The Convention now in session at Wheeling, in which are represented about forty counties of Western Virginia, have, by a formal and unanimous vote, resolved to cut loose from the Old Dominion and form for themselves a new and independent State. What name they will give to their new Commonwealth is not yet discussed. It may be ALLEGHANY. But whatever the name, the fact will be the same. The great State of Virginia is to be dismembered by the voluntary act of over a half million of her late citizens; and a new State formed from the Western part of her territory will claim a place in the Union.

The action of the Convention will create surprise and some regret in the loyal States of the Union. Although the plan adopted was the first one proposed by Hon. JOHN S. CARLISLE, and urged at the former Convention at the same place, it was opposed by reasoning that then seemed to be conclusive; and the country remembers with satisfaction the patriotic promptness with which Mr. CARLISLE and his friends yielded to the decision against his policy. The better course for the loyal citizens of Western Virginia was judged to be, to claim still to be Virginia, and to treat Gov. LETCHER and the State authorities at Richmond as usurpers in renouncing the allegiance of Virginia to the Federal Government, and attempting to attach the State to a new and unknown Confederacy. The State Administration was to be considered in rebellion against the Constitution and laws, and to be superseded by a Provisional State Government, to be organized at Wheeling. The programme, it was supposed, would be carried out by the body now in session at Wheeling. But it has not been. It has been abandoned, and a complete separation from the old State of Virginia determined on.

The regret felt by a portion of the public at this action, arises from the fear that it may occasion embarrassment in failing to meet the approbation of Congress. If the Federal Government refuse to acknowledge the secession of a State, it cannot well recognize, in attempted secession, a cause for the dismemberment of a State by its loyal inhabitants, as a remedy for the evils with which they are threatened.

Then there are other questions touching the existence of Slavery in the new Commonwealth—for it would contain a considerable number of slaves—and the consequent increase of slave representation in the United States Senate would not fail to excite more or less jealousy in certain parts of the Union.

But these difficulties are rather technical than substantial. The division of a State and the creation of a new one out of a part of its territory is, under certain circumstances, feasible under the Federal Constitution. Virginia is a very large State, and very susceptible of division. It is not homogeneous in any respect. The Eastern part differs from the West in climate, soil and productions—in customs, political sentiments and institutions. The trade of the two divisions of the State falls into different channels and reaches the market by routes that require wholly different systems of internal improvements. And herein lies one cause for the deep feeling of alienation in Western Virginia from the Eastern portion of the State:—that the latter has, by an unfair basis of representation in the Legislature, founded on Slavery, controlled the internal improvement system of the State, and run up an enormous debt of near fifty millions of dollars which rests like an incubus on the people, for the advantage and development of the Eastern counties; while the West has received practically no share of the improvements they are taxed to pay for.

In the facts of their physical relation and political condition, there is abundant reason for Eastern and Western Virginia forming two separate and distinct Commonwealths; and apart from the connection of the present movement for dismemberment with secessionism, and the quasi acknowledgment of this modern political heresy that is supposed to be involved, the erection of a new State in Western Virginia might well be advocated as a wise and necessary measure.

It is to escape the crushing weight of a fifty million debt, incurred not by them, nor for their benefit, that the loyal citizens of Western Virginia feel compelled to cut loose from the Old Dominion and establish for themselves a new State. Let those who would condemn the action these loyal Virginians have taken, consider the alternative course. If a Provisional Government for Virginia had been formed by the forty counties, it would have been recognized by the Federal Government and by the world as the real State government. As such, it would have been held legally, as well as morally bound for every dollar of the enormous debt of the State of Virginia instead of its proper share only; and would have been compelled to commence a career of bankruptcy and repudiation just at a time when all its resources are needed to maintain existence against intestine foes.

The worst feature in the case would be that the debt is palpably unjust as regards the people, who would have to endure the weight of its burden, or the shame of its repudiation.

As for Slavery in the proposed new State, it will not be a deep-seated nor long-lived institution, and there would be no real reason to fear it.

We make these suggestions in justice to the loyal people of Western Virginia, and bespeak a candid consideration of their difficult position.