...
Prior to the 1830s, there was but one port open to Western merchants, Guangzhou (Canton) and but one commodity that the Chinese would accept in trade, silver. British and American merchants, anxious to address what they perceived as a
trade imbalance, determined to import the one product that the Chinese did not themselves have but which an ever-increasing number of them wanted: opium. Before 1828, large quantities of the Spanish silver coin, the Carolus, flowed into China in payment for the exotic commodities that Europeans craved; in contrast, in the decade of the 1830s, despite an imperial decree outlawing the export of yellow gold and white silver, "
only $7,303,841 worth of silver was imported, whereas the silver exported was estimated at $26,618, 815 in the foreign silver coin, $25,548,205 in sycee, and $3,616,996 in gold" (Kuo, p. 51). although the Chinese imperial governed had long prohibited the drug except for medicinal use, the "British Hong" (companies such as Dent, Jardine, and Matheson authorized to operate in Canton) bought cheaply produced opium in the Begal and Malwa (princely) districts under the auspices of the
British East India Company 
, the number 150 lb. chests of the narcotic being imported rising from 9,708 in 1820 to 35,445 in 1835. With the British government's 1833 cancellation of the trade monopoly enjoyed by the East India Company, cheap opium flooded the market, and
China's net outflow of silver amounted to some 34 million Mexican silver dollars over the course of the 1830s.
England and China: The Opium Wars, 1839-60
