Preheat oven to 325 degrees F,165 degrees C. Grease and flour 2 round 8 inch pans. Sift the flour and salt together and set aside.Beat butter and sugar until light and fluffy. Add eggs and mix well. *Dissolve baking soda in buttermilk. Alternately add flour and buttermilk, beginning and ending with the flour. Pour into two 8-inch pans. Bake at 325 degrees F (165 degrees C) for about 30 minutes, or until toothpick inserted into cake comes out clean. Cool cake completely before icing.