Siam Benzoin.

Botanical name: 

[Kew Bulletin, June and July, 1895.] Benzoin is also known in English commerce as Gum Benjamin. It is a gum resin obtained by incision in the bark of trees in Sumatra and Siam. Benzoin is used as a stimulant and expectorant in chronic bronchitis. It is also one of the principal ingredients in Friar's Balsam, and is largely used for incense. Sumatra benzoin is yielded by Styrax Benzoin, Dry., a well-known tree. Plants of this species are under cultivation at Kew, and many have lately been distributed to botanical establishments in the tropics of the New World. Of the tree yielding Siam benzoin we know very little. As long ago as 1865 Sir R. H. Schomburgk, then British Consul at Bangkok, was asked to investigate the subject, but although able to give, at second hand, a very interesting account of the mode of collecting the resin, he was unable to obtain botanical specimens of the tree yielding it. Of late years renewed efforts have been made to solve the problem.

Captain Hicks, of Bangkok, was successful in obtaining a few small plants of "gum benjamin from the Northern Laos States" in 1882. The survivors of these were presented to the Botanic Gardens at Singapore by Mr. Jamie. A fuller account of Captain Hicks' efforts is given by Mr. E. M. Holmes, F.L.S., in the Pharmaceutical Journal, XIV, 3, p. 355. The locality from which the plants were obtained was given as "Suang Rabang." This we now know is a misprint for Luang Prabang, a district in the extreme northeast of the Shan States of Siam, bordering on Tran Ninh, in the French territory of Anam. In the hope that the Siam benzoin tree might possibly extend to the Shan States of Burma, an application was addressed by Kew to the India Office in 1889, and as a result a careful inquiry was made by the Government of India, in Tennaserim, Upper Burma, and the adjoining Shan States. In 1890 it was reported that "the efforts made to trace the existence of the plant in these localities have been unsuccessful."

Apparently, the first authentic information respecting the district in which the tree is to be found is contained in a recent report by Mr. Beckett, forwarded to the foreign office by Mr. de Bunsen on the Trade of Siam for 1893 (Foreign Office, Annual Series, 1895, No. 1520). The following extract shows that Siam benzoin is obtained from an extremely circumscribed locality on the east bank of the river Mekong, in territory now occupied by the French. It is feared that the trade in this article will be ultimately diverted to Tonquin, which is nearer to the source of supply than Bangkok.

"Of gum benjamin, 319 piculs, or nearly 20 tons, figure in the export list, valued at 21,005 dollars, or 2,713l. This valuable resin is also a product of the east bank of the Mekong, and is interesting as being confined to a narrow zone of forest-clad hill country to the east of Luang Prabang, lying between 19th and 21st degrees of north latitude and longitude east 102 to 105. Some three-fifths finds its way to Bangkok by way of Nan, and the remainder by way of Nongkhai and Korat. The French occupation of Luang Prabang does not seem as yet to have caused any perceptible effect on the Bangkok export of gum benjamin beyond enhancing local prices, but with the completion of new roads, already initiated by the French with a view to speedier communication between Luang Prabang and Tonquin, Bangkok exporters, who are chiefly British, have well-founded fears lest the gum benjamin trade be diverted entirely from Bangkok to Hanoi. The whole of the Bangkok export goes to the London market and thence to France and Belgium, to be manipulated into balsam. A small quantity is used locally for frankincense.

"Prices during 189O were bad, first-class gum benjamin fetching 125 ticals per picul (or about 165l per ton); 45 ticals per picul (about 40l per ton). The good quality known to buyers as 'bold, blocky, almondy,' was scarce." [The remainder of this article is taken from a continuation in the Kew Bulletin for August.]

As the result of independent inquiry made at the instance of Kew by the India Office, the following further information has been received. This was obtained through the Siamese Minister of the Interior at Bangkok. It affords, therefore, an account of Siam benzoin from the purely native point of view. All the accounts agree in ascribing the region of the benzoin trees to the left bank of the Mekong River, in what is now French territory. This is a tract of upland country east and northeast of the important town of Luang Prabang.

India office to Royal Gardens, Kew.
India Office, Whitehall, London, S. W.
July 30, 1895.

Sir:—In continuance of previous correspondence, I am directed by the Secretary of State for India to forward herewith for your information a copy of a letter, and its enclosure, regarding the tree producing Siam benzoin. It is suggested that the memorandum on the Siam benzoin may be found suitable for publication in the Kew Bulletin.

I am, etc.,
(Signed) A. N. Wollaston.
The Director, Royal Gardens, Kew.
Assistant Secretary, Revenue and Statistics Department.
No. 606.—2 F.—7, dated Rangoon, May 30, 1895.

From the Revenue Secretary to the Chief Commissioner of Burma.

To the Secretary to the Government of India, Revenue and Agricultural Department.

With reference to the correspondence concerning the steps taken with the view of identifying the plant or tree which produces the resin known as "Siam benzoin," I am directed to submit, for the information of the Government of India, a copy of a memorandum regarding the tree that produces this resin, and on the gum benjamin industry in Siam, prepared in Bangkok under the orders of the Siamese Minister of the Interior, and forwarded to the Chief Commissioner by Mr. J. G. Scott, in April, 1894. * * *

Mr. Scott stated that the area in which the gum benjamin trees were found was said to be all on the left bank of the Mekong, and, therefore, in what is now French territory. * * *

Mr. Scott further remarked: "The great Siam benzoin tract is Hna Pan Htang, Ha Htang Hok, the upland country east and northeast of Luang Prabang. * * *

Memorandum Regarding the Tree that Produces Resin, and on the Gum Benjamin Industry in Siam.

The gum benjamin tree is large and tall, and has a heart similar to that of the "teng rang" (a species of Shorea) and "phayom" (a kind of mahogany). In its general character, and in the form of its leaves, it resembles the "takieu" tree (a forest tree of hard wood, used for making dug-out boats). The gum benjamin tree is propagated from the original fruit. This, when fallen and lying upon the ground, takes root and sprouts after the fashion of the "phayom" and "gang" trees. As regards the trunk of the gum benjamin tree, there is no one who uses it. Gum benjamin trees are generally found on elevated ground and do not like the plains country. They grow in isolated patches, like the forests of "teng-rang" and teak. A forest patch of gum benjamin usually contains from fifty to sixty trees and upwards, and the tree is found generally in large numbers along the high hills in the extensive forest region of Slua Phan, Tangslok, and the borders of Muang Theng in the province of Luang Prabang. It is rarely met with in other countries, except those outside the provinces immediately contiguous to Siam. The Siamese Thai, Annamites and Tongsoos, who have settled in the above-mentioned provinces, have worked out and traded in the gum benjamin from an early period for successive generations, and these are scattered amongst the neighboring people, as well as being frequently found in Siam also. The season for working the gum benjamin is from the eighth or ninth months (July and August) to the tenth and twelfth months (September and November), when the season ends. Thenceforward is the period during which the gum benjamin is bought and sold. The gum benjamin is worked after the following methods: So many trees are notched, so as to form a girdle around the stem. An interval of three months is allowed to elapse between the period of notching and that of picking the gum benjamin dammar, which wells out of the trunk and collects in the notches. By means of a sharpened stick or the point of a knife this is picked out, bark and all, and gathered at once in baskets. It is then sorted and divided into different classes, according to choice. Picking cannot commence before the interval of three months has elapsed, as the dammar that has trickled out into the notches would not have had time to harden. It would still be soft and sticky, and if picked at the time would become dirty, owing to the bark coming off with it; nor would it be of such value either, as, being sticky, it would cling to other things and the full benefit would not be derived, such as would be the case if it were properly dry. For this reason the gum benjamin must be left for three months after the notching, in order that all the gum possible may well out, and it may become dry and hard. Among the people above-mentioned the picking and sale of gum benjamin is generally considered as one way of obtaining a livelihood, for the gum has a value and is reckoned as a marketable commodity. And even if the people have no other occupation than selling gum benjamin, that by itself is sufficient as a means of livelihood. The period during which the gum benjamin is sold is not necessarily confined to the eighth or ninth months. The reason for selecting that season is because the people of those parts have many other things to do; for instance, they have to plow the fields and reap their rice harvest. In the eighth and ninth months their work on the paddy fields is finished, and they can therefore turn their attention to gum benjamin. For this reason there is a special season. Their paddy fields are their first care, and then the gum benjamin trade. Those who have no business with plowing paddy fields and planting rice can, if they wish, work continuously at gum benjamin, at all seasons and during every month of the year. The gum benjamin trade requires no very great outlay of capital. All the implements required are one large axe, a rice basket and an open woven basket. If a person wishes to work alone, without servants to assist him, he can do so; for in the first stages there is nothing much that requires to be lifted or carried.

The only labor necessary would be when the gum benjamin is being picked and placed in baskets, and has to be carried to the temporary or permanent home of the picker. The profits gained on any one particular occasion or another can hardly be gauged accurately. Those who work out much sell at a large profit; those who work out little sell at smaller profit. One catty (133 ⅓ pounds) and upwards would be considered a large output. Picked gum benjamin is sorted into three classes. The best class, and that which fetches a high price, is called "slua," and is that which is sold in large lumps, and is not dirtied by the presence of bark. The second class is that left over from the first class, and is in somewhat smaller lumps than the latter, and has some, but not much, bark attached to it. This is inferior in quality to Class I, and is half the value. That is to say, if Class I is sold at 75 ticals, Class II would sell at 37 ½ ticals. The third class is that left over from Class II. This class has bark attached to it, is soiled with dust and dirt, and is in small, fine pieces. It is called "mun," and is half the value of Class II. The price of gum benjamin, as sold in the jungle districts where the gum is worked, is as follows: Class I, one Chinese catty (66 ⅔ pounds), 100 or about 75 ticals. Class II, half the price of Class I. Class III, half the price of Class II. The price in Bangkok is: Class I, one Chinese catty, 260 ticals, as it has always been.

The gum benjamin trees that grow in the jungle districts referred to are not the subject of disputed ownership by one person more than another. Any one who wishes to work gum benjamin has merely to go into the jungle, search for and notch as many trees as he pleases, like people, for example, who go into the jungle to cut posts for their houses. Nor is there any tax or other emolument accruing to the country from either the trunk or the gum of the gum benjamin tree; nor is the gum benjamin trade one in the prosecution of which much thieving or fighting arises, whether it is because there are many people together at a time, or because, being in the jungle where there are fierce tigers, one man cannot steal along alone by himself, but is obliged to travel with parties, and so robbery and theft are rendered impossible, is uncertain. This gum is sweet-scented, and is much used in mixing either with medicines or scents of various kinds. For whichever of these purposes it is sold, it always fetches a high price, like other valuable commodities, and for that reason gum benjamin is an article of commerce which merchants have bought and sold from time immemorial to the present day.


The American Journal of Pharmacy, Vol. 67, 1895, was edited by Henry Trimble.