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The terms "cash" or "le" were documented to have been used by British explorers in the 1830s when trading in Qing territories of China.
Under the Hong Kong statute of the Weights and Measures Ordinance, 1 cash is about 0.0013 ounces (0.037 g). Currently, it is 1⁄10 candareen or 1⁄16000 catty, namely 37.79936375 milligrams (0.5833333269 gr).
Roberts, Edmund (1837) . "Chapter X. Weights and Measures". Embassy to the Eastern courts of Cochin-China, Siam, and Muscat : in the U. S. sloop-of-war Peacock during the years 1832-3-4. Harper & brothers. page 136, image 143. OCLC12212199. Retrieved 5 April 2013. The highest weight used in reckoning money, is tael, (leang,) which is divided into mace, (tseen,) candareens, (fun,) and cash, (le.) The relative value of these terms, both among the Chinese, and in foreign money, can be seen by the following table. It should be observed here, that these terms, taels, mace, candareens, cash, peculs, and catties, covids, punts, &;c., are not Chinese words, and are never used by the Chinese among themselves; and, the reason of their employment by foreigners, instead of the legitimate terms, is difficult to conjecture.
This article incorporates text from this source, which is in the public domain. Country Studies. Federal Research Division.