It appeared from the testimony on the part of the prosecution, unmistakably, that, during the fall of 1864 and the winter of 1864-5, Booth was brooding over a wild plot for the capture of the President (either on one of his drives, or in the theatre, where the lights were to be turned off), then hurrying off the captive to lower Maryland, thence across the Potomac, and thence to Richmond; thereby to force an exchange of prisoners, if not, possibly, a cessation of the war. It was a plot of the kind to emanate from the disordered brain of a young, spoiled, dissipated and disappointed actor. During this period, Booth made some trifling and miserably inadequate preparations, and endeavored to enlist some of his associates in its execution; and, by his personal ascendency over them, he did in fact entangle, in a more or less vague adhesion to the plot, Arnold, O'Laughlin, Atzerodt, Payne, Herold, John H. Surratt, Lloyd, and, possibly, Dr. Mudd and Weichman. On the fall of Richmond, and the surrender of Lee, this any-how impracticable scheme was necessarily abandoned. Indeed, the proof showed that Arnold and O'Laughlin had deserted their leader some time before. It further appeared in the testimony that it was not until after the forced abandonment of this plot and the desertion of most of his adherents, that Booth, plunged as he was into the depths of chagrin and despair because of the collapse of the rebellion, suddenly, as a mere after-thought, the offspring of a spirit of impotent revenge, seized upon the idea of murder, which was not in fact brought to the birth until the afternoon of the fourteenth, when he was first informed of the promised attendance of President Lincoln and General Grant at the theatre. Now, the existence of the plot to capture, although it looked forth from the evidence steadily into their faces, the Judge-Advocates bound themselves not to recognize. In the first place, such a concession would forever demolish the preconceived theory of the Secretary of War, Colonel Baker and the Bureau of Military Justice, that the conspiracy to murder emanated from the Confederate Government through its Canadian agents, by pointing directly to another plot than the one to kill as that in which these agents had been interested. The horrid monster of a widespread, treasonable conspiracy to overthrow the government, which had been conjured up in the imagination of the Secretary of War and then cherished in the secret recesses of the Bureau of Military Justice, would have immediately shrunk into the comparatively simple case of an assassination of the President and an attempted assassination of the Secretary of State, by two worthless villains suddenly seizing opportunity by the forelock to accomplish their murderous purpose. And, in the next place, the concession of such a plot as a fact would go far to establish the innocence of Mrs. Surratt, Arnold, O'Laughlin and Mudd, as well as that of John H. Surratt,