How Much Opium was Imported Into China Before 1840?
840年前输入中国的鸦片数量

Hew much opium was imported into China before 1840? This question is generally answered by citing the tables in H. B. Morse's The International Relations of the Chinese Empire. But there are many mistakes in H. B. Morse's well-known book. According to my studies, the total importation of opium into China before 1840 is about 400,000 chests, which is roughly worth 200 million taels of silver; the annual drain of silver is no more than 5 to 6 million taels; and the annual opium smokers prior to 1840 is about 2.5 million.