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Unformatted text preview: sten wooden tubes. Pressure on the bottle sends the liquid squirting out of the tube, so they resemble syringes." Evidently the samples filled no Evidently the samples filled no important need at the time, for we hear no more of the gum until thirty­four years afterward. Then, so an English writer tells us, a use was found for the gum­­and a name. A stationer accidentally discovered that it would erase pencil marks. And, as it came from the Indies and was rubbed, it became known as "India rubber." In the mid­19th century rubber was a novelty material, In the mid­19th century rubber was a noveltymaterial, but it did not find much application in the industrial world. It was used first as erasers, and then as medical devices for connecting tubes and for inhaling medicinal gases. With the discovery that rubber was soluble in ether, it found applications in waterproof coatings, notably for shoes and soon after this, the rubberized Mackintosh coat became very popular. Nevertheless, most of these applications were in small volumes and the material did not last long. The reason for this lack of serious applications was the fact that the material was not durable, was sticky and often rotted and smelled bad because it remained in its uncured state. About 1820 American merchantmen, plying between About 1820 American merchantmen, plying between Brazil and New England, sometimes carried rubber as ballast on the home voyage and dumped it on the wharves at Boston. One of the shipmasters exhibited to his friends a pair of native shoes fancifully gilded. Another, with more foresight, brought home five hundred pairs and offered them for sale. They were thick, clumsily shaped, and heavy, but they sold. There was a demand for more. In a few years half a million pairs were being imported annually. New England manufacturers bid against one another along the wharves for the gum which had been used as ballast and began to make rubber shoes. The Pará rubber tree (Hevea brasiliensis) is The often simply called rubber tree. It is of major economic importance because its sap­like extract (known as latex) can be collected and is the primary source of natural rubber. The Pará rubber tree initially grew only in the Amazon rainforest. Increasing demand and the discovery of the vulcanization procedure in 1839 led to a boom in that region, enriching the cities of Manauus and Belem. The name of the tree derives from Pará, the Brazilian state that contains Belém. There had been an attempt made, in 1873, to There had been an attempt made, in 1873, to grow rubber outside Brazil. After some effort, twelve seedlings were germinated at the Royal Botanic Gardens at Kew. These were sent to India for cultivation, but died. A second attempt was then made, some 70,000 seeds being sent to Kew in 1875. About 4% of these germinated, and in 1876 about 2000 seedlin...
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