Preheat the oven to 350 degrees. Grease and flour the bottom and sides of a 10-inch tube or Bundt pan. Set aside.
In a large bowl, cream the butter and sugar together at medium speed until light and fluffy. Add the eggs, one at a time, beating well after each addition.
In a separate bowl, sift together the flour, baking powder and salt. In yet another bowl, combine the milk, extract, lemon juice and zest. Add the dry and wet mixtures alternately to butter mixture, beginning and ending with the dry.
Fold in the blueberries. Spread the batter into the prepared pan. Bake 50-60 minutes or until a tester inserted in the center comes out clean.
Cool 10 minutes in the pan, then turn out onto a wire rack and cool completely before slicing.