part 31

(1878).

[356] Quoted by Graham, _Catal. of Bombay Plants_, 1839. 25.

[357] _Pharm. Journ._ xi. (1852) 65.

=Preparation=—The seeds are reniform, somewhat crescent-shaped or oblong, laterally compressed and wrinkled, ⁶/₁₀ to ⁸/₁₀ of an inch long by about ⁴/₁₀ broad. Each seed weighs on an average about eight grains. The thick cotyledons, which are inseparable,[358] have a mild oily taste. Examination under the microscope shows them to be built up of large reticulated cells containing a considerable proportion of crystalline fat readily soluble in benzol. In addition globular masses of albuminous matter occur which with iodine assume a brownish yellow hue. With perchloride of iron the walls strike a greenish-black.

The process followed by the natives of India (by whom alone the oil is prepared) has been thus described:—The seeds having been dried by exposure for some days to the sun are bruised, and boiled in water. The oil collects on the surface, and concretes when cool into a cake which requires to be purified by melting and straining.

=Description=—Kokum Butter is found in the Indian bazaars in the form of egg-shaped or oblong lumps about 4 inches long by 2 inches in diameter, and weighing about a quarter of a pound. It is a whitish substance, at ordinary temperatures, firm, dry, and friable, yet greasy to the touch. Scrapings (which are even pulverulent) when examined in glycerin under the microscope show it to be thoroughly crystalline. They have a mild oily taste, yet redden litmus if moistened with alcohol.

By filtration in a steam-bath, kokum butter is obtained perfectly transparent and of a light straw-colour, concentrating again at 27·5° C. into a white crystalline mass: some crystals appear even at 30°. Melted in a narrow tube, cooled and then warmed in a water bath, the fat begins to melt at 42·5 C., and fuses entirely at 45°. The residue left after filtration of the crude fat is inconsiderable, and consists chiefly of brown tannic matters soluble in spirit of wine.

When kokum butter is long kept it acquires an unpleasant rancid smell and brownish hue, and an efflorescence of shining tufted crystals appears on the surface of the mass.

=Chemical Composition=—Purified kokum butter boiled with caustic soda yields a fine hard soap which, when decomposed with sulphuric acid, affords a crystalline cake of fatty acids weighing as much as the original fat. The acids were again combined with soda and the soap having been decomposed, they were dissolved in alcohol of about 94 per cent. By slow cooling and evaporation crystals were first formed which, when perfectly dried, melted at 69·5° C.: they are consequently _Stearic Acid_. A less considerable amount of crystals which separated subsequently had a fusing point of 55°, and may be referred to _Myristic Acid_.

A portion of the crude fat was heated with oxide of lead and water, and the plumbic compound dried and exhausted with ether, which after evaporation left a very small amount of liquid oil, which we refer to _Oleic Acid_.

Finally the sulphuric acid used at the outset of the experiments was saturated and examined in the usual manner for volatile fatty acids (butyric, valerianic, &c.) but with negative results.

[358] The embryo, according to Bentley and Trimen (_l. c._) consists chiefly of the _thickened_ radicle, and is almost devoid of cotyledons.

The fat of the seeds of _G. indica_ was extracted by ether and examined chemically in 1857 by J. Bouis and d’Oliveira Pimentel.[359] It was obtained to the extent of 30 per cent., was found to fuse at 40° C. and to consist chiefly of stearin (tristearin). The seeds yielded 1·72 per cent. of nitrogen. Their residue after exhaustion by ether afforded to alkaline solutions or alcohol a fine red colour.

=Uses=—The results of the experiments above-noted show that kokum butter is well suited for some pharmaceutical preparations. It might also be advantageously employed in candle-making, as it yields stearic acid more easily and in a purer state than tallow and most other fats. But that it is possible to obtain it in quantities sufficiently large for important industrial uses, appears to us very problematical.

DIPTEROCARPEÆ.

=BALSAMUM DIPTEROCARPI.=

_Balsamun Gurjunæ; Gurjun Balsam, Wood Oil._

=Botanical Origin=—This drug is yielded by several trees of the genus _Dipterocarpus_, namely—

_D. turbinatus_ Gärtn. f. (_D. lævis_ Ham., _D. indicus_ Bedd), a native of Eastern Bengal, Chittagong and Pegu to Singapore, and French Cochin China.

_D. incanus_ Roxb., a tree of Chittagong and Pegu.

_D. alatus_ Roxb., growing in Chittagong, Burma, Tenasserim, the Andaman Islands, Siam, and French Cochin China.

_D. zeylanicus_ Thw. and _D. hispidus_ Thw., indigenous to Ceylon.

_D. crispalatus_ ... abounding, together with _D. turbinatus_ and _D. alatus_, in French Cochin China.

_D. trinervis_ Bl., a native of Java and the Philippines, and _D. gracilis_ Bl., _D. littoralis_ Bl., _D. retusus_ Bl. (_D. Spanoghei_ Bl.), trees of Java supply a similar useful product which as yet appears to be of less commercial importance.[360]

The Gurjun trees are said by Hooker[361] to be among the most magnificent of the forests of Chittagong. They are conspicuous for their gigantic size, and for the straightness and graceful form of their tall unbranched trunk, and small symmetrical crown of broad glossy leaves. Many individuals are upwards of 200 feet high and 15 feet in girth.

=History=—Gurjun balsam was enumerated as one of the productions of Ava by Francklin[362] in 1811, and in 1813 it was briefly noticed by Ainslie.[363] Its botanical origin was first made known by Roxburgh, who also described the method by which it is extracted.

[359] _Comptes Rendus_, xliv. (1857) 1355.

[360] That of _D. trinervis_ is especially used in Java. Filet, _Plantkundig Woordenboek voor Nederlandsch Indië_, Leiden, 1876, No. 6157.

[361] _Himalayan Journal_, ed. 2, ii. (1855) 332.

[362] _Tracts on the Dominions of Ava_, Lond. 1811. 26.

[363] In the _Catalogue des Produits des_ _Colonies françaises, Exposition Universelle de 1878_, p. 175, it is stated that the balsam of _D. alatus_ in French Cochin China is preferred, being a “_huile b’anche_.”

The medicinal properties of Gurjun balsam were pointed out by O’Shaughnessy[364] as entirely analogous to those of copaiba; and his observations were confirmed by many practitioners in India. This has obtained for the drug a place in the _Pharmacopœia of India_ (1868).

=Extraction=—A recent account of the production of this drug is found in the _Reports of the Jury of the Madras Exhibition of 1855_. It is there stated that _Wood Oil_, as the balsam is commonly called, is obtained for the most part from the coast of Burma and the Straits, and is procured by tapping the trees about the end of the dry season. Several deep incisions are made with an axe into the trunk of the tree and a good-sized cavity scooped out. In this, fire is placed, and kept burning until the wood is somewhat scorched, when the balsam begins to exude, and is then led away into a vessel of bamboo. It is afterwards allowed to settle, when a clear liquid separates from a thick portion called the “_guad_.” The oil is extracted year after year, and sometimes there are two or three holes in the same tree. It is produced in extraordinary abundance; from 30 to 40 gallons according to Roxburgh may sometimes be obtained from a single tree in the course of a season, during which it is necessary to remove from time to time the old charred surface of the wood and burn afresh.

If a growing tree is felled and cut into piece, the oleo-resin exudes and concretes on the wood, very much, it is said, _resembling camphor_ (?) and having an aromatic smell.

=Description=—As Gurjun balsam is the produce of different trees as well as of different countries, it is not surprising to find that it varies considerably in its properties.

The following observations refer to a balsam of which 400 lb. were recently imported from Moulmein for a London drug firm. It is a thick and viscid fluid, exhibiting a remarkable fluorescence, so that when seen by reflected light it appears opaque and of dingy greenish grey; yet when placed between the observer and strong daylight it is seen to be perfectly transparent and of a dark reddish-brown.[365] It has a weak aromatic copaiba-like odour and a bitterish aromatic taste without the persistent acridity of copaiba. Its sp. gr. at 16·9° C. is 0·964.

[364] _Mat. Med. of Hindoostan_, Madras, 1813. 186.

[365] _Bengal Dispensatory_, 1842. 22.

With the following liquids Gurjun affords perfectly clear solutions which are more or less fluorescent, namely pure benzol (from benzoate of calcium), cumol, chloroform, sulphide of carbon, essential oils. On the other hand, it is not entirely soluble in methylic, ethylic, or amylic alcohol; in ether, acetic ether, glacial acetic acid, acetone, phenol (carbolic acid), or in caustic potash dissolved in absolute alcohol. Many samples of commercial benzin also are not capable of dissolving the oleo-resin perfectly, but we have not ascertained on what constituent of such benzin this depends. We have further noticed that that portion of petroleum which is known as _Petroleum Ether_, containing the most volatile hydrocarbons, does not wholly dissolve the oleo-resin. One hundred parts of the balsam warmed and shaken with 1000 parts of absolute alcohol yielded on cooling a precipitate of resin amounting when dried to 18·5 parts. All concentrated solutions of the balsam are precipitated by amylic alcohol.

If the balsam is kept for a long time in a stoppered vessel at 100° C. it simply becomes a little turbid; but about 130° C. it is transformed into a jelly, and on cooling does not resume its former fluidity. Balsam of copaiba heated in a closed glass tube to 220° C. does not at all lose its fluidity, whereas Gurjun balsam becomes an almost solid mass.

=Chemical Composition=—Of the balsam 6·99 grammes dissolved in benzol and kept in a water bath until the residue ceased to lose weight, yielded 3·80 grammes of a dry, transparent, semi-fluid resin, corresponding to 54·44 per cent., and 45·56 of volatile matters expelled by evaporation. But another sample afforded us much less residue. By submitting larger quantities of the above balsam to the usual process of distillation with water in a large copper still, 37 per cent. of volatile oil were easily obtained. The water passing over at the same time did not redden litmus paper. A dark, viscid, liquid resin remained in the still.

The essential oil is of a pale straw-colour and less odorous than most other volatile oils. Treated with chloride of calcium and again distilled, it begins to boil at 210° C. and passes over at 255°-260° C., acquiring a somewhat empyreumatic smell and light yellowish tint. The purified oil has a sp. gr. of 0·915;[366] it is but sparingly soluble in absolute alcohol or glacial acetic acid, but mixes readily with amylic alcohol.

According to Werner (1862) this oil has the composition C₂₀H₃₂ like that of copaiba. He says it deviates the ray of polarized light to the left, but that prepared by one of us deviated strongly to the _right_, the residual resin dissolved in benzol being wholly inactive. The oil does not form a crystalline compound with dry hydrochloric acid, which colours it of a beautiful blue.[367] De Vry[368] states that the essential oil after this treatment deviates the ray to the right.

The resin contains, like that of copaiba, a small proportion of a crystallizable acid which may be removed by warming it with ammonia in weak alcohol. That part of the resin which is insoluble even in absolute alcohol,[369] we found to be uncrystallizable. The _Gurgunic Acid_, as the crystallized resinous acid is called by Werner,[370] but which it is more correct to write _Gurjunic_, may consequently be prepared by extracting the resin with alcohol (·838) and mixing the solution with ammonia. From the ammoniacal solution gurjunic acid is precipitated on addition of a mineral acid, and if it is again dissolved in ether and alcohol it may be procured in the form of small crystalline crusts. From the specimen under examination we were not successful in obtaining indubitable crystals.

[366] 0·944 according to Werner; 0·931 O’Shaughnessy; 0·928 De Vry (1857).

[367] This magnificent colouring matter is not dissolved by ether.

[368] _Pharm. Journ._ xvi. (1857) 374.

[369] The sample of gurjun balsam examined by Werner as well as the resin it contained were entirely soluble in boiling potash lye.

[370] Gmelin, _Chemistry_, xvii. 545.

Gurjunic acid, C₄₄H₆₈O₈ according to Werner, melts at 220° C., and concretes again at 180° C.; it begins to boil at 260° C., yet at the same time decomposition takes place. By assigning to this acid the formula C₄₄H₆₄O₅ + 3H₂O, which agrees well with Werner’s analytical results, we may regard it as a hydrate of abietinic acid, the chemical behaviour of which is perfectly analogous. Gurjunic acid is soluble in alcohol 0·838, but not in weak alcohol; it is dissolved also by ether, benzol, or sulphide of carbon (Werner).

In copaiba from Maracaibo, Strauss (1865) discovered _Metacopaivic Acid_ which is probably identical with gurjunic; the former, however, fuses at 206° C.

The amorphous resin forming the chief bulk of the residue of the distillation of the balsam, has not yet been submitted to exact analysis. We find that after complete desiccation it is not soluble in absolute alcohol. A crystallized constituent of Gurjun, which we obtained from a balsam of unknown origin, has been shown[371] to answer to the formula C₂₈H₄₆O₂. Its crystals, belonging to the asymmetric system, melt at 126°-130°C.; they are entirely devoid of acid character. A comparative examination of the product of each of the above named species of Dipterocarpus would be highly desirable.

=Commerce=—Gurjun balsam is exported from Singapore, Moulmein, Akyab and the Malayan Peninsula, and is a common article of trade in Siam. It is likewise produced in Canara in Southern India. It is occasionally shipped to Europe. More than 2000 lb. were offered for sale in London under the name of _East India Balsam Capivi_, 4th October 1855; and in October 1858, a no less quantity than 45 casks appeared in the catalogue of a London drug-broker. It is now not unfrequent in the London drug sales.

=Uses=—In medicine it has hitherto been employed only as a substitute for copaiba, and chiefly in the hospitals of India.

In the East its great use is as a natural varnish, either alone or combined with pigments; and also as a substitute for tar as an application to the seams of boats, and for preserving timber from the attacks of the white ant. To the first application it is often made better appropriated[372] by boiling it, so that the essential oil is evaporated.

_Wood Oil of China_—The oleo-resin of Dipterocarpus must not be confounded with the so-called _Wood Oil_ of China, which is of a totally different nature. The latter is a fatty oil expressed from the seeds of _Aleurites cordata_ Müll. Arg. (_Dryandra cordata_ Thunb. _Elaeococca Vernicia_ Sprgl. Prodromus xv.