Beat yolks of eggs until lemon-colored. Add sugar, salt, and rum. Cut and fold in whites of eggs beaten until stiff and dry. Butter a hot omelet pan, pour in one-half mixture, brown underneath, fold gradually, turn on a hot serving-dish, and sprinkle with powdered sugar. Cook remaining mixture in same way. Soufflé au Rhum should be slightly underdone inside. At gentlemen’s dinners rum is sometimes poured around soufflé and lighted when sent to table.