Page:Popular Science Monthly Volume 4.djvu/577

Rh, they might in like manner give us graphic representations of its motions under the influence of the various passions, such as love, fear, grief, joy, anger, etc. Indeed, each of these states of the soul produces, in the order of the heart's beatings, a modification so peculiar and characteristic that we may regard each of the passions as having a curve of its own. M. Cyon, who has recently suggested this ingenious idea of applying graphic apparatus to the physiology of the passions, gives some illustrations of the bearings such experiments might have. Among the heirs gathered round the bed of a dying man there is one whose grief causes his heart to beat slowly but violently. In some of the others, who impatiently await the end, the heart beats quickly but feebly. The graphic apparatus, which describes, with marvelous precision, the rhythm of cardiac contractions, and which is called the cardiograph, could in this case exhibit the real feelings of the heirs. This is not at all an exaggeration, and we have no doubt that an instrument of great sensibility could be got to note the differences here referred to. Perhaps the case would be different under circumstances of greater complexity. The modifications of the heart's beating intervene in a twofold manner, in the determination of our inclinations and in the acts which proceed from them, either by producing sudden changes in the quantity of blood diffused through the nerve-centres, or by giving us agreeable or painful sensations through the depressor nerves. Now, a sudden afflux of blood to the brain, and extremely painful sensations, may produce, in a man not suffering from any mental disease, the craziest notions, and may betray him into the commission of the most serious offenses. Suppose a man commits a crime under circumstances but ill understood; the question arises, Was he moved to the act unconsciously and by physiological causes, or did he do it designedly and after calm reflection? M. Cyon thinks he can resolve this problem as follows: The soul possesses the faculty of experiencing, on the recollection of a past act, emotions of a like kind with those it experienced at the moment of its commission. The detailed history of a crime must produce in the accused who listens to it—supposing that he had committed the crime knowingly—emotions of this kind, as also the cardiac motions necessarily correlative to them. Hence the judge may, by means of the cardiograph, inform himself as to the presence or absence of these motions, and so decide whether the accused has or has not a recollection of the crime, i. e., has committed the crime whether with or without consciousness. This instance is rather ingenious than plausible, rather theoretic than practical. Of course, an individual who has committed a crime in a state of delirium cannot, on hearing the history of that crime, experience the same emotions, nor consequently the same modifications of the heart's movement, as he would if he had committed it with a full knowledge of what he was doing; still, it would be as hard for him in the one case as in the other, to maintain an absolute sang-froid. A man who is