In a medium-sized pot, mix together the blueberries, water, sugar and allspice. Cook over medium heat. In a bowl, combine into a soft dough the flour, baking powder, salt, butter and milk. When there is plenty of juice on the berries, lower the heat and drop the dough mixture by tablespoonfuls onto the berries. Cover the pot and cook for 15 minutes without removing the cover. Serve with whipped cream.