Col. Seth J. Thomas was next called, and put, by the counsel for the defence, on his _voir dire_, as to any interest he might have in the penalties provided in the act. He answered that he was the counsel for Mr. De Bree, the owner of the alleged fugitive, and that he had received written instructions from his client in relation to the case of Shadrach; but he did not hold such a power of attorney as is contemplated in the fugitive act. His relations to the case were those of an attorney and counsellor of law, and as such he had advised with Mr. Caphart, the agent, who held such a power of attorney from Mr. De Bree as is intended in the act. Fees in no manner depended upon the result of the proceedings in the case. Mr. Dana inquired what was to be proved by this witness. _Mr. Lunt._ That the person under arrest was claimed as a fugitive. _Mr. Thomas._ Was here on Saturday last, saw a person called Shadrach, who was alleged to be a fugitive slave. This evidence was strongly objected to as hearsay, but held admissible by the Commissioner. _Cross examined._ My means of information is confined to others. Don't know that I ever saw the negro before. The Commissioner said that he had ruled that the Government were not obliged to show that Shadrach was a slave, and that no further evidence was necessary to show that he was arrested and escaped. _Mr. Davis._ The question now arises under the present warrant and complaint, which alleges not only that one Shadrach was a fugitive slave; but that the same Shadrach who was a slave to one De Bree, was rescued. The Commissioner has ruled that the Government are not obliged to prove that the man under arrest was a fugitive, or was a slave. Does the Commissioner also rule that the Government need not show that the man arrested was the man claimed, and that the man rescued was Shadrach? _The Commissioner._ The Government may prove by Col. Thomas that the man arrested was the man claimed. Here the question was discussed, whether the prosecution were bound to prove that the colored man arrested was the person intended in the warrant, and named Shadrach. The Commissioner again held that the returns on the warrant were _prima facie_ evidence that the man arrested was the said Shadrach. Mr. Dana thought Mr. Riley had destroyed the presumption arising from the return by having testified that he did not personally know whether the man was Shadrach or not; all he could say was that he knew he was the man he had arrested as Shadrach. Col. Thomas was allowed to testify, that the man arrested and brought into the court room was claimed by Caphart as Shadrach. When he came into the room Caphart said, "This is my boy." Col. Thomas produced a paper and testified to it as the power of attorney. Objected to on the ground that the signature was not proved. The Commissioner held that it was admissible as one of the papers before Mr. Curtis. _Simpson Clark_, recalled.