Add butter, sugar and salt to milk; when lukewarm, add yeast dissolved in the lukewarm water, and 3 cups of flour. Beat thoroughly, cover and let rise until light; cut down and add the rest of the flour or enough to knead. Let rise again in a warm place, toss on slightly floured board, knead, pat and roll out to ⅓ inch thickness. Shape into rounds, with biscuit cutter; dip the handle of a knife in flour and with it make a crease through the middle of each piece; brush over one-half of each piece with melted butter, fold and press edges together. Place in greased pan one inch apart, cover, let rise and bake in a hot oven 12 to 15 minutes.