Chocolate Icing.
Make the white icing. Shave one ounce of plain chocolate and put it into a small pan with three tablespoonfuls of powdered sugar and one of boiling water. Stir over a hot fire until smooth and glossy, and then stir this into the icing. If it seems too thick, add a few drops of water.
Do not use the lemon in the white icing when the chocolate is to be added.