Mix flour, baking powder, salt and sugar with butter (or shortening).
Beat an egg white until stiff.
Take the milk and blend it with the egg white.
Mix dry mixture with the milk.
Knead this mixture on a flat surface liberally dusted with flour then roll out into a rough square ½ an inch thick.
Cut into triangles approx 5” in length. Use lots of flour on the bottoms so they don't stick to the pan..
Lightly dust a non-stick pan with flour, and brush egg yolk on top of scones for a glaze.
Bake at 375 for 20-25 minutes until they are golden brown.