One who is personally unknown to you, and to whose Character you are probably equally a stranger, considers it both a Right, and a Duty to communicate to you, as chief Magistrate of the United States, a circumstance from which it seems presumable that the honor, the dignity, and integrity of the national character have been committed by persons holding honorable Commissions under the Authority of the United States.

I dined yesterday at the house of a respectable Gentleman of this town in company with Mr. John Fenton Mercer, a native of this place, and a midshipman belonging to the United States’ Ship Baltimore commanded by Capt. William Cowper, who has lately returned to the United States in a prize taken and sent in, (as I understand) by the Enterprise Capt. Shaw. The Conversation among other subjects turn’d upon the mode of life he had been lately engaged in, when he related the following extraordinary Facts.

That the French Brigantine Esperance, an unarmed Merchant vessel, was some months past taken by the Baltimore, and afterwards sent into Virginia and condemned in the Admiralty Court at Williamsburg. That previous to sending a prize Master on board the Brigantine, a boat was sent on board with a parcel of Muskets and Cutlasses, to be put on board the prize, and then, Mr. John McFarlane, Master’s–Mate on board the Baltimore was sent on board the Brigantine to take charge of her as prize master, and the Arms were sent back on board the Baltimore. That this was done, that Mr. McFarlane and those who went on board with him might be able to swear that they found Arms on board the Brigantine when they first went on board. Thus he has since seen Mr. McFarlane, who congratulated him on the success of the expedient to obtain the Condemnation of the prize, as she would not have been condemned if he had not positively sworne, that he found Arms on board the Briganatine, when he went on board to take charge of her.

Mr. Mercer said, that he has reason to believe that this was by no means the only Instance of such a practice; that it was generally done where there could be a doubt whether the prize was armed or not; and that he has reason to believe that the same thing is generally practiced in the American Navy to evade the Act of Congress Which does not subject unarmed vessels to Capture and Condemnation. He spoke respectfully of Capt. Cowper and Mr. McFarlane, and seemed willing to excuse both, upon the ground that the thing was generally done in the navy, from the motives abovementioned.

Prompted by the consideration that facts of this nature are not more easy in the Commission, than difficult in the Detection, I have resolved to give you that Information, which probably Accident only could ever render obtainable.

I am unacquainted with Mr. Mercer; his family is very respectable; his Education I hear has been liberal; the Station he holds in the American navy entitles his declarations to respect; and the manner in which they were made left no room for doubt in the breast of any person present that they were well founded. He added, that if called upon he was ready to depose to the Truth of them.

Should you deem it necessary to make any inquiries respecting the writer of this Letter, the Secretary of State, or the Attorney General will be able to satisfy them.

I am / With due Consideration & respect, / Sir, / Your obedt. Servn.