The last man, who sits on the extreme right of the prisoners, is Mr. Sam. Arnold. He is, perhaps, the best looking of the prisoners, and the least implicated. He has a solid, pleasant face; has been a rebel soldier, foolishly committed himself to Booth, with perhaps no intention to do a crime, recanted in pen and ink, and was made a national character. Had he recanted by word of mouth he might have saved himself unpleasant dreams. This shows everybody the absurdity of writing what they can so easily say. The best thing Arnold ever wrote was his letter to Booth refusing to engage in murder. Yet this recantation is more in evidence against than then his original purpose. Arnold looks out of the window, and feels easy. The reporters who are present are generally young fellows, practical and ardent, like Woods, of Boston; Colburn, of THE WORLD; and Major Poore, who has been the chronicler of such scenes for twenty years. Ber. Pitman, one of the authors of phonetic writing, is among the official reporters, and the Murphies, who could report the lightning, if it could talk, are slashing down history as it passes in at their ears and runs out at their fingers' ends. The counsel for the accused strike me as being commonplace lawyers. They either have no chance or no pluck to assert the dignity of their profession. Reverdy Johnson is not here. The first day disgusted him, as he is a practitioner of _law_. Yet the best word of the trial has been his: "I, gentlemen, am a member of that body of legislators which creates courts-martial and major-generals!" The commission has collectively an imposing appearance: the face of Judge Holt is swarthy; he questions with slow utterance, holding the witness in his cold, measuring eye. Hunter, who sits at the opposite end of the table, shuts his eyes now and then, either to sleep or think, or both, and the other generals take a note or two, and watch for occasions to distinguish themselves. Excepting Judge Holt, the court has shown as little ability as could be expected from soldiers, placed in unenviable publicity, and upon a duty for which they are disqualified, both by education and acumen. Witness the lack of dignity in Hunter, who opened the court by a coarse allusion to "humbug chivalry;" of Lew. Wallace, whose heat and intolerance were appropriately urged in the most exceptional English; of Howe, whose tirade against the rebel General Johnson was feeble as it was ungenerous! This court was needed to show us at least the petty tyranny of martial law and the pettiness of martial jurists. The counsel for the defence have just enough show to make the unfairness of the trial partake of hypocrisy, and the wideness of the subjects discussed makes one imagine that the object of the commission is to write a cyclopedia, and not to hang or acquit six or eight miserable wretches. LETTER IX. THE EXECUTIONS. Washington, Friday, July 7th.