Lemon Pie

One cup of powdered sugar, one teaspoon of butter, one egg, one lemon, juice and rind, removing the seeds with care; one teacup of boiling water, a tablespoon of corn starch disolved in cold water; stir the corn starch into the water; cream the butter and sugar, and pour over it the hot mixture, and when quite cool add the lemon and beaten egg, and bake upon a plate covered with, paste. For frosting, take the white of one egg and powdered sugar to make it sufficiently thick to cover well.