Cream sugar and butter. Add egg yolks. Beat thoroughly. Sift flour, measure, and sift with baking soda and salt. Combine sifted dry ingredients and 1/2 cup sour milk with first mixture. Combine 1/2 cup sour milk with cocoa and heat over hot water until cocoa is melted. Cool. Add to cake batter. Add raisins, which have been dredged in 2 tablespoons of the flour, and nuts. Mix thoroughly. Fold in stiffly beaten egg whites. Pour into well-oiled layer cake pans. Bake in moderate oven (375 F) about 25 minutes. Ice with mahogany icing. Mrs. R.B. Bumgartner, Adona, Ar.