The following lectures were given in pursuance of a determination I came to some six years ago in Hong Kong, viz. that if I lived to return to England I should take some steps, either by public lectures or by the publication of a book, to expose the mischievous fallacies disseminated by the “Anglo-Oriental Society for the Suppression of the Opium Trade.” About that time nearly every mail brought out newspapers to China containing reports of meetings held in England condemnatory of the Indo-China opium trade, at which resolutions were made containing the grossest mis-statements and exaggerations as to opium-smoking, and also the most unfounded charges against all parties engaged in the opium trade, showing clearly, to my mind, that not one of the speakers at those meetings really understood the subject he spoke about so fluently. I have now, happily, been able to carry out my intention. Unfortunately, I was deprived of the opportunity of delivering these lectures in Exeter Hall, which was not only more central than St. James’s Hall, but where I could have selected a more convenient hour for the purpose than the only time the Secretary of the latter Company could place at my disposal, the reason being that the Committee of Exeter Hall refused to allow me its use for the purpose of refuting the false and untenable allegations of the Anti-Opium Society, an act of intolerance which I think I am justified in exposing. I trust, however, that any drawback on this account will be compensated for by the publication of the lectures. I am well aware that this volume has many imperfections, but there is one respect in which I cannot reproach myself with having erred, and that is, in having overstepped the bounds of truth. I have the satisfaction of knowing that all I have stated in the lectures is substantially true and correct, and with such a consciousness I entertain a confident hope that they will prove in a humble way instrumental towards breaking up the Anti-Opium confederacy, the objects of which are as undeserving of support as they have proved mischievous in their tendency.