Grease and flour Bundt pan. In large bowl, cream butter, vegetable shortening, sugar, eggs, cream of tartar and flavoring until fluffy. Sift flour, baking powder and salt. Add to butter mix. Alternate with milk. Add lemon juice and lemon peel. Beat three minutes. Bake one hour or until toothpick comes out clean. Cool cake 10 minutes in the pan before inverting onto platter to complete cooling.
