HEADQUARTERS DEPARTMENT OF VIRGINIA,
Fort Monroe, September 15, 1861.

Honorable SIMON CAMERON, Secretary of War.

SIR: I received yesterday from Major-General Dix a letter accompanying fifteen prisoners arrested in Baltimore of which the following is an extract:

The direction of the Secretary of War is to keep them in close custody, suffeirng no one to communicate with them, and convey them at once to Foretress Monroe there to remain in close custody until they shall be forwarded to their ultimate destination.

The prisoners Brown, May, Winans and others were landed at this post yesterday afternoon and have been placed in the casemates where they are strongly guarded. I have no other instructions or communications from the Government in regard to these prisoners than those contained in the above extract from a letter addressed to General Dix. Those instructions so far as the treatment of the prisoners while here is concerned may be susceptible of two constructions. Is it the intention of the Government that the prisoners shall neither receive nor send letter to their familier and friends of a purely domestic and private character to be ascertained by inspection?

The crowded state of this fortress which from the great number of stores and supplies within it has obliged me to place these prisoners in very close quarters where they cannot obtain even the necessary conveniences of health and must suffer seriously for the want of air and ventilation, and to detail a strong guard for their safe-keeping which with the reduced force now at my disposal has necessarily interfered with other important duties of the men.

I would suggest that this fortress from its position and the sympathies that surround it is neither so secure nor commodious a place for the safe-keeping of these prisoners as poins farther north. At the Rip Raps they could not be accommodated from great number of prisoners waiting there for conveyance to the Tortugas.

I would be pleased to receive as soon as possible from the Government instructions in regard to these prisoners.

I have the honor to be, very respectfully, your obedient servant,

JOHN E. WOOL,

Major-General.

[First indorsement.]

WAR DEPARTMENT, September 16, 1861.

Will the Secretary of State be good enough to read the within and inform me of his views?

SIMON CAMERON.

[Second indorsement.]

I advise that these prisoners be sent to Fort Lalayette or Fort Hamilton as General Scott may designate; that they be allowed to receive no visitors nor to communicate on any other than purely personal or domestic matters by letter to be inspected.

W. H. S[EWARD].

[Third indorsement.]

Will General Scott please designate the fort?

SIMON CAMERON,

Secretary of War.