URCEOLA ELASTICA: Shrubby, twining, leaves opposite, oblong, panicles terminal, is a native of Sumatra, Prince of Wales's Island, &c. Malay countries. Stem woody, climbing over trees, &c. to a very great extent, young shoots twining, and a little hairy, bark of the old woody parts thick, dark coloured, considerably uneven, a little scabrous, on which are found several species of moss, particularly large patches of lichen; the wood
is white, light, and porous. Leaves opposite, short-petioled, horizontal, ovate, oblong, pointed, entire, a little scabrous, with a few scattered white hairs on the under side. Stipulus none. Panicles terminal, brachiate, very ramus. Flowers numerous, minute, of a dull greenish colour, and hairy on the outside. Bracts lanceolate, one at each division and subdivision of the panicle. Galyx perianth, one-leaved, five-toothed, permanent. Corol one petalled, pitcher-shaped, hairy, mouth much contracted, five-toothed, divisions erect, acute, nectary entire, cylindric, embracing the lower two-thirds of the germa. Stamens, filaments five, very short from the base of the corol. Anthers arrow-shaped, converging, bearing their pollen in two grooves on the inside, near the apex; between these grooves and the insertions of the filaments they are covered with white soft hairs. Pistil, germs two; above the nectary they are very hairy round the margins of their truncated tops. Style single, shorter than the filaments. Stigma ovate, with a circular band, dividing it into two portions of different colours. Per. Follicles two, round, laterally compressed into the shape of a turnip, wrinkled, leathery, about three inches in their greatest diameters—one celled, two valved. Seeds very numerous, reniform, immersed in firm fleshy pulp.
See Plate XI.VII. where fig. 1. is a branchlet in flower of the natural size. 2. A flower magnified. 3. The same laid open, which exposes to view the situation of the stamens inserted into the bottom of the corol, the nectarium surrounding the lower half of the two germs, their upper half with hairy margins, the style and ovate party coloured; stigma appearing above the nectary. 4. Outside of one of the stamens; and, 5. Inside of the same, both much magnified. 6. The nectarium laid open, exposing to view the whole of the pistil. 7. The two seed vessels (called by Linnæus follicles), natural size; half of one of them is removed, to shew the seed immersed in pulp. A portion thereof is also cut away, which more clearly shews the situation and shape of the seed.
From wounds made in the bark of this plant there oozes a milky fluid, which on exposure to the open air separates into an elastic coagulum, and watery liquid, apparently of no use, after the separation takes place. This coagulum is not only like the American caoutchouc or Indian rubber, but possesses the same properties; for which, see CAOUTCHouc, both in the Encycl. and Suppl.
The chemical properties of this vegetable milk, while fresh, were found by Mr. Howison, late surgeon on Prince of Wales's Island, surprisingly to resemble those of animal milk. From its decomposition, in consequence of spontaneous fermentation, or by the addition of acids, a separation takes place between its caseous and ferous parts, both of which are very similar to those produced by the same process from animal milk. An oily or butyrous matter is also one of its component parts, which appears upon the surface of the gum so soon as the latter has attained its solid form. He endeavoured to form an extract of this milk so as to approach to the consistence of new butter, by which he hoped to retard its fermentative stage, without depriving it of its useful qualities; but as he had no apparatus for distilling, the surface of the milk, that was exposed to the air, instantly formed into a solid coat, by which
Urinary. which the evaporation was in a great degree prevented. Urtica. He, however, learned, by collecting the thickened milk from the inside of the coats, and depositing it in a jelly pot, that, if excluded from the air, it might be preserved in this state for a considerable length of time; and even without any preparation he kept it in bottles, tolerably good, upwards of twelve months.