity of the crude oil was 0.9133, and the optical rotation aD + 6.4°. The saponification number for the esters and free acid was 3. Eudesmol was detected in small amount. It is thus evident that the oil from the leaves of this species may be profitably distilled, especially as the yield is large for an oil so rich in cineol. In other parts of this work it is demonstrated that plantations of this species could be utilised with advantage for Eucalyptus oil distillation, so that by systematic cultivation the difficulty of collecting the leaves from mature trees might be avoided.

When the whole of the factors in regard to the oil of this species are taken into consideration, it may be regarded as one of the best Eucalypts, so far determined, for the production of a rich cineol Eucalyptus oil. The following reasons in support of this statement may be advanced: -

1. The yield of oil from both abnormal and mature leaves is large.

2. The oil from both abnormal and mature leaves is practically of equal value.

3. The oil is very rich in cineol.

4. A relative absence of constituents of high-boiling point avoids much loss on rectification.

5. The comparative absence of esters and objectionable volatile aldehydes allows the rectified oil to be of superior quality.

6. The species lends itself to ready cultivation.

See also the article on "The Variation in the character of Eucalyptus Oils distilled from trees of differing ages and forms of growth."