Cultivation and Production[2198]—Cubebs are cultivated in small special plantations and also in coffee plantations, in the district of Banjoemas in the south of Java. The fruits are bought by Chinese who carry them to Batavia. They are likewise produced in Eastern Java and about Bantam and Soebang in the north-west; and extensively in the Lampong country in Sumatra. There has of late been a large distribution of plants among the European coffee planters.
The cultivation of cubebs is easy. In the coffee estates certain trees are required for shade: against these Piper Cubeba is planted, and climbing to a height of 18 to 20 feet, forms a large bush.
Description—The cubebs of commerce consist of the dry globose fruits, gathered when full-grown, but before they have arrived at maturity. The fruit is about ⅕ of an inch in diameter, when very young sessile, but subsequently elevated on a straight thin stalk, a little longer or even twice as long as itself. By this stalk the fruit is attached in considerable numbers (sometimes more than 50) to a common thickened stalk or rachis, about 1½ inch long.
Commercial cubebs are spherical, sometimes depressed at the base, very slightly pointed at the apex, strongly wrinkled by the shrinking of the fleshy pericarp; they are of a greyish-brown or blackish hue, frequently covered with an ashy-grey bloom. The stalk is the elongated base of the fruit, and remains permanently attached. The common axis or rachis, which is almost devoid of essential oil, is also frequently mixed with the drug.
The skin of the fruit covers a hard, smooth brown shell containing the seed, which latter when developed has a compressed spherical form, a smooth surface, and adheres to the pericarp only at the base; its apex either projects slightly or is pressed inwards. The albumen is solid, whitish, oily, and encloses a small embryo below the apex. In the cubebs of the shops, the seed is mostly undeveloped and shrunken, and the pericarp nearly empty.
Cubebs have a strong, aromatic, persistent taste, with some bitterness and acridity. Their smell is highly aromatic and by no means disagreeable.
Microscopic Structure—This exhibits some peculiarities. The skin of the fruit below the epidermis, is made up of small, cubic, thick-walled cells, forming an interrupted row, and only half as large as in black pepper. The broad middle layer consists of small cubic thick-walled cells, forming an interrupted row, and only half as large as in black pepper. The broad middle layer consists of small-celled undeveloped tissue containing drops of oil, granules of starch, and crystalline groups of cubebin, probably also fat. This middle layer is interrupted by very large oil-cells, which frequently enclose needle-shaped crystals of cubebin, united in concentric groups. The much narrower inner layer consists of about four rows of somewhat larger tangentially-extended soft cells, holding essential oil. Next to these comes the light yellow brittle shell, formed of a densely packed row of encrusted, radially-arranged, elongated thick-walled cells. Lastly, the embryo is covered with a thin brown membrane, and exhibits the structure and contents as that of Piper nigrum, excepting that in P. Cubeba the cells are rounder, and the crystals consist of cubebin and not of piperin.
Chemical Composition—The most obvious constituent of cubebs is the volatile oil, the proportion of which yielded by the drug varies from 4 to 13 per cent. The causes of this great variation may be found in the constitution of the drug itself, as well as in the alterability of the oil, and the fact that its prevailing constituents begin not to boil below 264° C. It is, as shown in 1875 by Oglialoro, a mixture of an oil C₁₀H₁₆, boiling at 158°-163°, which is present to a very small amount, and two oils of the formula C₁₃H₂₄, boiling at 262°-265° C. One of the latter deviates the plane of polarization strongly to the left, and yields the crystallized compound C₁₅H₂₄ 2 HCl, melting at 118° C. The other hydrocarbon is less lævogyrate and cannot be combined with HCl.
One part of oil of cubebs, diluted with about 20 parts of bisulphide of carbon, assumes at first a greenish, and afterwards a blue coloration, if one drop of a mixture of concentrated sulphuric and nitric acids (equal weight of each acid) is shaken with the solution.
The oil distilled from old cubebs on cooling at length deposits large, transparent, inodorous octohedra of camphor of cubebs, C₃₀H₄₈ + 2 OH₂, belonging to the rhombic system. They melt at 65° and may be sublimed at 148°. We have not succeeded in obtaining them by keeping the oil of fresh cubebs for two years in contact with water, to which a little alcohol and nitric acid was added.