His next communication was from Montreal under date of 8th of December, 1865, of which the following is a copy:

MONTREAL, December 8, 1865.

Brigadier-General HOLT, Judge-Advocate-General:

DEAR SIR: I have found Carter at last. My search for him in Toronto revealed the fact that he had changed his abode to Montreal. I doubted the propriety of my coming here, but knowing the importance of securing the party I determined to take the risk. I found Carter yesterday, made his acquaintance, &c., but only two hours ago did I disclose to him my mission and propose that he should accompany me to Washington, &c. He consents, and assures me that he knows of a score who will testify, if requested, to facts more important than any he can speak of. He agrees entirely with McGill except thta he can go a little further. I think I can promise more than Carter; I shall see. The rebs know of my presence here. I am informed that I will be arrested again. "To be forewarned is to be forearmed," and I can reckon myself safe. I shall leave, if permitted, thsi evening for Toronto again, where Carter assures me there are a dozen who will become witnesses in the matter in question. I called on Mr. Perkins, an eminent lawyer, some months ago counsel for Honorable Joshua Giddings, consul-general here, in a prosecution against him, and have been fortified by a knowledge of my rights under the laws of the Province, and on the strength thereof think I may consider myself safe.

Respectfully, your obedient servant,

S. CONOVER.

Afterward Conover telegraphed me from Montreal as follows:

MONTREAL, December 13, 1865.

Brigadier-General HOLT, Judge-Advocate-General:

Have just returned from Quebec. Have three very important witnesses. Require more funds; send $100 by express in care of D. T. Irish. Shall return the moment I hear from you. Expect another witness here. Answer this dispatch care of Mr. Irish.

S. C.

On the 20th of December he wrote me at length from Montreal, professing to give much in detail the very important testimony he had discovered, the character of the inquiries which had led to its discovery, together with the names of the witnesses. This letter, which he stated he would send by the witness Carter, came to me through the mail, accompanied by a note from Carter dated New York, December 27, 1865, of which note and letter the following are copies:

NEW YORK, December 27, 1865.

SIR: I send you from here a letter given me for you by Mr. Conover. I expected to stop in this place only one day, but I want to see Mr. McGill before coming to Washington, and he is in Providence and will not get back till Saturday, and I will wait for him and come on next Tuesday. It may be necessary for you to have Mr. Conover's letter before I come, so I will send it to you by mail.

Yours, respectfully,

WM. H. CARTER.

MONTREAL, December 20, 1865.

DEAR SIR: Agreeably to my promise in my note of yesterday morning I proceed to report more at length my proceedings under mylate missions. Other business prevented my writing last evening, and I shall not leave here for Toronto until this evening. You will receive this letter at the hands of Carter, whom I deem it advisable to forward from here at once, as he is anxious before making a deposition to see McGill and "compare notes," as he expresses it, in order that there may be no unnecessary discrepancy in their testimony. His statement does not differ in the least, if my memory serves me well, from McGill's deposition, except that he recollects one very important fact and occurrence which McGill must have forgotten or inadvertently omitted to disclose. Carter, who is quite intelligent, is confident that he can refresh the memory of his friend and make him recollect all that he does himself, and I think it very important that he should do so. The next witness I have in hand is named Mott. Like McGill and Carter he was seduced into hostility to the United States by extravagant promises by Clay and other prominent rebels. I cannot undertake to give you more than a brief synopsis of his statement. He knew Clay quite well; was several times present at his room when the subject of raids on the frontier was discussed, and had one private interview with Clay on the subject. This interview was just after the Saint Albans raid, and Clay, among other