560 THE POPULAR SCIENCE MONTHLY. 



accused of having committed a crime, and who knows that he has 

 committed it, is alarmed at the sight of the judge who questions him, 

 and at the thought of the accusation which stands against him, even 

 though the crime was committed in a moment of delirium. On the 

 other hand, it may easily happen that a hardened malefactor, who has 

 committed a crime with full deliberation, will be so far master of him- 

 self as to feel but insignificant emotion when the circumstances of his 

 crime are brought up before him. Yet this idea of M. Cyon's merits 

 the attention of psychological physiologists, and we may venture to 

 hope that the day will come when treatises on psychology will con- 

 clude their descriptions of passional states with graphic tracings show- 

 ing the rhythm of heart-contractions which answers to each passion. 

 These tracings will be trustworthy and precise, for, if the will be mis- 

 tress of movements and demonstrations that appear at the surface, it 

 has but very little power over viscera that are concealed, like the 

 heart, and these are truthful witnesses, ever at hand to rectify lying 

 testimony. 



II. 



But we must bear in mind that muscles which are subject to 

 the will are not always employed to dissemble passion, but that very 

 often, by their almost automatic attitude, they betray the real state of 

 the feelings. In vain would a man in a furious passion strive to stand 

 still. All his members are agitated with violent movements. Aston- 

 ishment produces a relaxation of the muscles, and hence the French 

 phrase, les bras tombent (the arms fall), to denote the effects of this 

 emotion. Fear causes one's legs to fail him ; one is said to bepetrified 

 by fear. But there are none of the muscles that are so influenced, so 

 modified by the passions, as those of the face. The physiognomy is 

 indeed a betrayer of the soul's inner states. " When the soul is agi- 

 tated," says Buffon, " the face becomes a living picture, wherein the 

 passions are given with equal delicacy and force ; where every move- 

 ment of the soul is expressed by a dash of the pencil, and each act by 

 a character, the rapid, liviug impress of which outstrips the will, thus 

 unveiling and manifesting, by passionate signs, our most secret emo- 

 tions." 



It seems impossible to subject to physiological analysis appearances 

 so complex, so varied, and so fickle. And yet an accomplished experi- 

 menter has recently succeeded in partially ordering this chaos, and in 

 precisely determining the muscular mechanism of the human physiog- 

 nomy as related to the various passions. Having first ascertained, by 

 minute dissections, the position and separate function of the numerous 

 muscles situate between the skin and the facial bones, and having 

 learned how the nerve-filaments of the seventh pair (the facial nerves) 

 are distributed through these muscles and animate them, M. Duchenne, 

 of Boulogne, has determined, by means of the electric current, or of 



