What does einen mean in English

Read the following excerpt from an official letter written during the nineteenth century. we find that your country is distant from us about sixty or seventy thousand miles, that your foreign ships come hither striving the one with the other for our trade, and for the simple reason of their strong desire to reap a profit…it follows, that the immense wealth which the said foreigners amass, ought properly speaking to be portion of our own native chinese people. by what principle of reason then, should these foreigners send in return a poisonous drug, which involves in destruction those very natives of china? which event in chinese history prompted these words?