LEMON SAUCE

Mix ½ cupful of sugar and 1 tablespoonful cornflour or arrowroot with a little water (cold), stir in carefully 1 cupful boiling water, and cook for 10 minutes, stirring often. Add more boiling water, if too thick. Stir in the grated rind of one lemon, also the juice of one lemon and 1 tablespoonful of butter. Remove to the back of the stove, and stir in quickly the well-beaten yolk of 1 egg. Beat the white very stiff and put it in lightly, leaving parts of it in little lumps, which give a very pretty effect.