'Thus it happened that he sickened most seriously through excess of passion. Then were several physicians called to restore him, but, despite their careful watching, they could not guess his disease, and despaired of his recovery. And so it came to pass that one day, while a physician, still young indeed, but of profound science, sat near the patient, holding his arm there where the pulse beats, Giannetta came for some reason into the room where the youth was lying, who, when he saw the maiden, did not indeed betray his emotion either by word or gesture, but felt the ardour of passion increase in his heart, wherefore his pulse began to beat more violently than before. This the physician incontinently noticed and wondered, but remained still to see how long these pulsations would continue. When Giannetta left the room, the pulse became calmer. The physician, now deeming he had discovered the reason of the malady, caused the maiden to be called on the pretext of having a question to put to her, he still holding the patient by the wrist. Scarcely had she come into the room than the youth’s pulse beat more rapidly, slackening once more at her departure. Whereupon the physician, believing himself in possession of the truth, arose, and taking the parents of the young man aside, said to them: “The health of your son needs not the physician’s art; it lies in Giannetta’s hands.”’ So Boccaccio describes the diagnosis of the illness of the Count of Antwerp; and long before Boccaccio, Plutarch had already stated that the physician Erasistratus discovered the love of Antiochus to Stratonice from the tumultuous irregularity of his pulse. We here touch upon one of the greatest problems which criminal science will propound in the future, when it asks the physiologist: 'Tell us of what does this man think, who remains impassive before the traces of his crime? Tell us if within him there is nothing pulsating--nothing, either human or animal?’ [Illustration: FIG. 3.--CURVE SHOWING CARDIAC PULSATIONS OF A QUIET DOG]