CREATE TABLE table_25103 ("District" TEXT, "Vacator" TEXT, "Reason for change" TEXT, "Successor" TEXT, "Date successor seated" TEXT)

Name the vacator for resigned february 26, 1836 because of ill health
SELECT "Vacator" FROM table_25103 WHERE "Reason for change" = 'Resigned February 26, 1836 because of ill health'
SELECT "Vacator" FROM "table_25103" WHERE "Reason for change" = 'Resigned February 26, 1836 because of ill health'