Gutta percha and cauchu

Let us begin with gutta percha, because it was in practical use before rubber was.  This came from the sap of an Asian tree that could be tapped, much as the rubber tree (and rubber is the cauchu we will come to later).

In 1832, Dr William Montgomerie saw gutta percha being used to make handles for parangs (machete-like knives) in Singapore. He introduced gutta percha to Europe in 1843, where it was used first for knife handles and in golf balls. In 1845, Werner Siemens suggested using it to insulate telegraph wires, the method was patented in 1847, and the first recorded use of the new insulated wires was in 1849.

In 1848, Michael Faraday was delighted by gutta percha. It could be softened by warming and moulded, but when it cooled, it was flexible and resilient, and it was an insulator. By 1853 in the Gardener’s Chronicle, ‘CRD’ (alias Charles Robert Darwin, a keen reader) was seeking advice on any problems he might expect while using a canvas hose, coated and lined with gutta percha, as a siphon tube to move water from one tank to another on a different level.

After 1855, the Second US Cavalry’s soldiers were issued with a gutta percha talma, a long cape or cloak, extending to the knees, with large loose sleeves. Soldiers in one squadron had gutta percha scabbards and another squadron had gutta percha cartridge boxes, but the material could also serve more peaceful uses. In April, the Portadown Weekly News in Ireland carried an advertisement for “Ladies’ and Children’s Leather and Gutta Percha Boots and Shoes”.

Across the Atlantic, an enterprising American was making waterproof packing paper by giving paper a thin coating of gutta percha dissolved in turpentine. Two New Yorkers, Johns and Crosby, offered a cement for roofing based on gutta percha: the advertised cost was “5 cents a foot”. It was guaranteed for five years.

With steamers entering the Amazon, rubber traders were already moving up the river by 1853, so the era of gutta percha would be brief. Critics sniped, suggesting it cracked, that the failure of the covering had destroyed the second Atlantic cable. Manufacturers of gutta percha cables disagreed, but they still lost out in the end to rubber, and just in time, because the jungles of the East Indies were almost cleared of gutta percha trees by 1859.

A few niche markets were left to gutta percha. Even today, when you have root canal therapy, your dentist may insert a temporary gutta percha filling, but a surgeon on the Australian goldfields in the 1850s was well aware that gutta percha could be softened again.

He told a fellow surgeon he had paid five shillings for a bunch of old tools being sold with a gutta percha bucket, just to acquire the bucket. With this and a supply of hot water, he had ‘stopped’ (filled the cavities in) hundreds of teeth at a guinea a piece, and he expected to stop thousands more before the old bucket was used up. He claimed he was known as an unrivalled dentist, with people coming from far and near.

India rubber, alias cauchu, caoutchouc or gum elastic, was interesting stuff. It was used by the Mesoamericans before Columbus and the Spaniards who followed him must have seen games played with balls made of rubber, but the material did not interest the Europeans as much as gold and silver.

By the 1830s, the needs of industry were changing. Slow steam engines could use oiled leather to seal valves, and while shoes and inflatable canvas boats could be made with India rubber, steam valves could not. Inventors everywhere hunted for ways of making India rubber stronger, tougher and more weather-proof.

One of them was a bankrupt called Charles Goodyear (1800–1860), who had been mixing gum elastic with white lead and sulfur, but the mix was unsuccessful until he had a stroke of luck in February 1839. Some of his gum elastic/sulfur mix landed by accident on a hot pot-bellied stove, and when he scraped the material off, he realized that the heat had produced an elastic rim.

Here was the secret to toughening rubber: mix it with sulfur and heat it. But how much sulfur, and how much heat? In the end, he found that to toughen the rubber, it had to be heated by steam under pressure, providing a temperature of about 270°F (132°C) for several hours.

The molecules of rubber are natural polymers, long chains that can slip and slide past each other. The sulfur forms bridges between chains, tying them together and making a more stable product. At the time, there was no theory to explain this, so anybody seeing the material would have no idea of how the gum elastic had been changed.

Goodyear never benefited from his discovery. He died in 1860, worn out by patent battles and owing some $200,000. The giant Goodyear Tire and Rubber Co. may carry his name, but there is no family connection. It would be some time before rubber tyres would soften the rides of wagons, bicycles and automobiles, but by 1860, railway cars could be fitted with coiled springs, embedded in vulcanized rubber.

People all over the world died as food crops were displaced by rubber plantations, or as Congolese rubber tappers were terrorized, beaten and killed to make them work harder. At the same time, rubber has made our lives better, and it continues to save lives today. Catheters, surgical gloves, condoms and other products are still made of rubber, as are the tires on vehicles and aircraft.

On balance, rubber has probably done more good than harm, just.

Charles Goodyear’s battle to maintain his patent for vulcanised rubber dragged on through 1859. Rubber was beginning to become more popular, and not only in roles filled earlier by gutta percha. Most new uses needed vulcanised rubber, but in 1855, Augustus Gregory experimented with an inflatable boat made of canvas covered with India rubber to explore rivers in northern Australia. It was not a success.

In 1859, a diver crossed the Schuylkill River near Philadelphia, striding along in an India rubber suit that covered him up to his neck, with a sheet-copper helmet over his head. He breathed through a pipe connected to a compressor on a boat and followed a guide rope during his 25-minute stroll. On another front, Messrs Badger and Co reported successfully making a Boehm flute from Goodyear’s vulcanised rubber, though this was probably more like ebonite than the rubber we know today.

Rubber and cotton hoses could stand the pressures being generated by the new steam fire engines– and the late 1850s was a time when fire brigades were being formed in many places and equipping themselves with steam pumps.

Hoses were a major concern, because the high pressures needed tore most cloth, and the available range of hoses was poor. The choice of textiles for any purpose was limited: cotton and wool for everyday use, silk and linen for the rich, and that was about it. Wool sold in New York for 11 to 50 cents a pound, depending on quality. Cotton was plentiful and cost 8.5 to 12.5 cents a pound.

It was a world where anything might find a use,  even isinglass and seahorse teeth.