Canton System
In the 18th century the demand for Chinese luxury goods (particularly silk, porcelain, and tea) created a trade imbalance between China and Britain. European silver flowed into China through the Canton System, which confined incoming foreign trade to the southern port city of Canton. To counter this imbalance, the British East India Company began to grow opium in Bengal and allowed private British merchants to sell opium to Chinese smugglers for illegal sale in China. The influx of narcotics reversed the Chinese trade surplus, drained the economy of silver, and increased the numbers of opium addicts inside the country, outcomes that seriously worried Chinese officials.