Put into a saucepan the butter; when it is melted stir in the flour and let it cook a minute (but not color), stirring all the time; add one half cupful of milk slowly and stir till smooth, then add salt and cayenne. Remove from the fire and add, stirring constantly, the beaten yolks of three eggs and the cupful of grated American or Parmesan cheese. Replace it on the fire, and stir until the cheese is melted and the paste smooth and consistent (do not cook too long, or the butter will separate). Pour the mixture on a buttered dish and set away to cool. When ready to use, stir into it lightly the well-beaten whites of the three eggs; turn it into a pudding-dish and bake in a hot oven for twenty to thirty minutes. Do not open the oven door for ten minutes; do not slam the oven door; do not move the souffle until after fifteen minutes; serve it at once when done. Like any souffle, it must go directly from the oven to the table, or it will fall.