part 9

. (1876).

[2367] Flückiger, _Die Frankfurter Liste_, Halle, 1873. 11.

[2368] Raine, _Wills and Inventories of the Archdeaconry of Richmond_ (Surtees Society), 1853. 277.

=Description=—The base of the scrape thickens in the first year into an ovate rootstock; this afterwards throws out shoots, forming lateral or secondary rhizomes, each emitting roots, which branch into fibres or are sometimes enlarged as colourless spindle-shaped tubers, rich in starch. The lateral rhizomes are doubtless in a condition to develope themselves as independent plants when separated from the parent. The central rhizomes formerly known as _Curcuma rotunda_, and the elongated lateral ones as _Curcuma longa_, were regarded by Linnæus as the production of distinct species.

The radical tubers of some species of _Curcuma_, as _C. angustifolia_ Roxb., are used for making a sort of arrowroot (p. 637). Sometimes they are dried, and constitute the peculiar kind of turmeric which the Chinese call _Yuh-kin_.[2369]

The turmeric of commerce consists of the two sorts of rhizome just mentioned, namely, the _central_ or _round_ and the _lateral_ or _long_. The former are ovate, pyriform or subspherical, sometimes pointed at the upper end and crowned with the remains of leaves, while the sides are beset with those of roots and marked with concentric ridges. The diameter is very variable, but is seldom less than ¾ of an inch, and is frequently much more. They are often cut and usually scalded in order to destroy their vitality and facilitate drying.

The lateral rhizomes are subcylindrical, attenuated towards either end, generally curved, covered with a rugose skin, and marked more or less plainly with transverse rings. Sometimes one, two or more short knobs or shoots grow out on one side. The rhizomes, whether round or long, are very hard and firm, exhibiting when broken a dull, waxy, resinous surface, of an orange or orange-brown hue, more or less brilliant. They have a peculiar aromatic odour and taste.

Several varieties of turmeric distinguished by the names of the countries or districts in which they are produced, are found in the English market: but although they present differences which are sufficiently appreciable to the eye of the experienced dealer, the characters of each sort are scarcely so marked or so constant as to be recognizable by mere verbal description. The principal sorts now in commerce are known as _China_, _Madras_, _Bengal_, _Java_, and _Cochin_. Of these the first-named is the most esteemed, but it is seldom to be met with in the European market.[2370]

_Madras Turmeric_ is a fine sort in large, bold pieces. Sometimes packages of it contain exclusively round rhizomes, while others are made up entirely of the long or lateral.

_Bengal Turmeric_ differs from the other varieties chiefly in its deeper tint, and hence is the sort preferred for dyeing purposes.

_Java Turmeric_ presents no very distinctive features; it is dusted with its own powder, and does not show when broken a very brilliant colour. Judging by the low price at which it is quoted it is not in great esteem. It is the produce of _Curcuma longa_ var. β. _minor_[2371] Hassk.

[2369] Hanbury, _Pharm. Journ._ iii. (1862) 206; also _Science Papers_, 254, fig. 11.—It is not wholly devoid of yellow colouring matter.

[2370] A good deal is exported from Takow in Formosa, but mostly to Chinese ports.—_Returns of Trade at the Treaty Ports of China for 1872._ p. 106.

[2371] From information communicated by Mr. Binnendyk, of the Botanical Garden, Buitenzorg, Java.

=Microscopic Structure=—The suberous coat is made up of 8 to 10 rows of tabular cells; the parenchyme of the middle cortical layer of large roundish polyhedral cells. Towards the centre the transverse section exhibits a coherent ring of fibro-vascular bundles representing a kind of medullary sheath. The parenchyme enclosed by this ring is traversed by scattered bundles of vessels, and in most of its cells contains starch in amorphous, angular, or roundish masses, which are so far disorganized that they no longer exhibit the usual appearance in polarized light, but are nevertheless turned blue by iodine. The starch has been reduced to this condition by scalding.

Resin likewise occurs in separate cells, forming dark yellowish-red

## particles. The entire tissue is penetrated with yellow colouring

matter, and shows numerous drops of essential oil, which in the fresh rhizome is no doubt contained in peculiar cells.

=Chemical Composition=—The drug yielded us (1876) one per cent. of a yellow essential oil, which contains a portion boiling at 250° C., answering to the formula C₁₀H₁₄O; this liquid differs from carvol (p. 306) by being unable to combine with SH₂. The other constituents of curcuma oil boil at temperatures much above 250°; we found the crude oil and its different portions slightly dextrogyrate.

The aqueous extract of the drug tastes bitter, and is precipitated by tannic acid.

The colouring matter, _Curcumin_, C₁₀H₁₁₀O₃, may be obtained to the amount of ⅓ per cent. by depriving first the drug of fat and essential oil. The powder, after that treatment with bisulphide of carbon, is gradually exhausted, according to Daube (1871), with warm petroleum (boiling point 80°-90° C.). On cooling chiefly the last portions of petroleum deposit the crystalline curcumin. Its alcoholic solution is purified by mixing it cautiously with basic acetate of lead, not allowing the liquid to assume a decidedly acid reaction. The red precipitate thus formed is collected, washed with alcohol, immersed in water, and decomposed with sulphuretted hydrogen. From the dried mixture of sulphide of lead and curcumin the latter is lastly removed by boiling alcohol.

By Ivanow-Gajewsky (1873) the best produce of curcumin is stated to be obtained by washing an ethereal extract of turmeric with weak ammonia, dissolving the residue in boiling concentrated ammonia, and passing into the solution carbonic acid, by which the curcumin is precipitated in flakes.

After due recrystallization from alcohol curcumin forms yellow crystals, having an odour of vanilla, and exhibiting a fine blue in reflected light. They melt at 165° C. Curcumin is scarcely soluble, even in boiling water, but dissolves readily on addition of an alkali either caustic or carbonate. On acidulating these solutions, a yellow powder of curcumin is precipitated. Curcumin is not abundantly dissolved by ether, very sparingly by benzol or bisulphide of carbon. It is not volatile; heated with zinc dust it yields an oil boiling at 290°; fused with caustic potash, curcumin affords protocatechuic acid (page 243).

Paper tinged with an alcoholic solution of curcumin displays on addition of an alkali a brownish-red coloration, becoming violet on drying. Boracic acid produces an orange tint, turning blue by addition of an alkaline solution.[2372] This behaviour of (impure) curcumin was pointed out by Vogel as early as 1815, and has since that time been utilized as a chemical test.

[2372] The following is a striking experiment, showing some of these changes of colour:—Place a little crushed turmeric or the powder on blotting paper, and moisten it repeatedly with chloroform, allowing the latter to evaporate. There will thus be formed on the paper a yellow stain, which on addition of a slightly acidulated solution of borax and drying assumes a purple hue. If the paper is now sprinkled with dilute ammonia it will acquire a transient blue. This reaction enables one to recognize the presence of turmeric in powdered rhubarb or mustard.

Borax added to an alcoholic solution of curcumin gives rise to a crystallizable substance, which Ivanow-Gajewsky (1870) isolated by heating an alcoholic extract of turmeric with boracic and sulphuric acids. It forms a purple crystalline powder with a metallic green lustre, insoluble in water, but soluble in alcohol. Its solution is coloured dark blue by an alkali.

According to the same chemist there also exists in curcuma an alkaloid in very small quantity. Kachler (1870) found in the aqueous decoction an abundance of _bioxalate of potassium_.

=Commerce=—In the year 1869 there were imported into the United Kingdom 64,280 cwt. of turmeric; in 1870, 44,900 cwt.,—a very large proportion being furnished by Bengal and Pegu. The export from Calcutta[2373] in the year 1870-71 was 59,352 cwt.

Bombay exported in the year 1871-72, 29,780 cwt., of which the greater portion was shipped to Sind and the Persian Gulf, and only 910 cwt. to Europe.[2374]

=Uses=—Turmeric is employed as a condiment in the shape of curry powder, and as such is often sold by druggists; but as a medicine it is obsolete. It is largely consumed in dyeing.

=Substitute=—_Cochin Turmeric_ is the produce of some other species of _Curcuma_ than _C. longa_. It consists exclusively of a bulb-shaped rhizome of large dimensions, cut transversely or longitudinally into slices or segments. The cortical part is dull brown; the inner substance is horny and of a deep orange-brown, or when in thin shavings of a brilliant yellow. Mr. A. Forbes Sealy of Cochin has been good enough to send us (1873) living rhizomes of this _Curcuma_, which he states is mostly grown at Alwaye, north-east of Cochin, and is never used in the country as _turmeric_, though its starchy tubers are employed for making arrowroot. The rhizomes sent are thick, short, conical, and of enormous size, some attaining as much as 2½ inches in diameter. Internally they are of a bright orange-yellow.

The beautiful figures of Roscoe[2375] show several species of Curcuma and Zingiber provided with yellow tubers or rhizomes, all probably containing curcumin.

[2373] Returns quoted at p. 571, note 2.

[2374] _Statement of the Trade and Navigation of Bombay for_ 1871-72, pt. ii. 95.

[2375] _Monandrous Plants of the order Scitamineæ_, Liverpool, 1828, especially _Zingiber Cossumunar_.

RHIZOMA GALANGÆ.

_Radix Galangæ[2376] minoris_; _Galangal_; F. _Racine de Galanga_; G. _Galgant_.

=Botanical Origin=—_Alpinia officinarum_ Hance,[2377] a flag-like plant, with stems about 4 feet high, clothed with narrow lanceolate leaves, and terminating in short and simple racemes of elegant white flowers, shaded and veined with dull red. It grows cultivated in the island of Hainan in the south of China, and, as is supposed, in some of the southern provinces of the Chinese Empire.

[2376] _Galanga_ appears to be derived from the Arabic name _Khulanjan_, which in turn comes from the Chinese _Kau-liang Kiang_, signifying, as Dr. F. Porter Smith has informed us, _Kau-liang ginger_. Kau-liang is the ancient name of a district in the province of Kwangtung.

[2377] _Journ. of Linnean Society_, Botany, xiii. (1871) 1; also Trimen’s _Journ. of Bot._, ii. (1873) 175; Bentley and Trimen’s _Med. Plants_,