Blueberry Muffins

1/3 cup butter
3/4 cup sugar
1 egg beaten lightly
1 cup milk
2 level cups fluor
4 level tsp baking powder
1/2 tsp salt
1 cup blueberries

Cream butter and sugar. 
Add fruit and egg, then milk and fluor sifted with baking powder and salt.
Bake in muffin tins in hot (425ºF) oven for 15-20 minutes.