Preheat oven to 325 degrees.
Butter and sugar a 8½ x 4½ x 2½" loaf pan; set aside.
Whisk together flour, baking powder and salt in a small bowl; set aside.
Using an electric mixer, cream the butter and 1 cup of the sugar together until light and fluffy.
Add eggs one at a time, beating well after each addition.
Add the lemon peel.
Slowly mix in the flour mixture alternatively adding the milk beginning and ending with the flour mixture.
Lightly coat blueberries with a small amount of flour.
Gently fold in blueberries into the batter.
Spoon batter into loaf pan.
Bake for about one hour until golden brown and a wooden toothpick inserted into the center comes out clean.
Meanwhile, bring remaining ⅓ cup of sugar and lemon juice to boil in a small saucepan, stirring until sugar dissolves.
Once removed from the oven, pierce the top of the hot loaf several time without touching the bottom of the loaf in pan.
Pour the hot sugar mixture over the loaf.
Cool for 30 minutes in pan on a wire rack.
Turn bread out of pan and cool completely on rack.