I shall not attempt to describe these pictures, because I feel sure that no words of mine could express the transformation which the human face undergoes in pain. Even had I the talent and the pen of a great artist or a great writer, I should yet refrain, for I know that every description is useless, pale, and vague when confronted with reality. Instantaneous photographs are the best means of showing how even the greatest painters and sculptors have fallen far short of reality, in their representations of the spasms and sufferings which disfigure and distort the human face. VII The expression of pain alters according to age; it is different in the child, the youth, the adult, and the old. Energy of will or weakness of character also exercise a profound influence upon it. I have been present at surgical operations, and have performed them, on persons who refused to be chloroformed, and have noticed how great was the difference of conduct. An old officer, who bore the operation of lithotomy without anæsthetics, only clenched his hands and his teeth, keeping his eyes closed and his face almost impassive. A labourer, whose foot had to be amputated, frowned during the operation, and tapped lightly with curved fingers on the coverlet. There are patients who gnash their teeth, others who roll their eyes upwards, others again who puff; some say, before the operation begins, that they would lie still if only they were allowed to scream. But none, whatever be the strength of will, succeed in suppressing completely the expression of pain when intense. Only very energetic persons succeed in preserving immovable the muscles of the face, while they discharge the activity of the nervous system into other muscles by tetanic contractions. We may say that every malady has its peculiar expression of pain. Often, by merely looking at the patient and hearing him moan, the physician can tell which are the affected organs. This study is very much complicated because of the rare occurrence of simple sensations of pain. Our states of mind are so variable and so complex, that the expression of the face is, as it were, the result of numerous factors. To be convinced we need only think of the touching sight of a woman about to become a mother. Notwithstanding the pangs that torture her, in spite of the indescribable agony of the most intense pains to which human nature is condemned, she yet finds a smile which expresses the hope of surviving, and the joy of motherhood shines in the tender radiance of her eyes, beautifying the face furrowed by cruel suffering.