Last winter a bill for the capture of fugitive slaves was introduced into the Senate of the United States of America; the Senator who so ably represented the opinions and wishes of the controlling men of this city, proposed to support that bill, "with all its provisions to the fullest extent;" that bill, with various alterations, some for the better, others for the worse, has become a law--it received the vote of the Representative from Boston, who was not sent there, I hope, for the purpose of voting for it. That statute allows the slaveholder, or his agent, to come here, and by summary process seize a fugitive slave, and, without the formality of a trial by jury, to carry him back to eternal bondage. The statute makes it the official business of certain magistrates to aid in enslaving a man; it empowers them to call out force enough to overcome any resistance which may be offered, to summon the bystanders to aid in that work. It provides a punishment for any one who shall aid and abet, directly or indirectly, and harbor or conceal the man who is seeking to maintain his natural and unalienable right to life, liberty, and the pursuit of happiness. He may be fined a thousand dollars, imprisoned six months, and be liable to a civil action for a thousand dollars more! This statute is not to be laid to the charge of the slaveholders of the South alone; its most effective supporters are northern men; Boston is more to be blamed for it than Charleston or Savannah, for nearly a thousand persons of this city and neighborhood, most of them men of influence through money if by no other means, addressed a letter of thanks to the distinguished man who had volunteered to support that infamous bill, telling him that he had "convinced the understanding and touched the conscience of the nation." A man falls low when he consents to be a slave, and is spurned for his lack of manhood; to consent to be a catcher of fugitive slaves is to fall lower yet; but to consent to be the defender of a slave-catcher--it is seldom that human nature is base enough for that. But such examples are found in this city! This is now the law of the land. It is the official business of judges, commissioners and marshals, as magistrates, to execute the statute and deliver a fugitive up to slavery; it is your official business and mine, as citizens, when legally summoned, to aid in capturing the man. Does the command make it any man's duty? The natural duty to keep the law of God overrides the obligation to observe any human statute, and continually commands us to love a man and not hate him, to do him justice, and not injustice, to allow him his natural rights not alienated by himself; yes, to defend him in them, not only by all means legal, but by all means moral.