And an attack upon the slave _traffic_ alone will never prove adequate. The history of our country's dealing with negro slavery is instructive on this point. There were laws in abundance for the suppression of the _traffic_ between Africa and America; it was forbidden to bring slaves into the country, and devices were invented looking to an eventual liberation of all the slaves in certain regions; but what did all these amount to, so long as slavery could exist? There had to be one sweeping, general emancipation of slaves wherever they were found, under whatever circumstances, and when the state of slavery was abolished, the trade in slaves died a natural death. The words of Mr. Francis concerning conditions at Hong Kong bear directly on this point: "Until the system of prostitution which prevails in this Colony ... is declared to be _slavery_, and treated and punished as such in Hong Kong, no stop will ever be put to the kidnaping of women and the buying and selling of female children in Hong Kong. This buying and selling and kidnaping is only an effect, of which the existing system of Chinese prostitution is the cause." In 1880, Mr. Berry, a member of the House of Representatives from California, made use, in a debate in the House, of the argument that "if the British authorities had not been able to prevent slavery from being practiced in Hong Kong, there would be great danger that, if an unlimited immigration of Chinese were allowed, it would be followed by the prevalence of slavery in this country."