In our issue of yesterday, we stated briefly the action, and the ground of action, of Virginia and the border States of the South in the late Charleston Convention. We stated that by remaining in the Convention they had secured two principles of the greatest importance to the South and to the Democratic party, and, by consequence, to the Union. The one of these was the adoption of a rule of nominations by which the strength of the whole South was to be so counted as that their dissent from any nomination would amount to a veto. This, it is obvious, will secure the nomination of a sound man, if the South can agree among themselves as to who is a sound man. The other principle gained was the recognition, by a distinct pledge, of those composing a majority of the Convention, that the Tennessee Resolution should be adopted. That resolution is as follows:

Resolved, That all citizens of the United States have an equal right to settle with their property in the Territories, and that under the decisions of the Supreme Court, which we recognize as an exposition of the Constitution, neither their rights of person or property can be destroyed or impaired by Congress.

This, which brings in the full force of the Dred Scott decision, repudiates Squatter Sovereignty and fixes the rights of the South on an impregnable basis. Those rights, thus secured by a rule which gives the South the control of the nomination, and an acknowledgment of a great principle, seem to us as containing all that it was necessary to demand of the North. For this reason we approve cordially of what Virginia did, and do not well see what else she could have done without error. We trust that on a calm review of the whole subject the seceding States will come to the same conclusion, and will unite with the Border States in Convention at Baltimore, and there secure for themselves, by action, the advantages that have been secured for them in principle.

We see that one of the papers representing the views of the seceders argues that if they return to the Convention at Baltimore, they will, in some, if not most, cases be met there by contested delegates from their States; and that as these will be Douglas Democrats, they will be admitted in such mode as to insult the retiring seceders. Now this result we do not anticipate. We are very sure it will not take place in Virginia; and we cannot imagine that if the delegations of other States have not been deemed to have forfeited the confidence of their constituents, that any attempt will be made to supersede them. But if it shall be, and shall prove successful, it will demonstrate that an opposition to the extreme Southern movement is to be made at home; which will be disastrous not only to the interests of the Democratic party, but to the slavery system of civilization. It must be admitted by the warmest advocates of Southern rights, that an explosion within our limits would rend us to atoms, whilst we may safely challenge outside pressure. In other words, we must be united to command respect to ourselves or safety to our society.

Suppose they shall not unite, but run an independent candidate as advised. With four candidates thus in the field, to wit: the Baltimore nominee, their candidate, the Whig or Opposition candidate, and the Chicago nominee, the election, of course, goes to Congress—the Whig will be dropped as lowest, and the seceding States must then elect between their own candidate, the Baltimore nominee and the Black Republican. In that event a Squatter Sovereignty man may, and most probably will, as the candidate of the Baltimore Convention, be submitted to their choice; and the question will be,—if their own man fails, as undoubtedly he will—whether these States will reject the Baltimore nominee, and thereby secure the election of the Chicago nominee: and so create the very state of things, on the happening of which they are pledged to disunion. It is just in that view of the future that we contemplate this crisis: how far the South will be held justified in the opinion of the world and in the sight of heaven for involving not the Union, but themselves, in a civil war upon the occurrence of an event which they could have prevented by the exercise of moderation, and by the use of means which are deemed abundantly sufficient by States at least as much interested as themselves in the institutions they seek to uphold. The action of the border States assures us that they think enough has been conceded to keep the Democratic party still united, and to give the South such a check upon it as to sustain their rights. These States now appeal to the seceders not to break up, and send new delegations, but they appeal to the seceding delegations themselves to come back and fight for their rights upon principles which must unite the South, because the border States are committed to it.

The invitation to fill vacancies cannot be construed into an invitation to appoint new delegations. It was issued for the sole purpose of securing complete delegations from each State in order that the South might have the benefit of her full strength. We have reason to know that it was worded expressly with the purpose of avoiding any opinion as to whether the voting of any delegation in whole or in part created vacancies.