460 REPORT OF NATIONAL MUSEUM, 1899. 



this gum as a product of trees of the same species as those at present 

 produciiio- the raw gum called Iw the natives and Arabs sandarusiza 

 miti or chakazi; that is, the Trachylohium. inozamhicenM Peters. The 

 gum when dug from the soil has superficially a peculiar pebbled ap- 

 pearance, best described as "goose skin" (Specimens Nos. 02-1:72, 62473, 

 U.S.N.M.), and which Burton considered as due to the impress of the 

 sandy grains in which it had been buried, but which Dr. Kirk regards 

 as due to the structure of the cellular tissues of the tree. The copal 

 when dug up has, according to this authority, exteriorly no trace of 

 the loose skin structure. 



As is the case with the New Zealand and West African gums, the 

 methods of digging are very crude, careless, and desultory. The 

 diggings are mostly beyond the jurisdiction of Zanzibar, but as this is 

 the principal port, most of the material is known commercially as 

 Zanzibar copal. 



BIBLIOGRAPHY. 



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London, India Museum, 1874, pp. 98-103. 

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Report of the Tenth Census of the United States, X, 1880. 

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 to date of publication. 

 G. W. Griffin The Kauri Gum of New Zealand. 



U. S. Consular Reports, II, 1881, p. 241. 

 R. W. Raymond. The Natural Coke of Chesterfield County, Virginia. 



Transactions of the American Institute of Mining Engineers, XI, 1882, p. 446. 

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American Journal of Science, XXIV, 1882, p. 171. 

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American Journal of Science, XXVIII, 1884, p. 105. 

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Eighth Annual Report U. S. Geological Survey, Pt. 2, 1886-87, pp. 483-662. 

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