Louisiana is about to secede from the Union on paper. The Ordinance of Secession will probably be reported to, and adopted by, the Convention to-day. The fact about the State of Louisiana is, it contains the mouth of the Mississippi river. There is a tradition that the mouth of the river is essential to the commerce of the Mississippi Valley. Among the things that have come down to us from a former generation is this tradition. Forty years ago the mouth of the river was all important to the people of the country watered by it. There was no other way of reaching European or other foreign markets, or even our own Atlantic ports. But we have changed all this, and have heretofore neglected to make a memorandum of the fact. An immense majority of the people of the Northwest doubtless believe that the loss of the command of the mouth of the Mississippi would be a tremendous misfortune. We undertake to maintain that practically the people of Ohio, Kentucky, Indiana, Elinois, and all the rest of the great Northern Mississippi Valley States, are more interested in the management of the four great Railroads to the seaboard, and of the Erie Canal, than they are in any possible proceeding at the mouth of the Mississippi. The blockade which we endured a few years ago, from the action of the pea-nut rioters of Erie, in tearing up the Lake Shore Railroad, subjected us to greater inconvenience and loss, than we would have to endure if the Mississippi were blockaded by pirates on the water or the land.

The proportion of the products of the Northern States of the Mississippi Valley that are exported by way of New Orleans, is not more than one tenth of the aggregate. Our flour and pork and other articles of foreign exportation, go East rather than South, finding their way into our Atlantic ports, and wherever there is a market, by way of the lakes, the Erie Canal, and the four magnificent railroads, two of which conquer, while two evade the mountains, altogether making New York, Philadelphia and Baltimore, our neighboring cities, while New Orleans is remote. Therefore the mouth of the Mississippi is not the orifice, through which Western commerce breathes and has its being. New Orleans is simply the agent of the Mississippi Valley trade. We would not disparage her. She is a splendid city. But, if there is any one thing, in which she is more interested than in any other, it is the freedom of the majestic river, to which she conforms her crescent of wharves. It might not require Mr. GURLEY’s military arm to hasten her conversion into an al[l]igator hole, if the despotism of her political fanatics should stop the trade of the North to and through her. Stop the mouth of the Mississippi and New Orleans perishes, but Cincinnati would flourish as usual. Already it is demonstrated that the currents of commerce do not necessarily run with those of the rivers that are its channels. King Cotton is in rebellion, and all appliances of King Caucus are inadequate to quell him. But never did King Cotton make so profound an obeisance to the Queen City of the West, as now. He turns out to be simply a subordinate to the majestic laws of Commerce. The steamers laden with cotton are turning their bows up the river, seeking a secure market for His Royal Highness, the Southern Staple, which we were told would be withheld that our ruin might secure humiliation, and instruct us in loyalty to the royal product of Southern soil and its lordly cultivators. We all learn that if cotton is one of the necessaries of life, bread and meat are not less so; and the cotton money comes to Cincinnati every day, to buy food for the hands on the Southern plantations. Our steamboats go down the river loaded with the property of our Southern customers—pork, flour, whisky—paid for in hard cash by Southern men. Who shall build batteries to sink them? Will Southerners send their bread and meat to the bottom of the river? Will they molest the boats on their up trips with the products of Southern soil that we require? The truth is, we may not reasonably apprehend that the commerce of the Mississippi Valley will be long or seriously interrupted or embarrassed by any difficulty arising from the Secession movement. The Seceders will but strangulate themselves if they meddle with the mouth of the river; and any restrictive policy they may attempt, will pass away before the irresistible operation of the commercial forces set in motion by the productive industry of the Northern and Southern States—the interchange of the products of the respective sections, being a necessity as far beyond the control of the madmen or fools who would restrain it, as the tides or the trade-winds.