The St. Louis Republican says that those who heard or have read the speech of Hon. JOHN J. CRITTENDEN, delivered in that city on Monday evening last, will not have failed to observe the apprehensions expressed by that venerable statesman as to the effect upon the Union of the election of ABRAHAM LINCOLN to the Presidency. It were well—infinitely well for the country if it could be safely assumed that those apprehensions are groundless. But, as we have before declared, there is, unhappily, too much reason to fear imminent danger from the fiendish designs and efforts of the enemies of the Union. We have endeavored faithfully to do our duty in exposing those designs and efforts ever since they manifested themselves in the disruption of the Charleston Convention. We have shown, again and again, that the influences which produced that disruption, proceeded from those who were intent on destroying the Union, and that their machinations were deliberately directed to the one great object of effecting the election of LINCOLN, in order that they might avail themselves of that result as a ground for “PRECIPITATING THE COTTON STATES INTO A REVOLUTION.” As we near the period when those machinations appear to be reaching their culmination, let us calmly inquire what is to be the end of all this? Never was a more momentous inquiry presented to any people. He who turns away from it, or treats it lightly, may very soon find that he has committed an error for which there may be no possible remedy.

In the first place, in the language of Mr. CRITTENDEN—”THERE NEVER WAS SUCH A FINANCIAL AND PECUNIARY CRISIS IN THIS COUNTRY AS THAT WOULD BRING.” No powers of description can give any adequate impression of the disastrous effects upon all our material interests, if the country should once become involved in the throes of attempted disunion. We have no disposition to become alarmists unnecessarily, but we can perceive no hope for the agricultural, manufacturing and commercial interests of the nation, if that awful extremity should be reached. There are those who would disregard the prophetic warning; but if the country should be precipitated into disunion, night does not follow day with more inevitable succession, than will universal bankruptcy soon overwhelm the entire nation. Men who now are counted affluent will see their wealth drop from their grasp, and themselves and their families reduced to want. Every branch of industry will be struck with an instantaneous and deadly paralysis. The artisan and laborer will be without employment, because capital will have vanished; and soon the cry of the strong man for bread will be heard in accents of woe and dread, in every part of the land. A people who have never heard that cry, have but a poor conception of the gloom and terror it will carry to every heart. And what shall follow it? Can we hope that such a day of tribulation would pass, without bringing with it fire and blood—the torch of the incendiary, the blow of the assassin, the war of the poor for food, the struggle of men for life? But we will not follow the gloomy train of thought which this view of the impending danger begets.

But if we turn from it, shall we find any more cheering prospects in other directions? Can secession be attempted by any State without inevitable bloodshed? And if the blood of American citizens be shed by American citizens in such a struggle, when will it cease to flow? Ay, when will it cease? He who can answer that question with certainty, can tell when the bad passions of man will cease to hurry them into crime, when peace shall be universal, when strife shall cease on earth, and love shall encircle the world with the gentle bonds of universal brotherhood. And when the fatal blow shall be struck, what will be the effect upon those noble institutions which our fathers bequeathed us, and which we have been accustomed to regard as resting upon impregnable foundations, because those foundations were cemented with their blood? Can they stand? Is it possible for them to endure such a shock? We are constrained to declare that we do not see how they can bear up against it. They were made for a people linked together as brothers, not for a divided nation whose several parts are at war with each other. The simple, undisguised, and terrible truth is that if once the fires of civil war be kindled they will burn until all is consumed that can be, and the land shall become a waste, over which shall brood the silence of an utter and hopeless desolation.

If this is to be the end of this people and their Government, at whose door lays the mighty wrong? Can there be any doubt on this point? Can not every man in the Nation see that the fomenters of sectional discord are the authors of it? Under no conceivable circumstance would a struggle between any two National parties have produced the dangers of the present hour. The Northern Sectionalists, in their insane warfare against an institution which enters into all the interests and all the relations of the South, have been met by the Disunionists with an equally insane demand for the exercise of the power of the Federal Government to protect that institution in a region and under circumstances requiring no such protection. The latter have seized the occasion to exact what they know can not possibly be granted, and to base upon the failure to grant it, the deadly resort to revolution. There was no evil threatened, for which the Constitution and the laws do not afford a peaceful, complete and permanent remedy; but it was no part of the traitorous designs of Southern revolutionists to appeal to the means of Constitutional redress. For years they waited for an opportunity to bring their treasonable purposes into action, and they found or made it in the contest of the present year. They met a willing ally in the present occupant of the Presidential chair; and under the united impulse of hostility to the Union and hatred toward STEPHEN A. DOUGLAS, the traitorous movement was begun, which now threatens to destroy the country.

With renewed energy we invoke every man in the country to bear witness that upon the originators and supporters of the plot which presented JOHN C. BRECKINRIDGE as a candidate before the people, rests the terrible responsibility of the perils which now environ us. But for them the Democratic party would have been united over the whole country, and would have defeated LINCOLN, and overthrown his party with an irretrievable defeat. But for the divisions they produced in that party, the great Union loving element which now ranges itself under the lead of BELL and EVERETT, would have sided and acted with the Democracy in the North and the South, and fanaticism and treason in all their forms would have been at once and finally, repulsed. Upon them must forever rest the deathless odium of the overthrow of our institutions, if they fall. Let them, if they can, meet the dire retribution which, sooner or later, must visit those who precipitate the ruin of the noblest fabric of freedom that men have ever reared or looked upon.