Sour Cream Pound Cake
["1/2 lb. butter", "3 c. sifted sugar", "1/4 tsp. soda", "1 c. sour cream", "6 egg whites, beaten stiff", "6 well beaten egg yolks", "3 c. flour, sifted 3 times", "1 tsp. each: vanilla, almond and lemon extract"]
["Cream butter; add sugar.", "Add egg yolks and beat until smooth. Sift flour with soda and add alternately with sour cream.", "Add flavoring and stiffly beaten egg whites.", "Bake in a well oiled and floured tube pan in a 325\u00b0 oven.", "After the cake has baked 25 minutes, raise oven temperature to 350\u00b0 and bake approximately 40 more minutes.", "(Do not open oven door for 1 hour after you put the cake in oven.)"]
["butter", "sugar", "soda", "sour cream", "egg whites", "egg yolks", "flour", "vanilla"]