The Gutta Percha and Rubber of the Philippine Islands

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Bureau of Public Print., 1903 - Gutta-percha - 43 pages
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Page 28 - Obach (23) gives a tensile strength of 5,000 pounds for the best gutta percha while for the gutta from it he found about 6,500, which closely corresponds to results given above. This also brings out most clearly the excellent quality of the best Philippine gutta percha. The results of the combined chemical and physical tests on various samples of so-called "guttas...
Page 19 - Tawi-Tawi can not stand this for any length of time and already the gutta percha trees have entirely disappeared from the vicinity of the coast regions and of the large rivers. According to the forest surveys made so far in the Islands the average number of trees of 1 foot in diameter is between forty and fifty per acre, and considering the large number of species found in the forests the number of trees of any one species is generally placed at four or five. With this liberal allowance the forest...
Page 30 - As neither direct slipping nor grafting has ever succeeded with gutta percha trees, the method called marcottage was tried in Java and the Malay States with some success. This consists in selecting a young straight limb from a large tree and at the point where the roots are to grow the bark is removed for the length of an inch around the entire limb. The denuded spot is then packed with rich mud, which is held in by a coating of cocoanut or other fiber.
Page 34 - The resulting gutta can be further purified by redissolving in distilled gasoline and reprecipitating. The filtrate containing the dissolved resins is redistilled and the recovered gasoline used for effecting further solution of gutta-percha, thus making the process continuous. The gutta so secured, on being warmed, can be pressed into any desired form for experimentation. The gutta used in the above experiments was so prepared, and the results of the physical and chemical tests showed it to be unaffected...
Page 30 - ... light shade (English method). By the Dutch method a light shade is required around each seedling until a vigorous growth is secured. The seedlings are set out about 5 by 5 yards apart, though where it is desired to obtain the largest amount of leaves per acre the space allotted is 4 by 4 yards. No special care seems necessary except to keep them free from weeds. Too much stress, however, can not be laid on the care which should be taken not to break or injure the long tap root of the young plant...
Page 19 - ... has a market value. The English had the true idea when they took away its market value through prohibiting exportation. The only trouble was that the Malay States are on a peninsula and not an island. This law, if applied to the Philippines, might succeed better by reason of their geographical situation, but so far nothing of this kind has been tried here. As soon as the forestry bureau was established in 1899, the felling of...
Page 7 - INTRODUCTION. The material for this bulletin was collected under the direction of the Bureau of Forestry and of the Bureau of Government Laboratories. As early as 1900 the attention of the Government was called to the fact that many of the wild tribes in the southern islands were engaged in cutting down large numbers of forest trees in order to secure the gutta percha and rubber which they contained.
Page 40 - Chemically then, there appears to be only one rubber, while physically certain differences are to be found between samples from different species. Whether the superiority of Para rubber is due, therefore, to the excellency of the rubber itself or to the above-mentioned method of coagulation has not yet been determined. However, it is a fact that Para rubber from the tree species Hevea brasiliensis Muell.
Page 28 - As soon as the native collectors made such heavy inroads on gutta-percha forests as to make certain of their serious decimation if not entire destruction, the various governments having tropical possessions in the East began to take note and make inquiries but it was not until the last four or five years that the notes became serious or the inquiries anxious. Both explorations and inquiries revealed that the greater part of the Malay Peninsula had lost most of its trees, and that the portions of...
Page 33 - The principal gutta-percha plantations now under cultivation and in which much useful and desired experimenting is being done, are located at Tjipitir and Buitenzorg in Java, on Rhio Island at Singapore, and Bukit Timah on Singapore Island, on Penang Island, and at one or two places in the Federated Malay States. Enough time and work have been spent to demonstrate most conclusively that...

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