In a bowl mix together flour, salt, sugar and baking soda. With your fingers, crumble in the butter. Add in raisins and caraway seeds and pour in buttermilk until dough is no longer dry but holds it's shape when formed into a round. Place in a greased round baking dish or free formed on a cooking sheet and cut a deep cross in the middle. Bake for 40-50 minutes until golden brown.