The British insisted on farmers growing opium in India to balance their trade with China. Tea became extremely popular in England, and by 1830, over 30 million pounds of tea was being imported from China. The British could buy tea from China only by paying in bullion. Hence, there was nothing that England could offer to the Chinese in exchange for tea, except money. Opium was used in Chinese medicine, but was banned for use due to its addictive qualities. The British started an illegal opium trade, and by 1839, there were an estimated 12 million opium smokers in China. All the supplied opium came from India and it formed an easy, cheap way to pay for the tea imported from China.