(F.v.M., in B.F1., iii, 207.) Red Stringybark.

Systematic. - A tall tree, bark compact, coarse, stringy, blackish on the outer surface. Abnormal leaves ovate to lanceolate, falcate, shortly acuminate, about 6 inches long and 2 inches broad; venation well marked, lateral veins few, spreading, intramarginal vein removed from the edge. Normal leaves oblique, lanceolate, or ovate-lanceolate, generally under 6 inches long, slightly shining; venation distinct, lateral veins oblique, few, spreading, in the broader leaves the intramarginal vein is well removed from the edge. Peduncles axillary, up to 1 inch long, flattened, bearing about half-a-dozen flowers. Calyx tube angular, often 6 lines long, including the pedicel; operculum of two forms: (a) conical, with a sharp constriction above the calyx rim, 3 lines long; (b) hemispherical, shortly acuminate, about 2 lines long.

Fruit. - Shortly pedicellate, hemispherical, to pear-shaped, slightly ribbed; rim strongly domed; valves sharp-pointed and well exserted; up to 6 lines in diameter.

The fruit of E. macrorhyncha is so characteristic that the species is very rarely, if ever, confounded with any other Eucalyptus, and it can easily be identified from the accompanying plate. The large fruited form figured in the 1st Edition has since been raised to specific-rank under the name of E. Cannoni.

Habitat. - Rylstone district, Bungendore to Victorian boundary, Barber's Creek, New South Wales; and all the Eastern States.

REMARKS. - Our researches show that this species is superior to most of its congeners in the number of its economics. In addition to its timber and bark it yields (1) eudesmol, (2) an oil occasionally containing 50 per cent, of cineol, and (3) the khaki yellow dye, myrticolorin. It is called "Red Stringybark" in allusion to the colour of its timber, as compared to that of other "Stringybarks," such as E. eugenioides, Sieb., E. capitellata, Sm., and E. lævopinea, R.T.B.

ESSENTIAL OIL. - Leaves and terminal branchlets for distillation were obtained from the Rylstone District, N.S.W., at various times during March, 1898, from which nine separate distillations were made. The oils of all these samples were in agreement, and the yields averaged 0.29 per cent. The crude oil was reddish-brown in colour, and had an odour resembling those belonging to the cineol-phellandrene group. A small quantity of pinene occurs in the oil of this species, and phellandrene was present also, occurring in greatest amount during the early spring months. Cineol was present in some quantity at certain times of the year. Eudesmol was often a pronounced constituent, and it was from the oil of this species that this stearoptene was first obtained in sufficient amount for investigation. The sesquiterpene was pronounced in the higher-boiling portion.

The mixed crude oils of all the samples had specific gravity at 150 C. = 0.929; refractive index at 200 = 1.4745, and was soluble in 2 volumes 70 per cent, alcohol. The saponification number for the esters and free acid was 8-4.

On rectification, 2 per cent. distilled below 1720 C. (corr.). Between 172-176°, 23 per cent, distilled; between 176-186°, 32 per cent, came over; between 186-268°, 11 per cent, distilled, and between 268-289°, 27 per cent, distilled. These fractions gave the following results: -

The cineol, determined by the phosphoric acid method in the oil distilling below 186°, was 52 per cent., indicating about 30 per cent, in the crude oil (O.M.).

Myrticolorin. - The leaves of E. macrorhyncha contain a large amount of a yellow dye material, discovered by one of us in 1897. (Proc. Roy. Soc, N.S.W.) It was there named Myrticolorin. Its chemistry was afterwards described in a paper (Journ. Chem. Soc, 1898, p. 697). It is a glucoside of quercetin, having the formula C27H30Ol6 and on hydrolysis breaks down into quercetin, glucose, and rhamnose by the following reaction: - C27H30Ol6 + 3 H2O = CI5H10O7 + C6HI2O6 + QHI4O6.

Osyritrin, Viola-quercetin and Rutin, are analogous substances. Myrticolorin gives colours, when mordanted, resembling those obtained similarly with the better qualities of flavin, and decidedly purer than those given by quercitron bark itself, or with fustic. The colours are quite fast to light and to milling. The extraction of myrticolorin from the leaves of this Eucalyptus is exceedingly simple, but it is important that the leaves be ground to a very fine powder. When the powdered leaves are boiled and filtered boiling hot, the myrticolorin passes with the filtrate, but crystallises out again on cooling, as it is very slightly soluble in cold water. The tannins and other bodies extracted at the same time remain in solution, and can be removed by filtration; the myrticolorin can then be washed with cold water, pressed, dried, and powdered. A determination, on a semi-commercial scale, gave at the rate of 8 1/2 lbs. of dried myrticolorin from 100 lbs. of powdered leaves, collected as would be done for commercial oil distillation. Eucalyptus macrorhyncha is a common tree in New South Wales and Victoria, so that there is an abundance of material available.

The presence of this dye material in the leaves of E. macrorhyncha at once distinguishes it from E. lævopinea, and is another illustration of the value of chemical evidence in determining differences between Eucalyptus species closely allied morphologically. Traces of this dye have been detected in the leaves of other species, but, so far, the amount has not been determined. It may be found eventually, however, that E. macrorhyncha does not give the maximum yield of this dye material, particularly as the leaves of some species become quite yellow when dry.