Regarding the introduction of Acorus Calamus into Western Europe, it is believed in Poland to have been introduced there in the 13th century by the Tartars, yet it seems not to have attracted then any attention. The well-informed botanist, Bock (Tragus), mentioning the use of the preserved rhizome by wealthy persons, states[2526] that he had never seen the plant growing in Germany. Clusius[2527] relates that he first received a living plant in 1574, sent from the lake Apollonia near Brussa in Asia Minor. Camerarius,[2528] writing in 1588, speaks of it as introduced some years previously, and then plentiful in Germany, which seems to show a rapid propagation. Gerarde at the close of the century looked upon Acorus as an Eastern plant, which he says is grown in many English gardens, and might hence be fitly called the “Sweet Garden Flag.” Berlu,[2529] in 1724, observes of the root that—“it is brought in quantities from Germany:” hence we may infer that it was not then collected in England, as we know it was at a later period.[2530]
History—Sweet Flag root has been from the earliest times a favourite medicine of the natives of India, in which country it is sold in every bazaar. Ainslie[2531] asserts that it is reckoned so valuable in the bowel complaints of children that there is a penalty incurred by any druggist who will not open his door in the middle of the night to sell it, if demanded!
The descriptions of Acoron, a plant of Colchis, Galatia, Pontus, and Crete, given by Dioscorides and Pliny, certainly refer to this drug. We think that the Κάλαμος ἀρωματικός of Dioscorides, which he states to grow in India, is the same, though Royle regards it as an Andropogon. The Κάλαμος of Theophrastus and the Calamus of the English Bible[2532] are considered by some authors to refer to the Sweet Flag.
Celsus in the first century mentioned Calamus Alexandrinus, the drug being probably then brought from India by way of the Red Sea. We know by the testimony of Amatus Lusitanus[2533] that in the 16th century it used to be so imported into Venice. Rheede,[2534] moreover, described and figured Acorus Calamus as an Indian plant under the name Vacha, which it still bears on the Malabar Coast. But in the pharmaceutical tariff of the German town of Halberstadt of the year 1697, “Calamus aromaticus verus, Indianischer Calmus” and “Calamus aromaticus nostras,” common Calmus, are quoted at exactly the same price,[2535] and Murray[2536] states expressly that in his time (1790) Asiatic calamus was still met with in the pharmacies of Continental Europe, but that it had mostly been replaced by the home-grown drug. At the present time the Calamus aromaticus of commerce is European; in all essential characters it agrees with that of India, a package of which is now and then offered in the London drug sales.
Collection—The London market is supplied from Germany, whither the drug is brought, we believe, from Southern Russia. It is no longer collected in England,—at least in quantity, though it used to be gathered some years ago in Norfolk.
Description—The rootstock of sweet flag occurs in somewhat tortuous, subcylindrical or flattened pieces, a few inches long, and from ½ to 1 inch in greatest diameter. Each piece is obscurely marked on the upper surface with the scars, often hairy, of leaves, and on the under with a zigzag line of little, elevated, dot-like rings,—the scars of roots. The rootstock is usually rough and shrunken, varying in colour from dark brown to orange-brown, breaking easily with a short corky fracture, and exhibiting a pale brown spongy interior. The odour is aromatic and agreeable; the taste, bitterish and pungent.
The fresh rootstock is brownish-red or greenish, white or reddish within, and of a spongy texture. Its transverse section is tolerably uniform; a fine line (medullary sheath) separates the outer tissue from the lighter central part, the diameter of which is twice or three times the width of the former.
Microscopic Structure—The outermost layer is made up of extended epiblema-cells or of a brown corky tissue, the latter occurring in the parts free from leaf-scars. The prevailing tissue, both of the outer and the central part, consists of uniform nearly globular cells, traversed by numerous vascular bundles, especially at the boundary line (medullary sheath). Besides them, the rootstock like that of many fresh-water plants, exhibits a large number of intercellular holes. These air-holes, or more correctly water-holes, are somewhat longitudinally extended, so as to form a kind of network, imparting a spongy consistence[2537] to the fresh rootstock. At certain places, where the series of cells cross one another, especially in the outer part, there are single cells filled with essential oil,[2538] which may be made very conspicuous by adding to sections dilute potash or perchloride of iron. The other cells are loaded with small starch granules; a little mucilage and tannic matter is met with in the exterior coat.
Chemical Composition—The dried rhizome yielded us 1·3 per cent. of a yellowish neutral essential oil of agreeable odour, which in a column of 50 mm. long, deviates 13·8° to the right. By working on a large scale, Messrs. Schimmel & Co., Leipzig, obtain 2·4 to 2·6 per cent.
According to Kurbatow (1873), this oil contains a hydrocarbon, C₁₀H₁₆, boiling at 159° C., and forming a crystalline compound with HCl, and another hydrocarbon boiling at 255-258° C., affording no crystallizable hydrochloric compound. By submitting the oil to fractional distillation, we noticed, above 250°, a blue portion, which may be decolorized by sodium. The crude oil acquires a dark brownish colour on addition of perchloride of iron, but is not at all soluble in concentrated potash solution.