The rhizome of Zingiber officinale (Amomum Zingiber), constitutes the ginger of commerce, which is imported chiefly from the East and West Indies. It is also grown in China. In the young state the rhizomes are fleshy and slightly aromatic, and they are then used as preserves, or prepared in syrup; in a more advanced stage the aroma is fully developed, their texture is more woody, and they become fit for ordinary ginger. The inferior sorts, when dried after immersion in hot water, form black ginger. The best roots are scraped, washed, and simply dried in the sun with care, and then they receive the name of white ginger. The rhizome contains an acid resin and volatile oil, starch and gum. It is used medicinally as a tonic and carminative, in the form of powder, syrup, and tincture.
The root stocks of Alpinia racemosa, A. Galanga, and many other plants of the order, have the same aromatic and pungent properties as ginger.
The consumption of ginger is about 13,000 or 14,000 cwt. a year. Of 16,004 cwt. imported in 1840, 5,381 came from the British West Indies, 9,727 from the East India Company's possessions and Ceylon, and 896 cwt. from Western Africa.
The difference between the black and white ginger of the shops is ascribed by Dr. P. Browne and others to different methods of curing the rhizomes; but this is scarcely sufficient to account for them, and I cannot help suspecting the existence of some difference in the plants themselves. That this really exists is proved by the statements of Rumphius ("Herb. Amb.," lib. 8, cap. xix., p. 156), that there are two varieties of the plant, the white and the red. Moreover Dr. Wright ("Lond. Med. Journal," vol. viii.) says that two sorts are cultivated in Jamaica, viz., the white and the black; and, he adds, "black ginger has the most numerous and largest roots."
The rhizome, called in commerce ginger root, occurs in flattish-branched or lobed palmate pieces, called races, which do not exceed four inches in length. Several varieties, distinguished by their color and place of growth, are met with. The finest is that brought from Jamaica. A great part of that found in the shops has been washed in whiting and water, under the pretence of preserving it from insects.
The dark colored kinds are frequently bleached with chloride of lime. Barbados ginger is in shorter flatter races, of a darker color, and covered with a corrugated epidermis. African ginger is in smallish races, which have been partially scraped, and are pale colored. East India ginger is unscraped; its races are dark ash colored externally, and are larger than those of the African ginger. Tellichery ginger is in large plump races, with a remarkable reddish tint externally.
Jamaica black ginger is not frequently found in the shops. The Malabar dark ginger is in unscraped short pieces, which have a horny appearance internally, and are of a dirty brown color both internally and externally.
Ginger is imported in bags weighing about a hundred-weight.
The Malabar ginger exported from Calicut is the produce of the district of Shernaad, situated in the south of Calicut; a place chiefly inhabited by Moplas, who look upon the ginger cultivation as a most valuable and profitable trade, which in fact it is. The soil of Shernaad is so very luxuriant, and so well suited for the cultivation of ginger, that it is reckoned the best, and in fact the only place in Malabar where ginger grows and thrives to perfection. Gravelly grounds are considered unfit; the same may be said of swampy ones, and whilst the former check the growth of the ginger, the latter tend in a great measure to rot the root; thus the only suitable kind of soil is that which, being red earth, is yet free from gravel, and the sod good and heavy. The cultivation generally commences about the middle of May, after the ground has undergone a thorough process of ploughing, harrowing, &c.
At the commencement of the monsoons, beds of ten or twelve feet long by three or four feet wide are formed, and in these beds small holes are dug at three-fourths to one foot apart, which are filled with manure. The roots, hitherto carefully buried under sheds, are dug out, the good ones picked from those which are affected by the moisture, or any other concomitant of a half-year's exclusion from the atmosphere, and the process of clipping them into suitable sizes for planting performed by cutting the ginger into pieces of an inch and a half to two inches long. These are then buried in the holes, which have been previously manured, and the whole of the beds are then covered with a good thick layer of green leaves, which, whilst they serve as manure, also contribute to keep the beds from unnecessary dampness, which might otherwise be occasioned by the heavy falls of rain during the months of June and July. Rain is essentially requisite for the growth of the ginger; it is also however necessary, that the beds be constantly kept from inundation, which, if not carefully attended to, the crop is entirely ruined; great precaution is therefore taken in forming drains between the beds, and letting water out, thus preventing a superfluity. On account of the great tendency some kinds of leaves have to breed worms and insects, strict care is observed in the choosing of them, and none but the particular kinds used in manuring ginger are taken in, lest the wrong ones might fetch in worms, which, if once in the beds, no remedy can be resorted to successfully to destroy them; thus they in a very short time ruin the crop. Worms bred from the leaves laid on the soil, though highly destructive, are not so pernicious to ginger cultivation as those which proceed from the effect of the soil. The former kind, whilst they destroy the beds in which they once appear, do not spread themselves to the other beds, be they ever so close, but the latter kind must of course be found in almost all the beds, as they do not proceed from accidental causes, but from the nature of the soil. In cases like these, the whole crop is oftentimes ruined, and the cultivators are thereby subjected to heavy losses.