FORT WARREN, Boston Harbor, November 30, 1861.

Honorable W. H. SEWARD, Secretary of State, Washington.

SIR: Mr. J. M. Mason wishes to send two bills of exchange on the Royal Bank, Liverpool, to England. One is for L1,600 and the other for L300, in all L1,900 sterling. I informed him I would retain his letter until I heard from you. The bills were given to the officer in charge of the prisoners' funds on Mr. Mason's arrival.

I am, sir, with the highest respect, your obedient servant,

J. DIMICK,

Colonel First Artillery, Commanding.

FOREIGN OFFICE, [London,] November 30, 1861.

Lord LYONS, K. C. B.,&c., Washington.

MY LORD: Intelligence of a very grave nature has reached Her Majesty's Government.

This intelligence was conveyed officially to the knowledge of the admiralty by Commander Williams, agent for mails on board the contract steamer Trent.

It appears from the letter of Commander Williams, dated "Royal Mail Contract Packet Trent, at sea, November 9," that the Trent left Havana on the 7th instant, with Her Majesty's mails for England, having on board numerous passengers. Commander Williams states that shortly after noon on the 8th a steamer having the appearance of a man-of-war but not showing colors was observed ahead. On nearing her at 1. 15 p. m. she fired a round shot from her pivot gun across the bows of the Trent and showed American colors. While the Trent was approaching her slowly the American vessel discharged a shell across the bows of the Trent exploding half a cable's length ahead of her. The Trent then stopped and an officer with a large armed guard of marines boarded her. The officer demanded a list of the passengers; and compliance with this demand being refused the officer said he had orders to arrest Messrs. Mason, Slidell, Macfarland and Eustis, and that he had sure information of their being passengers in the Trent. While some parley was going on upon this matter Mr. Slidell stepped forward and told the American officer that the four persons he had named were then standing before him. The commander of the Trent and Commander Williams prosted against the act of takingby force out of the Trent these four passengers then under the protection of the British flag. But the San Jacinto was at that time only 2oo yards from the Trent, her ship's company at quarters, her ports open and tompions out. Resistance was therefore out of the question and the four gentleman before named were forcibly taken out of the ship. A further demand was made that commander of the Trent should procedd on board the San Jacinto but he said he would not go unlesss forcibly compelled likewise and this demand was not insisted upon.

It thus appears that certain individuals have been forcibly taken from on board a British vessel, the ship of a neutral power, while such vessel was pursuing a lawful and innocent voyage-an act of violence which was an affront to the British flag and a violation of international law.

Her Majesty's Government bearing in mind the fiendly relations which have long subsisted between Great Britain and the United States are willing to believe that the U. S. naval officer who committed the aggression was not acting in comliance with any authorithy from his Government, or that if he conceived himself to be so authorized he