Gutta percha

Background

Gutta percha is a gum resin obtained from trees of the Sapotaceae family. It is a natural plastic that is pliable in hot water, but inelastic in ordinary conditions. Once prized for electrical insulation and almost as ubiquitous as its close cousin rubber, gutta percha was once widely used for domestic, medical and industrial purposes, particularly for submarine electric telegraph cables in the mid-19th century. It subsequently became a largely forgotten commodity as a result of modern substitutes such as plastic and similar synthetics.¹

Origins and distribution
Gutta percha is a name derived from two Malay words, getah and pertja. Getah means sticky gum, while pertja is the name of a less valuable gutta tree. The term “gutta percha” may therefore be a corruption of the original native names.²

In Malaya, there are over 100 species of trees belonging to the Sapotaceae family, and all of them produce gutta percha. In most cases, however, gutta percha is mixed with various resinous substances and is therefore of too little value to be worth collecting. The trees are natural inhabitants of Southeast Asia, particularly in Malaysia and Indonesia. A few species, mainly the genera Palaquium and Payena, have gutta present in sufficient amounts to be of commercial importance. The best grade of gutta percha is produced by Palaquium gutta, also known as Isonandra gutta or getah taban merah, in the Malay Peninsula.³

Gutta percha was discovered in Singapore when William Montgomerie, a British surgeon of the East India Company, first noticed it in 1822. He noticed that the gum from gutta percha trees was used by native woodsmen to make handles for parang, a type of machete or cleaver. He then experimented on the material and, in 1842, recommended it to the Medical Board in Calcutta as a substance for making surgical splints. Montgomerie also sent samples to the Society of Arts in London, which were well received, thereby introducing gutta percha to the Western world. The society awarded him a gold medal in 1844. An earlier introduction of the material to Europe had taken place in 1656 when Englishman John Tradescant brought it there and described it as “pliable mazer wood”, but it remained a curiosity for many years.⁴

Description
Gutta percha is a hard, dark substance at normal atmospheric temperatures. Chemically, it is a stereoisomer of rubber, sharing a similar chemical composition – polyisoprene. Unlike its elastic cousin, it will not bounce when dropped, or stretch and return to its original shape and size. It is very dense and watertight, more so than rubber. It is gum plastic rather than gum elastic.⁵

The Isonandra gutta is an impressive tree, growing to between 60 and 80 ft in height, with a trunk diameter of between 2 and 5 ft, and a great buttress root system rising up to 15 ft off the ground. When grown in the open, the tree branches are low. The leaves are simple, alternate, and crowded together towards the end of the twigs. Isonandra gutta trees do not naturally form pure forests, but are accompanied by a large number of other kinds of trees, many of them larger in size. They can be propagated from cuttings and marcots.⁶

Usage⁷
The gutta percha samples Montgomerie sent to London were displayed at the Society of Arts. Subsequently, small quantities of the material were shipped from Singapore to London. British manufacturers of India rubber goods began to offer moulded gutta percha items such as boot soles, pump buckets and bottle stoppers. Soon after, gutta percha caught the attention of Michael Faraday, an English scientist best known for his discovery of electromagnetic induction. In 1848, Faraday wrote about the uses of gutta percha as an electrical insulator in The Philosophical Magazine. Word of the material spread among British telegraphers, who used it to insulate wires for underground telegraph lines and found it to be far superior to anything they had tried before.

It was in submarine telegraphy that gutta percha came into its own in terms of mass industrial use. At the time, there were plans for underwater cables to be laid across rivers and seas, particularly in the English Channel, but none of the then available insulating materials had worked well. In gutta percha, engineers found an insulator that could be moulded like rubber but unlike rubber, would not crumble underwater. Before long, risk-taking entrepreneurs were seeking to profit from underwater cables coated with gutta percha.

In September 1851, the first successful cable was laid by brothers, Jacob and John Watkins Brett, between England and France. The cable connected Dover and Calais over 25 nautical miles and marked the start of a boom in submarine telegraphy that would last well into the next century. The submarine cables laid globally grew from about 15,000 nautical miles in 1866 to over 200,000 nautical miles by 1900. Insulated by a sheath of gutta percha, this global cable network was often referred to in the 19th century as the “nervous system” of the British Empire and of world commerce, as it constituted a key means by which modern technology extended its reach around the world. No better material had been found for this purpose until polythen was discovered in the 1930s.

Today, gutta percha is used mainly to cover golf balls and in dental work as a filling material in root canal treatment.



Authors
Naidu Ratnala Thulaja & Nor-Afidah A Rahman



References
1. John Tully, The Devil’s Milk: A Social History of Rubber (New York: Monthly Review Press, 2011), 17, 21, 123–29 (Call no. RBUS 338.47678209 TUL); R. Prakash, V. Gopikrishna and D. Kandaswamy, “Gutta Percha – An Untold Story,” Endodontology, 17, no. 2 (December 2005): 32–36; British Empire Exhibition, Pamphlets: Malayan Series, Gutta Percha (Singapore: Fraser and Neave, 1923), 1–4. (Call no. RCLOS 959.5 BRI-[RFL])
2. Tully, Devil’s Milk, 17, 21, 123–29; Prakash, Gopikrishna and Kandaswamy, “Gutta Percha,” 32–36; British Empire Exhibition, Pamphlets, 1–4.
3. Tully, Devil’s Milk, 17, 21, 123–129; Prakash, Gopikrishna and Kandaswamy, “Gutta Percha,” 32–36; British Empire Exhibition, Pamphlets, 1–4.
4. “The Discovery of Gutta Percha in Singapore,” Straits Times, 10 March 1884, 3 (From NewspaperSG); “William Montgomerie,” The Plastics Historical Society, accessed 17 June 2019; Tully, Devil’s Milk, 123–29; Prakash, Gopikrishna and Kandaswamy, “Gutta Percha,” 32–36.
5. Tully, Devil’s Milk, 124.
6. Tully, Devil’s Milk, 126; British Empire Exhibition, Pamphlets, 2–3, 7.
7. Bruce J. Hunt, “Insulation for an Empire: Gutta-Percha and the Development of Electrical Measurement in Victorian Britain” in Semaphores to Short Waves, ed., Frank A.J.L. James (London: Royal Society of Arts, 1998), 85–100; Joon Ian Wong, “The Story of the Humble Latex, Which Laid the Foundation for the Global Web,” 5 October 2016; The Plastics Historical Society, “William Montgomerie.”



The information in this article is valid as at June 2019 and correct as far as we can ascertain from our sources. It is not intended to be an exhaustive or complete history of the subject. Please contact the Library for further reading materials on the topic.