HAMAMELIDEÆ.
STYRAX LIQUIDUS.[1035]
Balsamum Styracis; Liquid Storax; F. Styrax liquide; G. Flüssiger Storax.
Botanical Origin—Liquidambar orientalis Miller (L. imberbe Aiton), a handsome, umbrageous tree resembling a plane, growing to the height of 30 to 40 feet or more,[1036] and forming forests in the extreme south-western part of Asia Minor. In this region the tree occurs in the district of Sighala near Melasso, about Budrum (the ancient Halicarnassus) and Moughla, also near Giova and Ullà in the Gulf of Giova, and lastly near Marmorizza and Isgengak opposite Rhodes. It also grows in the valley of the El-Asi (the ancient Orontes), as proved by a specimen in the Vienna herbarium, collected by Gödel, Austrian Consul at Alexandretta. In this locality it was seen by Kotschy in 1835, but mistaken for a plane. The same traveller informed one of us that he believed it to occur at Narkislik, a village near Alexandretta.
The tree is not known to grow in Cyprus, Candia, Rhodes, Kos, or indeed in any of the islands of the Mediterranean.[1037]
History—Two substances of different origin have been known from a remote period under the name of Styrax or Storax, namely the resin of Styrax officinalis L. (see further on), and that of Liquidambar orientalis Miller, the latter commonly distinguished as Liquid Storax.
According to Krinos of Athens, who has carefully investigated the history of the drug,[1038] the earliest allusions to Liquid Storax occur in the writings of Aëtius and of Paulus Ægineta,[1039] who name both Storax and Liquid Storax (στνραξ νγρὸϛ). Of these Greek physicians, who lived respectively in the 6th and 7th centuries, the second also mentions the resin of Ζυγία, which is regarded by Krinos as synonymous with the latter substance.[1040]
We find in fact the term Sigia frequently mentioned by Rhazes (10th century) as signifying Liquid Storax. This and other Arabian physicians were also familiar with the same substance under the name of Miha (may’a), and also knew how and whence it was obtained.[1041]
A curious account of the collecting of Liquid Storax from the tree Zygia, and from another tree called Stourika, is given in the travels through Asia Minor to Palestine of the Russian abbot of Tver in a.d. 1113-1115.[1042]
The wide exportation and ancient use of Liquid Storax are very remarkable: even in the first century, as appears by the author of the Periplus of the Erythrean Sea, Storax, by which term there can be but little doubt Liquid Storax was intended, was exported by the Red Sea to India. Whether the Storax and Storax Isaurica offered to the Church of Rome under St. Silvester, a.d. 314-335, by the emperor Constantine,[1043] was Liquid Storax or the more precious resin of Styrax officinalis L., is a point we cannot determine. That the Chinese used the drug was a fact known to Garcia de Orta (1535-63): Bretschneider[1044] has shown from Chinese sources that, together with olibanum and myrrh, it was imported by the Arabs into China during the Ming dynasty, a.d. 1368-1628. This trade is still carried on: the drug is conveyed by way of the Red Sea to Bombay, and thence shipped to China. Official returns show that the quantity thus exported from Bombay in the year 1856-57 was 13,328 lb. In the time of Kämpfer (1690-92), Liquid Storax was one of the most profitable articles of shipment to Japan.[1045]
Liquid Storax is known in the East, at least in the price-currents and trade statistics of Europeans, by the strange-sounding name of Rose Malloes (Rosa Mallas, Rosum Alloes, Rosmal), a designation for it in use in the time of Garcia de Orta. Clusius[1046] considered it to be Arabic, which, however, the scholars whom we have consulted do not allow. Others identify it with Rasamala, the Malay name for Altingia excelsa. (See further on.)
The botanical origin of Liquid Storax was long a perplexing question to pharmacologists. It was correctly determined by Krinos, but his information on the subject published in a Greek newspaper in 1841, and repeated by Kosté in 1855,[1047] attracted no attention in Western Europe. The question was also investigated by one of the authors of the present work, whose observations, together with a figure of Liquidambar orientalis Miller, were published in 1857.[1048]
Method of Extraction—The extraction of Liquid Storax is carried on in the forests of the south-west of Asia Minor, chiefly by a tribe of wandering Turcomans called Yuruks. The process has been described on the authority of Maltass and McCraith of Smyrna, and of Campbell, British Consul at Rhodes.[1049] The outer bark is said to be first removed from the trunk of the tree and rejected; the inner is then scraped off with a peculiar iron knife or scraper, and thrown into pits until a sufficient quantity has been collected. It is then boiled with water in a large copper, by which process the resin is separated, so that it can be skimmed off. This seems to be performed with sea water; some chloride of sodium can therefore be extracted from the drug. The boiled bark is put into hair bags and squeezed under a rude lever, hot water being added to assist in the separation of the resin, or as it is termed yagh, i.e. oil. Maltass states that the bark is pressed in the first instance per se, and afterwards treated with hot water. In either case the products obtained are the opaque, grey, semi-fluid resin known as Liquid Storax, and the fragrant cakes of foliaceous, brown bark, once common[1050] but now rare in European pharmacy, called Cortex Thymiamatis.
We are indebted to M. Felix Sahut of Montpellier for a specimen of the bark of Liquidambar orientalis, cut from the trunk of a fine tree on his property at the neighbouring village of Lattes. The bark which is covered with a very thick corky layer and soaked in its own fragrant resin, shows no tendency to exfoliate. The investigations of Unger[1051] in Cyprus are consequently to us inexplicable; he asserts that the bark scales off, like that of the plane, by continued exfoliation, which is not the case with that of M. Sahut’s tree.
Description—Liquid Storax is a soft viscid resin, usually of the consistence of honey, heavier than water, opaque and greyish brown. It always contains water, which by long standing rises to the surface. In one sample that had been kept more than 20 years, the resin at the bottom of the bottle formed a transparent layer of a pale golden brown. When liquid storax is heated, it becomes by the loss of water dark brown and transparent, the solid impurities settling to the bottom. Spread out in a very thin layer, it partially dries, but does not wholly lose its stickiness. When free from water (which reddens litmus) it dissolves in alcohol, spirit of wine, chloroform, ether, glacial acetic acid, bisulphide of carbon, and most of the essential oils, but not in the most volatile part of petroleum (“petroleum ether”). It has a pleasant balsamic smell, especially after it has been long kept; when recent, it is contaminated with an odour of bitumen or naphthalene that is far from agreeable. Its taste is sharply pungent, burning and aromatic.
When the opaque resin is subjected to microscopic examination, small brownish granules are observed in a viscid, colourless, transparent liquid, besides which large drops of a mobile watery liquid may be distinguished. In polarized light, numerous minute crystalline fragments with a few larger tabular crystals are obvious. But when thin layers of the resin are left on the object glass in a warm place, feathery or spicular crystals (styracin) shoot out on the edge of the clear liquid, while in the large, sharply-defined drops above mentioned, rectangular tables and short prisms (cinnamic acid) make their appearance. On applying more warmth after the water is evaporated, all the substances unite into a transparent, dark brown, thick liquid, which exhibits no crystalline structure on cooling, or only after a very long time. Among the fragments of the bark occurring in the crude resin, liber-fibres are frequently observable.
Chemical Composition—The most abundant constituent of Styrax is probably the Storesin, C₃₆H₅₅(OH)₃, discovered in 1877 by W. von Miller, or rather cinnamic ethers of it and of an isomeric substance. Storesin is an amorphous substance melting at 168° C., readily soluble in petroleum ether. Several other compound ethers have also been observed in the drug, as for instance cinnamic ether of phenylpropyl, cinnamic ether of ethyl, cinnamic ether of benzyl, and especially cinnamate of cinnamyl, C₉H₇O₂·C₉H₉, the so-called Styracin. This substance, discovered by Bonastre in 1827, can be removed by ether, benzol or alcohol, after the separation from the resin of the cinnamic acid; it is insoluble in water, and volatile only in super-heated steam. It crystallizes in tufts of long rectangular prisms, which melt at 38° C., but it frequently does not solidify in a crystalline form, or only after a long time, or remains as an oily liquid. In its pure state it is inodorous and tasteless. By concentrated solution of potash, it is resolved into a cinnamate, and cinnamic alcohol (Styrone) C₉H₁₀O, which latter is not present in Liquid Storax. The cinnamic acid may be extracted to a small extent by boiling water, more completely by means of a boiling solution of carbonate of sodium, as it is present in the drug partly in the free state. Its compound ethers may be decomposed by caustic lye. The yield of cinnamic acid accordingly varies from 6 to 12 per cent.—or even, according to Löwe, as much as 23 per cent. of crystallized cinnamic acid can be obtained. The acid dissolves abundantly in ether, alcohol, or hot water, slightly in cold water; it is inodorous, but has an acrid taste. It fuses at 133° C., and boils at 290° C.; at a dull red heat it is resolved into carbonic acid and styrol, which latter is therefore related to it in the same manner as benzol (benzene) to benzoic acid. Liquid styrax is in fact the best source of cinnamic acid.
Another constituent of styrax is a fragrant substance, perhaps ethylvanillin, occurring in but small quantity.
Laubenheimer (1872) has shown that probably Benzylic Alcohol, C₇H₈O, boiling at 206° C., likewise occurs in Liquid Storax; it has not been found by Miller. The latter chemist also showed that water removes from the drug a little benzoïc acid; he observed moreover a substance similar to caoutchouc among the constituents of liquid styrax.
There is further to be mentioned as having been met with in Liquid Storax a hydrocarbon, C₈H₈, first prepared by Simon in 1839, which exists in the resin as a liquid, and also in a polymeric form as a solid. The former called Styrol, Cinnamene, or Cinnamol, has a sp. gr. of 0·924, and a boiling point of 146° C. It is a colourless, mobile liquid which may be obtained by distilling with water liquid storax, the odour and burning taste of which it possesses. When heated for a considerable time to 100°, or for a shorter period to 200° C., it is converted without change of composition into the colourless, transparent solid Metastyrol, which, unlike styrol, is not soluble in alcohol or ether. It has a sp. gr. of 1·054, and may be cut with a knife. By prolonged heating, it can be converted into its original liquid form.
Styrol is to be regarded as phenylated ethylene; it can be artificially obtained by shaking powdered cinnamic acid with saturated hydrobromic acid, when crystalline hydrobromated cinnamic acid, C₆H₅·CH₂·CHBr·COOH, is formed. One part of the latter, 10 parts of water, and a little more carbonate of sodium than the quantity required for saturation are mixed. The bromhydrocinnamate of sodium partly splits up immediately, even at 0°, according to the following equation
| C₆H₅·CH₂·CHBr·COONa = | ·CO₂ + NaBr + C₆H₅·CH·CH₂. |
| Bromhydrocinnamate of sodium. |
Styrol. |
24 parts of bromhydrocinnamic acid, recrystallized from boiling bisulphide of carbon, yield about 7 parts of styrol; no other method affords as much as this.
Styrol has been discovered in Styrax, but is not regularly, and at all events to a minute amount only, found in the drug of the present day. We have no explanation for the strange fact that it was apparently more abundantly met with in former times.
Lastly there has been found in Liquid Storax, by J. H. van t’Hoff (1876), about 0·4 per cent. of an essential oil, probably C₁₀H₁₆O; Miller also pointed out a compound ether of probably the same (alcoholic) substance as occurring in styrax.
By the action of oxidizing agents, as nitric or chromic acids, or peroxide of lead, the cinnamyl compounds are easily reduced, carbonic acid and water being evolved; and at the same time benzoic acid, bitter almond oil, and hydrocyanic acid are produced. These compounds are in fact abundantly evolved when 6 parts of Liquid Storax are gently warmed with 1 p. of caustic soda, and then mixed with 3 p. of permanganate of potassium dissolved in 20 p. of water.
We have examined several samples of Liquid Storax of average quality, and found by exposure of small quantities to the heat of the steam bath, that it lost from 10 to 20 per cent. of water. The remainder treated with alcohol yielded a residue amounting to 13 to 18 per cent., consisting chiefly of fragments of bark and inorganic impurities. The percentage of the drug soluble in alcohol, to which is due its therapeutic value, thus amounts to 56 to 72. This part, as may be inferred from the foregoing statements, consists chiefly of storesin, the various compound ethers above mentioned, of cinnamic acid and of styracin, no doubt in greatly varying proportions.
Commerce—The annual production of Liquid Storax was estimated by Campbell in 1855 as about 490 cwt. for the districts of Giova and Ullá, and 300 cwt. for those of Marmorizza and Isgengak. The drug is exported in barrels to Constantinople, Smyrna, Syra and Alexandria. Some is also packed with a certain proportion of water in goatskins, and sent either by boats or overland to Smyrna, where it is transferred to barrels and shipped mostly to Trieste.
The chief consumption of Liquid Storax would appear to be in India and China. In the fiscal year 1866-67, Bombay imported 319 cwt. from the Red Sea. Liquid Storax is seldom seen in the London drug-sales.
Uses—Liquid Storax, which the British Pharmacopœia directs to be purified by solution in spirit of wine, is an ingredient in a few old-fashioned preparations but is hardly ever prescribed on its own account. It is stated to be expectorant and stimulant, and useful in chronic bronchial affections. It has been recommended by Pastau, Berlin (1865), as an external application for the cure of scabies, for which purpose it is mixed with linseed oil and now largely used.
Adulteration—The drug is occasionally mixed with sand, ashes, and other substances; these would be detected by solution in spirit of wine, as well as by the microscope.
Allied Substances.
Styrax Calamita (Storax en pain Guibourt)—The substance that now bears this name is by no means the Styrax Calamita of ancient times, but is an artificial compound made by mixing the residual Liquidambar bark called Cortex Thymiamatis (p. 273), coarsely powdered, with Liquid Storax in the proportions of 3 to 2. It is at first a clammy mass, acquiring after a few weeks an appearance of mouldiness, due to minute silky crystals of styracin. It is usually imported in wooden drums, and has a very sweet smell. When the bark is scarce, common sawdust is substituted for it, while qualities still inferior are made up with the help of olibanum, honey, and earthy substances. This drug is manufactured at Trieste, Venice and Marseilles.
Several other odoriferous compounds, of which Liquid Storax appears to be the chief ingredient, are made in the East and may still be found in old drug warehouses.[1052]
Resin of Styrax officinalis L.; True Storax—This was a solid resin somewhat resembling benzoin, of fragrant, balsamic odour, held in great estimation from the time of Dioscorides and Pliny down to the close of the last century. It was perhaps the “storace odorifero” exported in the 12th century from Pantellaria[1053] and Sicily. The drug was obtained from the stem of Styrax officinalis L. (Styraceæ), a native of Greece, Asia Minor and Syria, now found also in Italy and Southern France. This plant when permitted to grow freely for several years, forms a small tree, in which state alone it appears to be capable of affording a fragrant resin. But in most localities it has been reduced by ruthless lopping to a mere bush, the young stems of which yield not a trace of exudation. True storax has thus utterly disappeared.
Professor Krinos of Athens has informed us (1871) that about Adalia on the southern coast of Asia Minor, a sort of solid storax obtained from S. officinalis is still used as incense in the churches and mosques. The specimen of it which he has been good enough to send us, is not however resin, but sawdust; it is of a pale cinnamon-brown, and pleasant balsamic odour. By keeping, it emits an abundance of minute acicular crystals (styracin?). The substance is interesting in connection with the statement of Dioscorides, that the resin of Styrax is adulterated with the sawdust of the tree itself, and the fact that the region where this sawdust is still in use is one of the localities for the drug (Pisidia) which he mentions.
Resin of Liquidambar styraciflua L.—a large and beautiful tree, native of North America from Connecticut and Illinois southward to Mexico and Guatemala. In the United States, where it is called Sweet Gum, the tree yields from natural fissures or by incision, small quantities of a balsamic resin, which is occasionally used for chewing. We have before us an excellent sample of it collected for Messrs. Wallace Brothers of Statesville, N. Carolina.[1054]
In Central America this exudation is far more freely produced; an authentic specimen from Guatemala in our possession is a pale yellow, opaque resin of honey-like consistence, becoming transparent, amber-coloured and brittle by exposure to the air. It has a rather terebinthinous, balsamic odour. In the mouth it softens like benzoin or mastich, and has but little taste. Another specimen also from Guatemala, a thick, fluid oleo-resin, of a golden brown hue, was contributed to the Paris Exhibition in 1878.
The resin of L. styraciflua L. has been ascertained by Procter[1055] to contain cinnamic, but not benzoic acid. Harrison[1056] found it to contain styracin and essential oil (styrol?).
Resin of Liquidambar formosana Hance—This tree, which we suppose may be the Styrax liquida folio minore, which Ray names[1057] as occurring in a collection of plants from Amoy, is a native of Formosa and Southern China, where it affords a dry terebinthinous resin, of agreeable fragrance when heated. Of this resin, which is used by the Chinese, a specimen collected in Formosa by Mr. Swinhoe has been presented to us by Dr. Hooker. A tree figured under the name of Fung-heang in the Pun-tsao[1058] is, we presume, this species.
Resin of Altingia excelsa Noronha (Liquidambar Altingiana Bl.) Rasamala of the Javanese and Malays—The Rasamala is a magnificent tree of the Indian Archipelago, Burma and Assam. In Java it yields by incisions in the trunk an odorous resin, yet only very slowly and in very small quantity; this resin is not, or at least not regularly, collected. In Burma, on the other hand, the tree affords a fragrant balsam, of which according to Waring[1059] there are two varieties, the one pellucid and of a light yellowish colour, obtained by simple incision; the other thick, dark, opaque, and of terebinthinous odour, procured by boring the stem and applying fire around the trunk.