Preheat oven to 350 degrees. Lightly grease a loaf pan. Place currants and caraway seeds in a big bowl. Sift together flour, baking soda, sugar and salt. Pour sifted mixture over currants. Add the Irish butter, eggs and milk; mix well. Mold dough into a loaf shape on a floured board, then place on greased pan and bake for one hour, or until bread tests done.