Cream butter and 1 cup sugar in bowl til light. Beat in eggs. Add milk and mix well. Sift flour, baking powder and salt into a bowl. Add to butter mixture and beat til smooth. Stir in lime zest and blueberries
Pour batter into a greased 4 x 6 inch loaf pan. Bake at 350 for 1 hour or til wooden pick inserted in center comes out clean.
Mix lime juice and 1/2 cup sugar in a bowl til sugar dissolves. Spoon over the hot bread before removing from the pan. Makes one loaf.