MR. McDUFFIE IN RICHMOND.—The speech of this gentleman from the general account, (we did not hear it or wish to hear it) on Tuesday night, was the most ultra in doctrine and in spirit, and the most directly levelled at the root of the existing institutions of this country, of any ever made within its wide limits. It was not less false in doctrine, than bitter in personal bearing, exasperated in temper and feeling. treasonable in meaning and intention, and impotent in style and execution. He fell, all say, far below expectation—raving where he should have enlightened, denouncing where he was most bound to praise, singulating where it was most imperative on him to be candid, and throughout, disclosing to the sagacious auditor, purposes and designs which he would not and durst not avow. Affecting to be a friend of the Union, he argued against its value and utility, and attempted to prove its injustice and oppression. Assuming to wish the continuance of the Union, he tried to show that none but Slaves would desire its continuance for a moment. Talking of fraternity and brotherly love, he exhibited a state of feeling more hostile to our brethren of the North, than England ever had for France, or the Mussulman for the Christian. Descanting upon Free Trade, political economy, and kindred subjects, he broached the wildest theories which were surely ever addressed to cultivated reason! For example, he said that the South paid everything, and that the North did not work at all! The people of the North, he said, did nothing but travel and divert themselves, the South furnishing [under the Tariff,] the expense and paying for the fiddler! He represented the South [Cotton] as laboring for the North almost exclusively, while the North, and especially the Ladies, were travelling to and fro, hither and thither, in such crowds. that He, Mr. McDuffie. could with difficulty obtain a seat in a Rail Road Car! "In short, the idea he presented was, that he and his Cotton growers, who have negro girls to fan the gnats off them, were Hard at work all the time, especially when the Cotton was growing, while Brother Jonathan north of the Potomac, was living upon their labor, and fiddling, frolicking and junketing! A more extraordinary set of opinions we do not believe ever entered the head of a sane man—if sane he can be called who has studied Cotton and Cotton Bale Theories until he has become as mad as Don Quixotte was rendered by the romance of Amadis de Gaul, and Don Cirongillo of Thrace! Mr. McDuffie has made no impression here. except that his once fine powers have sunk under physical disease, except that his heart in spite of his professions is at utter enmity with the union of these States. and if he could be would dissolve it now, not in anticipation of the evil to come, but in respect to that which, as he pretends, already exists and weighs down the vital energies of the Southern States! That such a man should hold such an opinion is a metaphysical phenomenon which we shall not attempt to explain if he really does hold it. But we confess it is still more extraordinary that such a man should profess to hold an opinion which he does not entertain—for we subscribe fully to the high claims of Gen. McDuffie to unsullied honor. We are disposed to solve the "riddle" by the conjecture that Mr. McDuffie is Calhoun and Cotton mad in the monomania sense, and that he has been rendered so by the intense desire of all of his School to make Mr. Calhoun President: or, if he could not rule in Rome, that he should in Praneste; for the school at large think generally with another who has been sung of, that it is "better to rule in Hell, than serve in Heaven."—Richmond Whig.