THE TWO-HORSE MISSION TO ST. DOMINGO.

The Tribune professes to have news of what the "Two-horse Mission," as it calls it, to St. Domingo, up to the 20th. It says that Mr. Cazneau has failed in his mission, and, it is understood, is to be withdrawn, because, upon examination, it has been found that the present Government of St. Domingo shall have the same political and physical relations to the United States that the rest of the world has, namely, foreign, in consideration of the Americans being mostly white, and most of the Dominicans being mostly black.

The Tribune's cause of this "step backward" is reported to be the fact that "the Dominicans are mostly of African descent. It seems that the Government was entirely satisfied with Mr. Cazneau's standard of a white man; but it now turns out that, to speak correct, the President has become cognizant of the color of the nation, only some months since, that there is not a single man connected with the Dominican Government, from the highest to the lowest, who, if brought into United States, would not, by the rule of the State Department, be entitled to a passport, and, strictly speaking, incapable of holding office in a foreign country. It seems our neighbors have got their eyes open, and our Administration is not yet prepared to recognize the nationality of Hayti or St. Domingo, or to exchange with them the international courtesies of independent nations. The Administration, they say, are—they have perceived, though too late for their credit, that they can have no dealings with the Dominicans as an independent nationality. Now, as the Administration have been pleased to avail themselves thus far of our advice in this business, they will pardon us for making one more suggestion. There is but one honest way of acquiring title to any real estate on the Bay of Samana, and that is by negotiations with the Emperor of Hayti, for he is the sovereign of the whole island—the Dominican Government being revolutionary and properly non-extant. The negotiations would be very simple, and the terms very favorable; for all that would be the first step to be taken would be to acknowledge the nationality of the empire—a position so compunctious about which so much pother was made, when it was proposed to acknowledge Hayti, or send a Consul or Commercial Agent. The Emperor of Hayti would, no doubt, gladly send Ministers, or Charges, or Consuls, to the United States, to set off against our Minister, President Pierce, or any of his Cabinet. He is too chivalrous to insist on any difference of color of his representatives here or elsewhere.

It will be a hard case, we own, for the United States for commercial advantages, if we could have no treaty of reciprocity or of alliance or commerce with the island, now some fifty years known as the Empire of Hayti. It makes it worth our while to cultivate friendly relations with them, and there is nothing in the way of it but the foolish fear of offending the Dominicans; which, it seems, is now pretty much over, the nation becoming daily more and more ashamed.

Though the Tribune does not give the source of its information about the results of the "two-horse mission" to St. Domingo, we presume it is derived from one of the span, as we learn that they have recently returned to the United States, and their dissatisfaction with the reception of their bargain is now naturally finding its way into the public journals. Is it possible that one of these gentlemen, to wake up his resolution about the acknowledgment of the nationality of St. Domingo, which he offered, it is promised to wake it up the next day, and yet it has already slept nine months—an ominous number. Surely it is time something came of it.