1/2 c. butter or shortening
1 1/2 c. sugar
3 eggs, separated
4 tbsp. cocoa
1 1/2 tsp. baking soda
1 c. milk
2 c. flour, sifted
1/4 tsp. salt
1 tbsp. vinegar

Cream shortening thoroughly. Add sugar and cream mixture. Add egg yolk and cocoa, beat. Dissolve soda and milk. Sift flour and salt together alternately add flour and milk to batter. Beat egg whites until stiff. Fold into batter. Stir in vinegar last. Put in greased and floured cake pan. Bake 30 minutes at 350.