Let the Douro pass on to our sons as our fathers left it to us." Now, when it is proposed to alter and confine the course of the Mississippi, we recall the arguments of the Iberian orators, and say to ourselves, if the member from St.Louis was as good an economist as those of Valencia, and the representatives from New Orleans as powerful logicians as those of Oporto, assuredly the Mississippi would be left "To sleep amid its forests dank and lone," for to improve the navigation of the Mississippi will favor the introduction of New Orleans products to the injury of St.Louis, and an inundation of the products of St.Louis to the detriment of New Orleans..