The eye examines the human countenance with such rapidity and such accuracy that no one will ever succeed in giving in words a picture of the minute details and fugitive traits which we see appear and disappear on the face during emotion. Even the greatest masters were not very exact in such-like descriptions, and had recourse to similes, to flowery and metaphorical language. If, for instance, we write that someone looked at us in astonishment or fear, we indicate an endless series of gradations of the same feeling, differing one and all from each other in intensity and effect, and we leave it to the judgment of the reader to choose that which seems to him best suited to the instance, without our having the means to demonstrate it to him. When we say to a friend, 'I must give you a piece of bad news,’ there appears a sudden change in his face, his look and his gestures, which touches us. But there is no art of words capable of describing it, because we cannot measure the imperceptible changes which take place in the movement of the eyes, the widening of the pupils, the colouring of the cheeks, the trembling of the lips, the dilatation of the nostrils, the acceleration of the breath, the gestures of the hands, the attitude of the head and trunk. Certain fine characteristic traits of the face disappear under the magnifying glass like the diamond burning away in the crucible. The aspect of the countenance is impalpable; its beauties are covered by a subtile, delicate veil, which we cannot touch without tearing it and destroying the charm. It is on this account that I stretch out my hand hesitatingly to take hold of the scalpel and lay bare the head of a corpse, in order to cut through the skin and detach the muscles. When I have separated the muscles of the face from the bones of the skull, a mask like a funnel of flesh remains in my hand. Oh, how ugly is the human face seen from the wrong side! We do not recognise ourselves; we cannot believe that this fibrous web and muscular network represent the most beautiful and expressive part of the organism; that this is the face formerly so graceful in its movements and play of feature, so inexhaustible in its expressions of benevolence and affection. It is a thorough disillusion, a sad sight, as when one sees the framework and the burnt-out rockets of fireworks in broad daylight, or when, at the end of the play, we examine near-to the daubs and rags of a dazzling theatrical decoration. We cannot believe that it is this fibrous flesh which lends us the aspect, the characteristic traits, the expression of our ego; that it is on this thin leaf of muscle that each writes his life-story; that it is the chance arrangement of these parts which impels us to mysterious sympathies, to indifference, antipathy, repugnance; that it is the unfathomable secret of these organs which unconsciously draws men together or apart, like atoms that meet, separate, or remain indissolubly united. II