Gutta-producing trees
L. Wray, a scientific assistant in the Perak State Service, published this botanical and economic survey of gutta-percha producing trees in 1883, prefaced by an introduction from Hugh Low, the British Resident of Perak. Set against the backdrop of rapidly declining gutta exports from the Perak River valley, the article’s central thesis is that the traditional Malay method of collecting gutta by scoring the bark of felled trees wastes the overwhelming majority of the product, which remains locked in the discarded bark, and that a simple process of maceration could recover it at a fraction of the current cost in tree destruction.
Summary
The article serves a dual purpose: it provides detailed botanical descriptions of the various species of gutta-producing trees found in Perak—primarily members of Dichopsis (or Isonandra), Payena, and Bassia—and it presents the results of Wray’s experimental investigation into the efficiency of the prevailing collection method. Wray documents the morphological characteristics, habitat preferences, flowering and fruiting seasons, and commercial qualities of each variety, noting that the trees are slow-growing and that the central parts of the Peninsula, with their light sandy soils over metamorphic rocks, do not support them at all, while the clayey loams over granite near the coasts and mountain ranges are their true domain.
The historical problem driving the investigation was the visible depletion of mature gutta trees in Perak, which had reached a point where Hugh Low advised the state government in 1880 to forbid export altogether as the only means of preventing the annihilation of the species. Wray’s experiments, conducted in May and August 1883, demonstrated that the bark stripped from felled trees and left to rot in the jungle contained a substantial reserve of gutta that could be extracted by pounding or rasping the bark and boiling it in water, or by solvent extraction with chloroform. His calculations showed that the traditional method recovered only a small fraction of the total gutta content of a tree, leading him to estimate that the same commercial supply could be sustained with a tiny proportion of the current annual destruction of trees.
The article also addresses the practical question of whether bark could be profitably exported for processing, and identifies Payena Leerii (Getah Sundik) as the most promising candidate for plantation cultivation on coastal swamps, noting that it fruits freely, grows fast, and produces hard timber as a secondary product.
Key Findings
- A Dichopsis Gutta tree two feet in diameter and over one hundred years old yielded only 2 lb 5 oz of gutta by the traditional scoring method, valued at 7s. 6d. (p. 212).
- Wray’s experiments on Getah Taban Simpor bark showed that wet bark contained 5.3–5.7 per cent of its weight in gutta (11.4 per cent when dried), recoverable by pounding and boiling or chloroform extraction (pp. 218–219).
- For every pound of gutta collected by the traditional method, approximately 37 pounds were wasted in the bark left to rot in the jungle (p. 219).
- Accepting the Kew Report’s 1875 estimate of 10 million pounds of gutta exported from the Straits Settlements, Wray calculated that 300 million pounds—worth £37,500,000 at 2s. 6d. per pound—were destroyed in that single year alone (pp. 219–220).
- Payena Leerii (Getah Sundik) was identified as the most suitable species for government plantation on coastal swamp lands, being fast-growing, free-fruiting, and producing hard, close-grained timber (p. 221).
- Gutta trees are absent from the light sandy soils of Upper Perak (over slates and schists) but thrive on clayey loam over granite in the moist coastal and mountain ranges near the Straits of Malacca (p. 209).
Conclusion
Wray’s definitive historical takeaway is that the existing mode of gutta collection is so fundamentally wasteful that it constitutes an act of economic and ecological self-destruction: the same supply of gutta-percha could be furnished with one-thirtieth of the present annual destruction of trees, and without immediate reform the species faces annihilation in the regions where it is currently exploited.
Context
- The article was submitted to the Society through Sir Frederick A. Weld at the request of Hugh Low, the British Resident of Perak, and reflects the colonial administrative practice of commissioning scientific surveys to support resource management decisions (p. 207).
- Wray’s specimens were dispatched to the Royal Gardens at Kew, Calcutta, and Ceylon for botanical identification, illustrating the network of imperial scientific institutions that underpinned colonial natural history in this period (pp. 208, 211).