Soak raisins in hot water to cover until raisins are soft. In a double boiler heat milk and rice. Beat egg yolks until smooth, then add brown sugar and salt. Add milk and rice mixture very slowly, then pour back into the double boiler and cook over boiling water until very thick. Fold in beaten egg whites. Add vanilla or lemon juice; fold in drained raisins. Makes about 4 cups. VARIATION: This pudding can be cooked with a meringue top. Proceed as above; do not fold in egg whites. Instead, preheat the oven to 425 degrees F and pour the cooked pudding into a 2-quart baking dish. Beat the egg whites with 2 tablespoons powdered sugar and ½ teaspoon lemon juice. Spoon meringue over the pudding and bake for 5 minutes or until brown. Serve within 1 hour.