DEAR MARIUS: It would astonish you to see how we are putting down Anti-Slavery 'agitation.' The great Dead-of-Disappointment blew his last breath away, in a vain endeavor to extinguish the flame of excitement which his own words and deeds had kindled on the subject of human slavery. Again and again, he commanded the agitation to cease. But it ceased not, though he did. He ceased and deceased; but the agitation swept on, with tornado power.

  Boston is still festooned with crepe and cambric all the way from Charles' River to the Heights of Dorchester, drooping in deep mourning over the loss of her favorite idol. The 'mottos' which appeal down so sadly to you in every conspicuous place, would make another 'Book of Lamentations.' Boston should be written Bochim, now—'the place of the weepers and mourners,' as in the days of the Hebrew Prophets.

  But the sincerity of the grief and mourning is pretty clearly seen. The Democrats were half consoled by the results of the presidential election. And now, a prominent and wealthy Boston whig, the proprietor of the most popular, and deservedly popular Theatre in the City, has just placed a dramatic representation of Uncle Tom's Cabin upon the stage, in a manner to bring the whole subject of slavery before the community as never before. I have long wished to behold such an achievement, as the surest prediction of the speedy overthrow of the slave system.

  And this is the way the admirers of Daniel Webster are heeding and consummating the last labors of his life, to save the Union, by silencing all Anti-Slavery agitation!

  And now, the Theatre is openly, where it has long been actually; before and better than the Church.

  Let the terrible fact be told in thunder round the world. In the Play, the slaveholder declares boldly, 'Slavery is of the Devil.' In most of the forty thousand ecclesiastical Theatres and Playhouses of our country, the ghostly performers solemnly say, it is of God. In the language of one large Presbytery, 'It is the Lord's doing, and marvellous in our eyes.'

  Now we have got the Theatre versus the Church, on the question of slavery. The Theatre says it is of the Devil. The Church claims that it is of God. Let us wait patiently for the verdict. The question is before a jury composed of the civilized world.

  Of the manner of the piece and of the performance, I need not now speak. It was Uncle Tom's Cabin, on the stage, and before one of the largest and best looking audiences I ever saw in any theatre. And five hundred people bought tickets in the forenoon for secured seats, at double price,—and excepting those seats, the house was almost literally crammed nearly an hour before the rising of the curtain. And the most radical sentiments, together with the shooting dead of the kidnappers in pursuit of 'George and Eliza,' were most loudly applauded:—and one thing more, the Play will, doubtless, from present appearances, be a fortune in the pocket of the proprietor of the museum. Vive la agitation!

Yours, as always, PARKER PILLSBURY.