Then came an argument on the constitutional question, and then the reasons for the exercise of the power as a general policy.  The first point was that it would prevent further inequality of representation, such as existed under the Constitution in the old States, but which could not be increased without danger.  The next argument went straight to the merits of the question, as involved in slavery as a system.  After pointing out the value of the ordinance of 1787 to the Northwest, the memorial continued:—­

“We appeal to the justice and the wisdom of the national councils to prevent the further progress of a great and serious evil.  We appeal to those who look forward to the remote consequences of their measures, and who cannot balance a temporary or trifling convenience, if there were such, against a permanent growing and desolating evil.

“...  The Missouri territory is a new country.  If its extensive and fertile fields shall be opened as a market for slaves, the government will seem to become a party to a traffic, which in so many acts, through so many years, it has denounced as impolitic, unchristian, and inhuman....  The laws of the United States have denounced heavy penalties against the traffic in slaves, because such traffic is deemed unjust and inhuman.  We appeal to the spirit of these laws; we appeal to this justice and humanity; we ask whether they ought not to operate, on the present occasion, with all their force?  We have a strong feeling of the injustice of any toleration of slavery.  Circumstances have entailed it on a portion of our community, which cannot be immediately relieved from it without consequences more injurious than the suffering of the evil.  But to permit it in a new country, where yet no habits are formed which render it indispensable, what is it but to encourage that rapacity and fraud and violence against which we have so long pointed the denunciation of our penal code?  What is it but to tarnish the proud fame of the country?  What is it but to render questionable all its professions of regard for the rights of humanity and the liberties of mankind.”

A year later Mr. Webster again spoke on one portion of this subject, and in the same tone of deep hostility and reproach.  This second instance was that famous and much quoted passage of his Plymouth oration in which he denounced the African slave-trade.  Every one remembers the ringing words:—­

“I hear the sound of the hammer, I see the smoke of the furnaces where manacles and fetters are still forged for human limbs.  I see the visages of those who, by stealth and at midnight, labor in this work of hell,—­foul and dark as may become the artificers of such instruments of misery and torture.  Let that spot be purified, or let it cease to be of New England.  Let it be purified, or let it be set aside from the Christian world; let it be put out of the circle of human sympathies and human regards, and let civilized