Reports by the juries. Class IV. Animal and vegetable substances chiefly used in manufactures, as implements, or for ornaments / Richard Owen, Edward Solly, reporters.

  • Owen, Richard, Sir, 1804-1892.
Date:
[1851]
Catalogue details

Licence: Public Domain Mark

Credit: Reports by the juries. Class IV. Animal and vegetable substances chiefly used in manufactures, as implements, or for ornaments / Richard Owen, Edward Solly, reporters. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    unfortunate “ tackiness,” which so greatly diminishes the value of some forms of India-rubber. The samples from Assam, in ]iarticular, illustrate the great importance of care and attention in the preparation of caoutchouc ; the specimens sent over some years since by Capt. Veitch are of excellent quality, and have not undergone any change since they have been in England. They were evidently formed from many successive layers of sap, each layer being allowed to dry before a fresh one was applied. On the other hand, many of the more recent specimens are sticky and in a partially decomposing state. These have plainly been formed by the coagulation of a considerable bulk of the sap rapidly collected ; a little time and attention have thus been saved, but at the sacrifice of the most useful properties of the caoutchouc. All samples of India-rubber from new localities, where there is any probability of a large quantity being obtained, are valuable. In connection with these specimens, particular attention should be drawn to the Cuttemundoo, or Kattimundoo, a highly-interesting substance exhibited from Viza- gapatam by Mr. W. Elliot, and obtained from the Akoo Chenroodoo, or Bramha Chemoodoo, the Euphorbia antiquorum of Koxburgh. It is of a dark-brown colour, opaque except in thin pieces, is hard and somewhat brittle at common temperatures, but easily softened by heat; in boiling water it is perfectly insoluble, but it becomes soft, viscid, and remarkably sticky and adhesive, like bird-lime : as it cools it reassumes its original character. Heated, it melts and burns with a bright and smoky flame, at the same time giving out a peculiar odour, somewhat resembling that of burning caoutchouc or gutta percha. This remarkable substance appears to be a hydro-carbon, closely resembling caoutchouc and gutta percha in chemical composition, but considerably different from both in physical characters. It is said to be used as a cement for joining metal, fastening knife-handles, &c.; and there is little doubt that it might be advantageously employed for a great number of purposes in the arts. Cutte- mundoo merits a minute and careful examination; it promises to prove a valuable addition to the India-rubber series; and the Jury have accordingly awarded a Prize Medal to Mr. Elliot for its introduction. Excellent samples of the different forms of caoutchouc usually met with in com- merce are shown by Lockixgton, Bunn, and Co. (Class XXVIII. 77); and some fine specimens of gutta-percha, both in its rough state as imported and also in the various stages through which it passes in the process of purification, are exhibited by the Gutta Percha Company (Class XXVIII. 85); both these series of specimens, however, are merely shown in illustration of the various uses to which these substances are applied. The sample of dragon’s-blood from Sumatra, called Heraduccun, being of superior quality, was deemed worthy of Honourable Mention. Amongst the other collections of gums and resins, the specimens shown by J. Loch, Esq., and contributed by His Highness the Rajah of Travancore, are considered worthy of Honourable Mention. Besides these, the turpentine from Churra Poonjee, in the Dacca division ; the Bombax resin ; the Saul gum, from the Shorea robusta, from Beerbhoom and from Bhaugulpore; the Theetske resin, from Arracan; the Kerelu resin, from Assam, contributed by Major Hannay ; the Dammar, from Malacca, Sumatra, Java, and other places deserve notice. VoL. I. 2 A