Put in a vessel half a pound of butter, with half a pound of powdered sugar. Grate in the rind of half a lemon, and with the hand knead well for twenty minutes. Break into a plate five whole raw eggs; add gradually and carefully, kneading sharply with the hand for ten minutes longer. Now add half a pound of well-sifted flour, mixing the whole slowly and thoroughly for five minutes more. Butter a two-quart, round cake-mold, and line it with brown paper at the bottom and sides. Fill it with the preparation, and put it in a slow oven to bake for fully one hour. Remove, and let cool off for about two hours.