Scald the milk and add the butter. When it grows luke warm, add the yeast dissolved in three tablespoonfuls of warm water. Add the salt and flour, and beat well for about ten minutes. Set in a warm place over night. In the morning beat the yolks of the eggs well, then the whites to a stiff froth; add the yolks and beat well, then add the whites, and mix all thoroughly. Beat till very light, let stand for about a quarter of an hour, and then bake in a buttered pan for about twenty minutes in a quick oven.