There is a paragraph in the Gazette of Amsterdam, of the 21st, from Paris of the 14th of April. "It is only by conjecture, that we talk of the plan of the next campaign in Europe; and it is also with the same uncertainty, that we lend our ear to the report, which runs, that the Count d'Estaing will command the combined fleet, and even, that the Count du Chaffault, as well as the Spanish Admirals, have offered to serve under him. It is pretended, besides, that there may very well be also some alterations in the progress of our Ministry, if it is true, as they continue to affirm, that the Count de Parades has been arrested as a spy of the English Government, to whom he was, in fact, in a capacity to discover important particulars upon this subject. But there is another piece of news, to which we give more credit, because, really, there is no good citizen, nor genuine friend of humanity, who does not wish to hear it confirmed. It is, that there should be, as it is said, upon the carpet, a plan concerted between all the maritime powers of Europe, to the end to form and digest a universal code for the sea, the laws of which no nation should attempt to infringe, without devoting herself to the indignation, or exposing herself to the vengeance, of all the others; an important project, if it could be executed, which would insure the happiness and tranquillity of nations, and would set bounds, which could not be passed, to the audacity, as well as the avarice of any one, which, without any other right than that of force, should pretend to arrogate to itself the exclusive empire of the sea." There is also intelligence from the Hague of the 19th of April, that there was sent on the 14th of the month to the Assembly of the States-General of the United Provinces, a Memorial of the following tenor. "Their Noble and Grand Mightinesses, the Commissioners of the affairs of commerce and navigation, conjointly with some counsellors of Holland, and Ministers of the College of Admiralty residing in this Province, having, in consequence of a resolution of the 4th of this month, examined the Memorial presented the day before to the Generality, by the Prince Gallitzin, Envoy Extraordinary of her Majesty, the Empress of all the Russias, by which the Minister has communicated a declaration made by his sovereign to the Courts of France, Spain, and England, that the neutral powers may protect by common agreement the commerce and navigation of her subjects respectively, as is more fully explained in the note of the 4th of April.