New York, July 12. The Paris correspondent of the Morning Adverti&er says the negotiations for mediation are merely brought to a stand on the slavery question, and proposals acoeptable to Richmond and objectionable to Washington, will be made shortiy- Great Britain. - The authorities of Liverpool refused a clearanoe to the steainer Gibraltar, late Sumpter, unless sonie large Blakely guns were unloaded from her. Mr. Peacock, in the Commons donounced the interruption of trade with Mutamoras by the Federáis. The Solicitor General said thera was no fault to find with the findinga of the prize courts Lord 11. Cecil denounoed the Federal prejudiees of the governtnent and complained of the prize courts. Mr. Cobden reiterated the general ob jeotions to bloekade, and thought the ruling of the judge in the case of the Alexandria would prove disastrous. The Times anticipa tes hostilities with Japan. Latest. - Karl Russell announced in Parliaraent that Baron Gros assured him that Franee had no inlention of positig mediation measures to Ümgland. Mr. Layard stated the ciroumstances under which a clearance was refused to the steamer Gibraltar, but the guns were not suitable for arming her and she is allowed to go. She is expeoted to sail on the lst. Mr. Roebuck moved his resolution in favor of recognition of the South. Lord E. Montague moved an amendment for continued neutrality. Mr. Gladstone opposed the motion and favorcd non-interveution. He believed the restoration of the Union impossible. Mr. Bright bitterlv attaoked Roebuck, and reiterated his argument in favor of the North.