Put the yolks of four eggs in a small basin with four ounces of pounded sugar, on which you have grated the peel of one good fresh lemon; work this well with a spatula for five minutes; after which, beat up the whites of the four eggs, and when they are very stiff, pour a fourth part of them on the yolks, which you afterwards mix with the remainder of the whites, with the addition of two ounces of sifted flour, stirring continually, to make the whole very smooth.
Then form your biscuits on half sheets of white paper, folded in such a manner that they are only three inches in length, and no larger than your finger. As soon as one sheet is full, cover your biscuits with fine sugar, and place on a baking-plate, which you put in the oven as soon as the surface of the biscuits become glossy by the melting of the sugar. Bake in a moderate oven, and when they have acquired a fine colour take them out; when sufficiently cool, remove from the paper by moistening the opposite side, or with the blade of a very thin knife. Place them afterwards two and two, with their backs to each other, in order not to injure the glossy sides.