Latex (Aceh) (Dutch: latex, also melksap, “milksap”) was the milky sap tapped from the bark of the Hevea brasiliensis rubber tree in the residency of Atjeh in the early twentieth century, and was the raw material from which the Atjeh rubber industry produced inlandse crêpe sheets, plantation ribbed smoked sheet, and other rubber products. The sap was collected by making a small incision (Dutch: tapsnee) in the bark, allowing the fluid to flow into a cup (Dutch: latexbakje) hung at the base of the cut, and was then either coagulated immediately into sheets or preserved with ammonia (Dutch: ammoniak) for transport as liquid latex to the larger factories of the East Coast. Latex extraction underpinned the rubber industry of Atjeh and provided a valuable export commodity and source of regional prosperity from the 1910s onward.
Tapping technique
Tapping was carried out in the early morning, when the internal pressure of the latex vessels was highest and the sap flowed freely. A skilled tapper (Dutch: tapper) made a single diagonal cut, the so-called bastreepje (small bark strip), descending at an angle of about 30 degrees from the horizontal, using a specially shaped tapping knife (Dutch: tapmes) that removed only a thin shaving of bark — typically one to two millimetres — so as not to damage the underlying cambium. At the lower end of the cut a small metal or bamboo spout (Dutch: tapgootje) directed the milky latex into a porcelain or glass cup (Dutch: latexbakje) hung from a wire hook.
Each cut was reopened the next morning by removing a further thin shaving of bark below the previous day’s cut, the tapping panel (Dutch: tapvlakte) descending down the trunk over the course of several years. A well-managed tree could be tapped for twenty years or more before the panel reached the ground and a new panel was opened on the opposite side of the trunk. The process required careful timing and skill to avoid contamination of the latex with dirt, bark fragments, or the watery serum (Dutch: serum) that separated out on standing.
Plantation and smallholder practice
On the European-managed estates of Langsa and the East Coast of Sumatra — many of them established under the Agrarische Wet 1870 regime of long-lease erfpacht concessions — tapping was performed by trained squads of Javanese and Acehnese contract labourers (Dutch: contractkoelies) supervised by European overseers (Dutch: opperpasars). Latex was collected twice daily and brought to the central factory (Dutch: rubberfabriek) of the estate, where it was filtered, bulked, and either preserved with ammonia for shipment as liquid latex or coagulated with formic acid (Dutch: mierenzuur) into slabs for further processing into ribbed smoked sheet or pale crêpe.
In the smallholder gardens of the Atjeh interior, tapping was carried out by the village men themselves, and the latex was processed in small smoke-houses (Dutch: rookhuizen) into inlandse crêpe sheets. Smallholder latex was typically lower in dry-rubber content (Dutch: droge-stof-gehalte) than estate latex — often 25 per cent versus the 35 to 40 per cent of well-managed estates — because the smallholders tapped immature trees, mixed morning and evening collections, and used less careful tapping techniques. The difference was reflected in the price discount applied to inlandse crêpe on the Singapore and Amsterdam markets.
Economic impact
Latex extraction underpinned the rubber industry in Aceh, providing a valuable export commodity and contributing to regional prosperity from the 1910s onward. The Atjeh and Dependencies residency became one of the leading rubber-producing regions of the Netherlands Indies, and the East Coast plain around Langsa was transformed within a single decade from swamp and secondary forest into a continuous landscape of rubber estates, tappers’ lines and rubber factories. The Atjeh tram and the Gajo Road were both extended in the early twentieth century partly to move latex and sheet rubber to the export ports of Belawan and Sabang.
The Stevenson restriction scheme of the 1920s and the International Rubber Regulation Agreement of 1934 limited both estate and smallholder latex production in the depression years, but the latex trade resumed its expansion after the Second World War and remained the principal export of the Atjeh interior well into the post-independence period. Latex was the central commodity around which the modern economic geography of Atjeh was constructed, and the tapping cut (Dutch: tapsnee) on the bark of the Hevea tree remains the most characteristic visual feature of the Atjeh rural landscape.
See Also
- Rubber Industry in Atjeh
- Inlandse Crêpe (Rubber Sheet)
- Gouvernement Atjeh en Onderhoorigheden
- Langsa
- Oostkust van Sumatra
- Belawan
- Sabang
- Atjehsche Staatsspoorwegen
- Gajoweg
- Agrarische Wet 1870
- 1910
- 1920
- 1934
Source
DLP-84-Atjeh.pdf, pp. 14-15.