Ex-Judge ROOSEVELT, United States District Attorney, said—During this short interval I should remark, in addition to what has been said by Mr. Hunt, that upon looking over this case, although I took no part in it in open court, that the prosecution came to the conclusion that this testimony was entirely unnecessary, though relevant; and the only reason why any delay should have been asked, and the only reason why any delay should have been granted, was to follow out the usage founded on good sense and on humanity—that usage which has been regarded, not by strict law, but by a species of courtesy, that the government, being the stronger party, should not, at the outset, take sides, as it were, but develop the entire case, whether they lay before the court items which may be deemed by them not to be very important, because it might so happen to the mind of the court and the minds of the jurors, that those items, which we might deem not important, should seem to be very necessary to make out the case. I did not consider the testimony of Captain Nickerson in any other light than in completing the history of the case. On the other side, they had a right to object to the introduction of what Captain Nickerson had sworn to before the commissioner, and it was perfectly proper they should do so, unless the evidence was introduced in the regular way. On our part we have endeavored to do our full duty to the court, to the prisoner, and to the public. We have tried to give every element, every item of evidence in the case that had the slightest bearing upon it; and I would now say, to avoid any misapprehension, that it does not arise from any idea of the weakness of the case by any means; but it is to fill out, if possible, the usage of the courts in criminal cases. But we are unable to procure this witness; he probably is on the ocean now, for he sailed from Philadelphia for Boston last week, and is now at sea. If, however, he should arrive in the course of the day, it will be for the court to say whether it will take his testimony or not, and for the prisoner’s counsel as to whether they will object to it or not. The COURT.—It appears to me that this is a proper view of the case taken by the United States Attorney. It is the duty of the government, especially in a case of high crime—such a case as the prisoner is charged with—to lay before the court and jury all the evidence they have in their power, or that they are cognizant of, which has any connection with or bearing on the case; and, as the court intimated yesterday, whatever may be its opinions in relation to the necessity of the evidence, such as Captain Nickerson’s might be, it would be very improper for the court to intimate it at this stage of the trial.