Chocolate marble cake

1. Sifti flour once, measure, add baking powder and salt, and sift together three times.
2. Creami butter thoroughly, add sugar gradually, and cream together until light and fluffy.
3. Add flour, altemately with milk, a small amount at a time, beating afrer each addition until smooth.
4. Add vanilla.
5. Foldi in egg whites quickly and thoroughly.
6. To melted chocolate, add sugar and boiling water, stirring until blended.
7. Then add soda and stir until thickened.
8. Cool slightly.
9. Divide batter in two parts.
10. To one part add chocolate mixture.
11. Put by tablespoons into two greased 9-inch layer pans altemating light and dark mixtures.
12. Then with knife cut carefully through batter once in a wide zig-zag course.
13. Bakei in moderate oven ( 375