The Paris correspondent of the London Times has developed an alleged secret plot of the Red Republicans, to revive the revolutionary fever throughout Europe, and the substance of his statements is also given in the Paris _Patrie_--both accounts being evidently derived from the same source. It is asserted that the Socialists have leagued themselves together and that a secret congress of their chiefs was held in Paris on the 2d of June, where they planned a gigantic conspiracy, the ramifications of which extend to the whole of Europe, and even to the heart of Russia, where it is said to menace a terrible explosion. The motto which has been adopted is, "_Sans pitié ni merci_," and it has been resolved that all the chiefs of states shall be assassinated. It is added that in one of the numerous secret meetings held by the initiated under the presidency of the principal agents, the death of the Bonapartists was sworn, and would be the signal for the destruction of all the Bourbons, and of all their friends and supporters. The threat uttered by one of the German chiefs of the conspiracy was to the effect that "on the field of battle we shall spare no one, and we will strike down our dearest friends if they are not unconditional Communists." After indicating the dépôts of arms formed by the Communist conspirators in all the capitals where it has established seats, enumerating the means employed to ensnare the foolish and the ambitious, and, in fact, indicating all its resources and all its plans, the document informs us that the object of the conspiracy is to arrive, by means of general confusion and a sanguinary combat, at the extermination of all those who possess a foot of land, or a coupon of _rente_, and that it has sworn the oath of Hannibal against all the monarchies of Europe. _Plunder and assassination form the basis of the plan._ The document terminates thus, "The soil of Europe is undermined, so as to render a frightful catastrophe imminent." The pretended revelation is ridiculed in nearly all quarters. On the destruction of the Roman Republic, the Roman Representatives appointed a National Committee, of which Mazzini was the head, with extensive political powers. This committee has just issued an address, dated at London, calling on all Italians and all Italian provinces to join their standard, promising them eventual success. In the course of the address they declare that they have effected such an organization of the forces of the movement as circumstances permit, and insist on the necessity of Italy becoming an independent nation.