Beat the whites of the eggs to a stiff froth. Add the baking powder and salt to the flour, and sift it three times. Sift the sugar three times. Beat the butter which has been well washed, to a cream with the sugar. Then gradually add the flour, beating all the while, and the flavoring Extract. Lastly, add the whites, which must be very stiff. Mix all thoroughly and bake for half an hour in a moderately quick oven. Use a Turk’s head tin.