The only manner in which the right of secession could exist in one of the American States, would be by an express reservation to that effect, in the Constitution. There is no such clause; did it exist it would change the whole character of the Government, rendering it a mere alliance, instead of being that which it now is--a lasting Union. But, whatever may be the legal principles connected with this serious subject, there always exists, in large bodies of men, a power to change their institutions by means of the strong hand. This is termed the right of revolution, and it has often been appealed to to redress grievances that could be removed by no other agency. It is undeniable that the institution of domestic slavery as it now exists in what are termed the Southern and South-Western States of this country, creates an interest of the most delicate and sensitive character. Nearly one half of the entire property of the slave-holding States consists in this right to the services of human beings of a race so different from our own as to render any amalgamation to the last degree improbable, if not impossible. Any one may easily estimate the deep interest that the masters feel in the preservation of their property. The spirit of the age is decidedly against them, and of this they must be sensible; it doubly augments their anxiety for the future. The natural increase, moreover, of these human chattels renders an outlet indispensable, or they will soon cease to be profitable by the excess of their numbers. To these facts we owe the figments which have rendered the Southern school of logicians a little presuming, perhaps, and certainly very sophistical. Among other theories we find the bold one, that the Territories of the United States are the property, not of the several States, but of their individual people; in other words, that the native of New York or Rhode Island, regardless of the laws of the country, has a right to remove to any one of these Territories, carry with him just such property as he may see fit, and make such use of it as he may find convenient. This is a novel co-partnership in jurisdiction, to say the least, and really does not seem worthy of a serious reply.