We have heard that in your own country opium is prohibited with the utmost strictness and severity. (t)his is a strong proof that you know full well how hurtful it is to mankind. since then you do not permit it to injure your own country, you ought not to have the injurious drug transferred to another country, and above all others, how much less to the inner land! of the products which china exports to your foreign countries, there is not one which is not beneficial to mankind in some shape or has ever yet sent forth a noxious article from its soil? not to speak of our tea and rhubarb, things which your foreign countries could not exist a single day without, if we of the central land were to grudge you what is beneficial, and not to compassionate your wants, then wherewithal could you foreigners manage to exist? " - from "letter to queen victoria," (1839) by commissioner lin, chinese trade commissioner for the qing dynasty.