In 1817, the British began to sell a narcotic drug, Indian opium, to China as a way to reduce the trade deficit and to make the Indian colony profitable. The Qing Administration originally tolerated opium importation because it created an indirect tax on Chinese subjects, while allowing the British to double tea exports from China to England. However, by 1820 the planting of tea in the Indian and African colonies, along with accelerated opium consumption, reversed the flow of silver, and the drug had poisoned thousands of Chinese civilians.