Sudden and severe indisposition has prevented, and may for an indefinite period continue to prevent, Ambrose H. Sevier, recently appointed commissioner to Mexico, from departing on his mission. The public interest requires that a diplomatic functionary should proceed without delay to Mexico, bearing with him the treaty between the United States and the Mexican Republic, lately ratified, with amendments, by and with the advice and consent of the Senate of the United States. It is deemed proper, with this view, to appoint an associate commissioner, with full powers to act separately or jointly with Mr. Sevier. I therefore nominate Nathan Clifford, of the State of Maine, to be a commissioner, with the rank of envoy extraordinary and minister plenipotentiary, of the United States to the Mexican Republic. JAMES K. POLK. WASHINGTON, _March 22, 1848_. _To the Senate of the United States_: I transmit herewith a report from the Secretary of State, with the accompanying documents, in compliance with the resolution of the Senate of the 24th January, 1848, requesting the President to communicate to the Senate, if not inconsistent with the public interest, the correspondence of Mr. Wise, late minister of the United States at the Court of Brazil, with the Department of State of the United States. JAMES K. POLK. WASHINGTON, _March 24, 1848_. _To the Senate of the United States_: In answer to the resolution of the Senate of the 17th instant, requesting the President to transmit to that body "a copy of a dispatch to the United States consul at Monterey, T.O. Larkin, esq., forwarded in November, 1845, by Captain Gillespie, of the Marine Corps, and which was by him destroyed before entering the port of Vera Cruz, if a communication of the same be not, in his opinion, incompatible with the public interests," I communicate herewith a report of the Secretary of State, with a copy of the dispatch referred to. The resolution of the Senate appears to have been passed in legislative session. Entertaining the opinion that the publication of this dispatch at this time will not be "compatible with the public interests," but unwilling to withhold from the Senate information deemed important by that body, I communicate a copy of it to the Senate in executive session. JAMES K. POLK. _To the House of Representatives of the United States_: I transmit herewith a report from the Secretary of State, with the accompanying documents, in compliance with the resolution of the House of Representatives of the 8th instant, calling for "any correspondence which may have recently taken place with the British Government relative to the adoption of principles of reciprocity in the trade and shipping of the two countries." JAMES K. POLK. MARCH 24, 1848. _To the Senate of the United States_: