_Radix Calami aromatici_, _Radix Acori_; _Sweet Flag Root_; F. _Acore
odorant ou vrai_, _Roseau aromatique_; G. _Kalmus_.
=Botanical Origin=—_Acorus Calamus_ L., an aromatic, flag-like plant,
growing on the margins of streams, swamps, and lakes, from the coasts
of the Black Sea, through Southern Siberia, Central Asia, and India, as
far as Amurland, Northern China, and Japan; indigenous also to North
America. It is now established as a wild plant in the greater part of
Europe, reaching from Sicily as far north as Scotland, Scandinavia,
and Northern Russia; and is cultivated to a small extent in Burma and
Ceylon.
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]
[2524] Ramusio, _Raccolta delle Navigationi et Viaggi_, Venet. i. 97.
[2525] Kunstmann, _Abhandlungen der Baierischen Akademie der
Wissenschaften_, vii. (1855) 342. et seq.
[2526] _Teutsche Speiskammer_, Strassburg, 1550. ciiii.
[2527] _Rariorum Stirpium Historia_, Antv. 1576. 520.
[2528] _Hortus medicus et philosophicus_, Francof. 1588. 5.
[2529] _Treasury of Drugs_, ed. ii. 1724. 115.
[2530] See also Trimen in _Journ. of Botany_, ix. (1871) 163.
=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.
[2531] _Mat. Med. of Hindoostan_, Madras, 1813. 54.
[2532] Exod. xxx. 23; Cant. iv. 14; Ezek. xxvii. 19.—See also page 715,
footnote 2.
[2533] _In Diosc. de Mat. Med. Enarrationes_, Argent. 1554. 33.
[2534] _Hortus Malabar_, xi (1692) tab. 48. 49.
[2535] Flückiger, _Documente_ (quoted page 562), 78.
[2536] _Apparatus Medicaminum_, v. 40.
=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.
The bitter principle _Acorin_ was extracted by Faust in 1867, as a
semi-fluid, brownish glucoside, containing nitrogen, soluble both
in ether and in alcohol, but neither in benzol nor in water. In
order to obtain this substance, we precipitated the decoction of 10
lb. of the drug by means of tannic acid, and followed the method
commonly practised in the preparation of bitter principles. By finally
exhausting the residue with chloroform, we succeeded in obtaining a
very bitter, perfectly crystalline body, but in so minute a quantity,
that we were unable to investigate its nature.
=Uses=—Sweet Flag is an aromatic stimulant and tonic, now rarely used
in regular medicine. It is sold by the herbalist for flavouring beer,
and for masticating to clear the voice. It is said to be also used by
snuff manufacturers.
=Adulteration=—The rhizome of the Yellow Flag, _Iris Pseudacorus_ L.,
is occasionally mixed with that of the Sweet Flag, from which it may be
distinguished by its want of aroma, astringent taste, dark colour, and
dissimilar structure.
[2537] This was possibly alluded to by Albertus Magnus (A.D.
1193-1280), who says:—(Calamus aromaticus)—nascitur in India et
Ethiopia sub cancro, et habet interius ex parte concava “pellem
subtilem, _sicut telæ sunt aranearum_.”—_De Vegetabilibus_, Jessen’s
ed. 1867. 376. We suppose the drug under notice was intended.
[2538] Hence the practice of _peeling_ the rhizome which prevails in
some parts of the Continent ought to be abandoned.