Fokeion Office, ) Nov. 30, 1861. My Lord - Intelligence of a very grave nature bas reached her Majosty'a govornmeut. This ntelligence was convoycd ofTtcinlly to the koowledce of the Admiralty by Gommaoder Williams, agent for mails on board the contract steamer Trent. It appears frora the letter of Commander Williams, dated lloyal Mail Contract Packet ïreut, at sea, November 9th, that the Trcnt left Havana on tho 7th iustant with her Majcsty's mails for Eugland, haring on board numerous passengers. Commander Williams states hat ghortly after noon ou the 8th a teamer having the appearanoö of a manof war, but not showing colora, was oborved ahead. On nearing her, at a quarter past one P, M , she íired a round hot from her pivot gun across the Trent, and showed American colora. While lic Trent was approaching her slowly, he American vessel diícharged a shell acros the bows of the Trent, exploding lalf a cablu's length ahead of lier. The L'reut then stopped, and au offieer with a argc armed guard of marines boarded ïcr. The officer dcmandud n list of the passenger, and, compliance with this demand being refused, the offieer said he had orders to arrest Messrs. Mason, Slidell, MoFarland aid Eustis, and that he had sure information of tlicir being passengers in the Trent. While nonio parley was goiiig on upon this matter, .Mr. Slidell steppcd forward and told the American ulïicor that the four persons he liad named were then standing beforo him. The commander of the Trent and commander Williams protestcd against the act of taking by force, out of tho Trent, these four passenge, then under the protection ef the British (lag. ]5ut the San Jacinto was ;it that timo only two hundred yards i'rom tho Trent, her ship's eompauy at omifteY, hor ports open and tompions ouc. Kesistance waa thurefore out of tho questiou, and the four gentlemen bofore named werc forcibly taken out of the ship. A further demand was made ihat the coiumander of tho Ireut sbould prócéed on board the San Jaointo out ke suid ho would not go unless forciLily eotnpelled likewiso, and tbis demand was not iusisted upon. It tlius appears that ccrtain individuals hava been forcibly taken from on board a Britiah vessel, the ship of a neutral power, wbjle Bch vessel was pursuing :i lawt'ul and inuooont voyage, an act. of yiolenoe wbioh was an aü'rout to the liritish Üag and a violation of international Iaw. Hor Majesty's government, having in mind the triendly relations whioh have long Bubsisted betweuu Great liritain and the United States, are williug to believo that the Uuited States naval officer who oommitted this aggression was not acting in compliauce with any authority from liis government, or that, if lie conceivo 1 himself to be so autliorized, ho greatly misui'.derstood tbc instructions whieh bo had reccived. For tlie government of lbo United States must be fully aware that the Britisli government could not allow such an affront te tho nationul honor to paes without full reparation, aod her Majesty's government aro unwilling to belicve that it could be thc delibérate intention of tho goveriitiii":! of Mie Tií(.'l States unnec'ss.nlv tu forco hito d:?ousio:) hatwoun tlio tWQ goviTiiinriit n rjueriíiort of so prava ;i chnracter, and witli regañí to wl.icli ihü whnle Uritieh nntion trould bo ab'ü to cMiU-rt.iiu suyli uuauiíuit of t'oolrlcr Miijist'.-; governraent, therefore, trust tliut, wbcn tlu iDuttcr sliall Lave becn broulit uutl'T tlio cons'doratioji ot' tho govci'iiuicnt oí tin1 ünited Siate, that guvemmeiit will, of ita own accord, oü t to tlie 1 i i t i.sli govcriiniont aiicli rcdi-.'ss as alone c uld Bftticfy llic Britiuh uation, eauicly; Th' liberation of 'ie fonr gentlemen and the'.r deticery to yoiir I rdsh , in order that the m 'y tt'iin be placed Under i' prvíeciuii, and u tuiUtble apofagij fur the ajffrttsion whtch es hem commitlsd. SbouUl tliOHu tcriüs nol hú uffurcd by Mr. Suward, you will pruposo tlicm to ; h 111Yon aro ot liberty to rcad thia dispatch , to tbo Sccretary of Stato, and, if lio j shall deaire it, jou will give kim a copy ! , ol it, I un. ■! , RT7SSELL. To Th Loi -.1 1 yon, K. C. B , e , de , Aa.