Tub Madison Post Office.—The Wash* ingto'n correspondent of the La Crosse lie' publican, writes as follows : “There is a savage fight over the Madison post office.— 1ST. W. Dean, who is an applicant, arrived in Washington this morning. “Nat’5 is eager for the fray—no war steed was ever more so. It is supposed that Dr. Brisbane will beat both Dean and Keves,♦ai __________ ____ri_ __