I.—PHÆNOGAMOUS OR FLOWERING PLANTS. (continued 22)

HORDEUM DECORTICATUM.

Hordeum perlatum, Fructus vel Semen Hordei; Pearl Barley; F. Orge mondé ou perlé; G. Gerollte Gerste, Gerstegraupen.

Botanical Origin—Hordeum distichum L.,—the Common or Long-eared Barley is probably indigenous to western temperate Asia, but has been cultivated for ages throughout the northern hemisphere. In Sweden its cultivation extends as far as 68° 38’ N. lat.; on the Norwegian coast up to the Altenfjord in 70° N. lat.; even in Lapland, it succeeds as high as 900 to 1350 feet above the level of the sea. In several of the southern Swiss Alpine valleys, barley ripens at 5000 feet, and in the Himalaya at 11,000 feet. In the Equatorial Andes, where it is extensively grown, it thrives up to at least 11,000 feet above the sea. No other cereal can be cultivated under so great a variety of climate.

According to Bretschneider,[2699] barley is included among the five cereals which it is related in Chinese history were sowed by the Emperor Shen-nung, who reigned about 2700 b.c.; but it is not one of the five sorts of grain which are used at the ceremony of ploughing and sowing as now annually performed by the emperors of China.

Theophrastus was acquainted with several sorts of barley (Κριθή), and among them, with the six-rowed kind or hexastichon, which is the species that is represented on the coins struck at Metapontum[2700] in Lucania, between the 6th and 2nd centuries b.c.

Strabo and Dioscorides in the 1st century allude to drinks made from barley, which according to Tacitus were even then familiar to the German tribes, as they are known to have been still earlier to the Greeks and Egyptians.

Barley is mentioned in the Bible as a plant of cultivation in Egypt and Syria, and must have been, among the ancient Hebrews, an important article of food, judging from the quantity allowed by Solomon to the servants of Hiram, king of Tyre (b.c. 1015). The tribute of barley paid to King Jotham by the Ammonites (b.c. 741) is also exactly recorded. The ancients were frequently in the practice of removing the hard integuments of barley by roasting it, and using the torrefied grain as food.

Manufacture—For use in medicine and as food for the sick, barley is not employed in its crude state, but only when deprived more or less completely of its husk. The process by which this is effected is carried on in mills constructed for the purpose, and consists essentially in passing the grain between horizontal millstones, placed so far apart as to rub off its integuments without crushing it. Barley partially deprived of its husk is known as Scotch, hulled or Pot Barley. When by longer and closer grinding the whole of the integuments have been removed, and the grain has become completely rounded, it is termed Pearl Barley. In the British Pharmacopœia it is this sort alone which is ordered to be used.

Description—Pearl Barley is in subspherical or somewhat ovoid grains about 2 lines in diameter, of white farinaceous aspect, often partly yellowish from remains of the adhering husk, which is present on the surface, as well as in the deep longitudinal furrow with which each grain is indented. It has the farinaceous taste and odour which are common to most of the cereal grains.

Microscopic Structure—The albumen which constitutes the main portion of the grain is composed of large thin-walled parenchyme, the cells of which on transverse section are seen to radiate from the furrow, and to be lengthened in that direction rather than longitudinally. In the vicinity of the furrow alone the tissue of the albumen is narrower. Its predominating large cells show a polygonal or oval outline, whilst the outer layer is built up of two, three or four rows of thick-walled, coherent, nearly cubic gluten-cells. This layer, about 70 mkm. thick, is coated with an extremely thin brown tegument, to which succeeds a layer about 30 mkm. thick, of densely packed, tabular, greyish or yellowish cells of very small size; this proper coat of the fruit in the furrow is of rather spongy appearance.

In some varieties of barley the fruit is constituted of the above tissues alone and the shell, but in most the paleæ are likewise present. They consist chiefly of long fibrous, thick-walled cells, two or four rows deep, constituting a very hard layer. On tranverse section, this layer forms a coherent envelope about 35 mkm. thick; its cells when examined in longitudinal section show but a small lumen of peculiar undulated outline from secondary deposits.

The gluten-cells varying considerably in the different cereal grains, afford characters enough to distinguish them with certainty. In wheat, for instance, the gluten-cells are in a single row, in rice they form a double or single row, but its cells are transversely lengthened.

The inner tissue of the albumen in barley is filled up with large irregularly lenticular, and with extremely small globular starch granules, the first being 20 to 35 mkm., the latter 1, 2 to 3 mkm. in diameter, with no considerable number of intermediate size. The concentric layers constituting the large granules may be made conspicuous by moistening with chromic acid.

The layer alluded to as being composed of gluten-cells is loaded with extremely small granules of albuminous matters (gluten), which on addition of iodine are coloured intensely yellow. These granules, which, considering barley as an article of food, are of prominent value, are not confined to the gluten-cells, but the neighbouring starch-cells also contain a small amount of them: and in the narrow zone of denser tissue projecting from the furrow into the albumen, protein principles are equally deposited, as shown by the yellow coloration which iodine produces.

The gluten-cells, the membrane embroynnaire of Mège-Mouriès, contain also, according to the researches on bread[2701] made by this chemist (1856), Cerealin, an albuminous principle soluble in water, which causes the transformation of starch into dextrin, sugar, and lactic acid. In the husks (épiderme, épicarpe and endocarpe) of wheat, Mège-Mouriès found some volatile oil and a yellow extractive matter, to which, together with the cerealin, is due the acidity of bread made with the flour containing the bran.

Chemical Composition—Barley has been submitted to careful analyses by many chemists, more especially by Lermer.[2702] The grains contain usually 13 to 15 per cent. of water; after drying, they yield to ether 3 per cent. of fat oil, with insignificant proportions of tannic and bitter principles, residing chiefly in the husks. Lermer further found in the whole grains, 63 per cent. of starch, 7 of cellulose, 6·6 of dextrin, 2·5 of nitrogen, a small amount of lactic acid, and 2·4 of ash.

The analysis of Poggiale (1856) gave nearly the same composition, namely, water 15, oil 2·4, starch 60, cellulose 8·8, albuminous principles 10·7, ash 2·6.

The protein, or albuminous matter consists of different principles, chiefly insoluble in cold water. The soluble portion is partly coagulated on boiling, partly retained in solution: 2·5 per cent. of nitrogen, as above, would answer to about 16 per cent. of albuminous matters. Their soluble part seems to be deposited in the starch-cells, next to the gluten-cells, which latter contain the insoluble portion.

The ash, according to Lermer, contains 29 per cent. of silicic acid, 32·6 of phosphoric acid, 22·7 of potash, and only 3·7 of lime. In the opinion of Salm-Horstmar, fluorine and lithia are indispensable constituents of barley.

The fixed oil of barley, as proved in 1863 by Hanamann, is a compound of glycerin with either a mixture of palmitic and lauric acids, or less probably with a peculiar fatty acid. Beckmann’s Hordeinic Acid obtained in 1855 by distilling barley with sulphuric acid, is probably lauric acid. Lintner (1868) has shown barley to contain also a little Cholesterin (p. 420).

Lastly, Kühnemann (1875) extracted from barley a crystallized dextrogyrate sugar, and (1876) an amorphous lævogyrate mucilaginous substance Sinistrin (see p. 692); according to that chemist, dextrin is altogether wanting in barley.

Barley when malted loses 7 per cent.; it then contains 10 to 12 per cent. of sugar, produced at the expense of the starch; before malting, no sugar is to be found.

Uses—Barley as a medicine is unimportant. A decoction is sometimes prescribed as a demulcent or as a diluent of active remedies. An aqueous extract of malt has been employed.

OLEUM ANDROPOGONIS.

Oleum Graminis Indici; Indian Grass Oil.

Botanical Origin—Among the numerous species of Andropogon[2703] which have foliage abounding in essential oil, the following furnish the fragrant Grass Oils of commerce:—

1. Andropogon Nardus L.,[2704]—a noble-looking plant, rising when in flower to a height of 6 or more feet, extensively cultivated in Ceylon and Singapore for the production of Citronella Oil.

2. A. citratus D.C.,[2705] Lemon Grass,—a large coarse glaucous grass, known only in a cultivated state, and very rarely producing flowers. It is grown in Ceylon and Singapore for the sake of its essential oil, which is called Lemon Grass Oil, Oil of Verbena or Indian Melissa Oil; it is also commonly met with in gardens throughout India and is not unfrequent in English hothouses. In Java it is called Sireh.

3. A. Schœnanthus L.,[2706] a grass of Northern and Central India, having leaves rounded or slightly cordate at the base, yielding by distillation the oil known as Rúsa Oil, Oil of Ginger Grass or of Geranium.

History—The aromatic properties of certain species of Andropogon were well known to Rheede, Rumphius, and other early writers on Indian natural history; and an oil distilled from the Sireh grass in Amboyna was known as a curiosity as early as 1717.[2707]

But it is only in very recent times that the volatile oils of these plants have become objects of commerce with Europe. Lemon grass oil is mentioned by Roxburgh in 1820 as being distilled in the Moluccas; and it was first imported into London about the year 1832. Citronella oil is of much more recent introduction. Ginger grass oil, called in Hindustani Rúsa ka tel, is stated by Waring[2708] to have been first brought to notice by Dr. N. Maxwell in 1825.

Production—Citronella and Lemon grass are cultivated about Galle and at Singapore, the same estate often producing both. The grasses are distilled separately, the essential oils being regarded as entirely distinct, and having different market values. In Ceylon they are cut for distillation at any time of year, but mostly in December and January.

On the Perseverance Estate at Gaylang, Singapore, belonging to Mr. John Fisher, an area of 950 acres is cultivated with aromatic grasses and other plants, for the production of essential oils. The manufacture was tried on a small scale in 1865, and has been so successful that an aggregate of 200 lb. of various essential oils is now produced daily. These oils are stated to be Citronella, Lemon Grass, Patchouly, Nutmeg, Mace, Pepper, and Oman (p. 302): and mint is now being cultivated.[2709]

Ginger grass oil is distilled in the collectorate of Khandesh in the Bombay Presidency. That produced in the district of Namár in the valley of the Nerbudda, is sometimes called Grass Oil of Namar. We have no particulars of the distillation, which however must be carried on extensively.

Description—The Indian grass oils are lighter than water, devoid of rotatory power when examined by polarized light, and do not alter litmus paper. They are all extremely fragrant, having an odour like a mixture of lemon and rose. Lemon grass, which in colour is a deep golden brown, has an odour resembling that of the sweet-scented verbena of the gardens, Lippia citriodora H.B.K. Ginger grass oil, the colour of which varies from pale greenish yellow to yellowish-brown, has the odour of Pelargonium Radula Aiton. The colour of citronella oil is a light greenish yellow. The manufacture of Winter of Ceylon, and of Fisher of Singapore, have a reputation for excellence, and are generally indicated by name in drug sale catalogues.

Chemical Composition—Stenhouse[2710] examined in 1844 oil of ginger grass given to him by Christison as Oil of Namur (or Nimar). The sample was of deep yellow, and apparently old, for when mixed with water and subjected to distillation, it left nearly one half its bulk of a fluid resin, the oil which passed over being colourless. After rectification from chloride of calcium, it was shown to consist of a hydrocarbon mixed with a small proportion of an oxygenated oil. The latter having been decomposed by sodium, and the oil again rectified, a second analysis was made which proved it isomeric with oil of turpentine.

A genuine grass oil from Khandesh, derived as we suppose from the same species, which was examined by one of us (F.), yielded nothing crystalline when saturated with dry hydrochloric acid; but when the liquid was afterwards treated with fuming nitric acid, crystals of the compound, C₁₀H₁₆, HCl, sublimed into the upper part of the vessel. We have observed that the oils both of lemon grass and citronella yield solid compounds, if shaken with a saturated solution of bisulphite of sodium.

Citronella oil was found by Gladstone (1872) to be composed chiefly of an oxidized oil, which he called Citronellol, and which he separated by fractional distillation into two portions, the one boiling at 202-205° C., the other 199-202° C. The composition of each portion is indicated by the formula C₁₀H₁₆O.

Wright’s researches (1874) tend rather to show the prevailing part of citronella oil to consist of the liquid C₁₀H₁₈O, boiling near 210°, which he calls Citronellol. It unites with bromine, and the resulting compound, upon heating, breaks up according to the following equation:—

C₁₀H₁₈OBr₂ = OH₂ · 2 HBr · C₁₀H₁₄.

Cymene.

Commerce—The growing trade in grass oil is exemplified in a striking manner by the following statistics. The export of Citronella Oil from Ceylon in 1864 was 622,000 ounces, valued at £8230. In the Ceylon Blue Book, the exports for 1872 are returned thus:—

To the United Kingdom 1,163,074 ounces 1,595,257 ounces.[2711]

British India 5,713 ”

United States of North America 426,470 ”

In 1875 the oil shipped from Ceylon to the United Kingdom was valued at 42,871 rupees, that sent to other foreign countries at 45,871 rupees, to British possessions 660 rupees (one rupee equal to about 2s.).

Oil of Lemon Grass, which is a more costly article and less extensively produced, was exported from Ceylon during the same year to the extent of 13,515 ounces, more than half of which quantity was shipped to the United States. There are no analogous statistics for these two oils from Singapore, where, as stated at p. 726, they are now largely manufactured.

By the official Report on the External Commerce of Bombay, published in 1867, we find that during the year ending 31 March, 1867, Grass Oil [i.e. Ginger Grass or Rúsa Oil] was exported thence to the amount of 41,643 lb. This oil is shipped to England and to the ports of the Red Sea.

Uses—Grass oils are much esteemed in India as an external application in rheumatism. Rúsa oil is said to stimulate the growth of the hair. Internally, grass oil is sometimes administered as a carminative in colic; and an infusion of the leaves of lemon grass is prescribed as a diaphoretic and stimulant. In Europe and America the oils are used almost exclusively by the soapmakers and perfumers.[2712]

But the most remarkable use made of any grass oil is that for adulterating Attar of Rose in European Turkey. The oil thus employed is that of Andropogon Schœnanthus L. (see p. 725); and it is a curious fact that its Hindustani name is closely similar in sound to the word rose. Thus under the designation Rusa, Rowsah, Rosa, Rosé, Roshé,[2713] it is exported in large quantities from Bombay to the ports of Arabia, probably chiefly to Jidda, whence it is carried to Turkey by the Mahommedan pilgrims. In Arabia and Turkey, it appears under the name Idris yàghi, while in the attar-producing districts of the Balkan it is known, at least to Europeans, as Geranium Oil or Palmarosa Oil. Before being mixed with attar, the oil is subjected to a certain preparation, which is accomplished by shaking it with water acidulated with lemon juice, and then exposing it to the sun and air. By this process, described by Baur,[2714] the oil loses a penetrating after-smell, and acquires a pale straw-colour. The optical and chemical differences between grass oil thus refined and attar of rose are slight and do not indicate a small admixture of the former. If grass oil is added largely to attar, it will prevent its congealing.

Adulteration—The grass oil prepared by the natives of India is not unfrequently contaminated with fatty oil.

Other Products of the genus Andropogon.

Herba Schœnanthi vel Squinanthi, Juncus odoratus, Fœnum Camelorum.

The drug bearing these names has had a place in pharmacy from the days of Dioscorides down to the middle of the last century, and is still met with in the East. The plant which affords it, formerly confounded with other species, is now known to be Andropogon laniger Desf., a grass of wide distribution, growing in hot dry regions in Northern Africa (Algeria), Arabia, and North-western India, reaching Thibet, where it is found up to an elevation of 11,000 feet. Mr. Tolbort has sent us specimens under the name of Kháví, gathered by himself in 1869 between Multán and Kot Sultán, and quite agreeing with the drug of pharmacy. The grass has an aromatic pungent taste, which is retained in very old specimens. We are not aware that it is distilled for essential oil.

Cuscus or Vetti-ver[2715]—This is the long fibrous root of Andropogon muricatus Retz, a large grass found abundantly in rich moist ground in Southern India and Bengal. Inscriptions on copper-plates lately discovered in the district of Etawah, south-east of Agra, and dating from a.d. 1103 and 1174, record grants of villages to Brahmins by the kings of Kanauj, and enumerate the imposts that were to be levied. These include taxes on mines, salt pits and the trade in precious metals, also on mahwah (Bassia) and mango trees, and on Cuscus Grass.[2716]

Cuscus, which appears occasionally in the London drug sales, is used in England for laying in drawers as a perfume. In India it serves for making tatties or screens, which are placed in windows and doorways, and when wetted, diffuse an agreeable odour and coolness. It is also used for making ornamental baskets and many small articles, and has some reputation as a medicine.

RHIZOMA GRAMINIS.

Radix Graminis; Couch Grass, Quitch Grass, Dog’s Grass; F. Chiendent commun ou Petit Chiendent; G. Queckenwurzel, Graswurzel.

Botanical Origin—Agropyrum repens P. Beauv. (Triticum repens L.), a widely diffused weed, growing in fields and waste places in all parts of Europe, in Northern Asia down to the region south of the Caspian, also in North America; and in South America to Patagonia and Tierra del Fuego.

History—The ancients were familiar with a grass termed [Greek Agrôstis] and Gramen, having a creeping rootstock like that under notice. It is impossible to determine to what species the plant is referable, though it is probable that the grass Cynodon Dactylon Pers., as well as Agropyrum repens, was included under these names.

Dioscorides asserts that its root taken in the form of decoction, is a useful remedy in suppression of urine and vesical calculus. The same statements are made by Pliny; and again occur in the writings of Oribasius[2717] and Marcellus Empiricus[2718] in the 4th, and of Aëtius[2719] in the 6th century, and are repeated in the mediæval herbals,[2720] where also figures of the plant may be found, as for instance in Dodonæus. The drug is also met with in the German pharmaceutical tariffs of the 16th century. Turner[2721] and Gerarde both ascribe to a decoction of grass root diuretic and lithontriptic virtues. The drug is still a domestic remedy in great repute in France, being taken as a demulcent and sudorific in the form of tisane.

Description—Couch-grass has a long, stiff, pale yellow, smooth rhizome, ⅒ of an inch in diameter, creeping close under the surface of the ground, occasionally branching, marked at intervals of about an inch by nodes, which bear slender branching roots and the remains of sheathing rudimentary leaves.

As found in the shops, the rhizome is always free from rootlets, cut into short lengths of ⅛ to ¼ of an inch, and dried. It is thus in the form of little, shining, straw-coloured, many-edged, tubular pieces, which are without odour, but have a slightly sweet taste.

Microscopic Structure—A transverse section of this rhizome shows two different portions of tissue, separated by the so-called nucleus-sheath. The latter consists of an unbroken ring of prismatic cells, analogous to those occurring in sarsaparilla. In Rhizoma Graminis, the outer part of the tissue exhibits a diffuse circle of about 20 liber bundles, and the interior part about the same number of fibro-vascular bundles more densely packed. The pith is reduced to a few rows of cells, the rhizome being always hollow, except at the nodes. No solid contents are to be met with in the tissue.

Chemical Composition—The constituents of couch-grass include no substance to which medicinal powers can be ascribed. The juice of the rhizome afforded to H. Müller[2722] about 3 per cent. of sugar, and 7 to 8 per cent. of Triticin, C₁₂H₂₂O₁₁, a tasteless, amorphous, gummy substance, easily transformed into sugar if its concentrated solution is kept for a short time at 110°C. When treated with nitric acid, it yields oxalic acid. The rhizome affords also another gummy matter containing nitrogen, and quickly undergoing decomposition; the drug moreover is somewhat rich in acid malates. Mannite is probably occasionally present as in taraxacum (p. 394), for such is the inference we draw from the opposite results obtained by Stenhouse and by Völcker. Starch, pectin and resin are wanting. The rhizome leaves 4½ per cent. of ash.

Uses—A decoction of the rhizome has of late been recommended in mucous discharge from the bladder.

Substitutes—Agropyrum acutum R. et S., A. pungens R. et S., and A. junceum P. Beauv., by some botanists regarded as mere maritime varieties of A. repens, have rootstocks perfectly similar to this latter.

Cynodon Dactylon Pers., a grass very common in the South of Europe and the warmer parts of Western Europe, also indigenous to Northern Africa as far as Sennaar and Abyssinia, affords the Gros Chiendent or Chiendent pied-de-poule of the French. It is a rhizome differing from that of couch-grass in being a little stouter. Under the microscope it displays an entirely different structure, inasmuch as it contains a large number of much stronger fibro-vascular bundles, and a cellular tissue loaded with starch, and is therefore in appearance much more woody. It thus approximates to the rhizome of Carex arenaria L., which is as much used in Germany as that of Cynodon in Southern Europe. The latter appears to contain Asparagin (the Cynodin of Semmola[2723]), or a substance similar to it.