558 THE POPULAR SCIENCE MONTHLY. 



painful loss, when suddenly conveyed, oftentimes produces wild, irreg- 

 ular contractions, owing to a paralysis of the retardator nerves, and it 

 is not rare to find this disordered excitation followed by a total stop- 

 page of the heart's action, and syncope. Hence, says Claude Bernard, 

 when we have to communicate to a person some heart-breaking piece 

 of intelligence, we must use great precaution. The intensity of the 

 effects produced on the heart by the soul's emotions depends, above 

 all, on the excitability of the nerves connecting heart and brain. The 

 greater the excitability of these nerves, the more pronounced are the 

 heart's motions, and the finer, too, and the more delicate are the con- 

 secutive impressions. It is because the nerves of women and children 

 are more excitable than those of men, that their hearts also are more 

 profoundly affected by the emotions ; or, in common language, their 

 hearts are more tender, more sensitive. 



While the heart seems to be more directly under the influence of 

 the feelings, the lungs appear to have some connection with thought. 

 "When absorbed in some profound meditation, or when listening to 

 some orator whose discourse rivets our attention, we suspend the re- 

 spiratory movements. Darwin offers an ingenious explanation of this 

 phenomenon, attributing it to the habit we have contracted of not 

 breathing when we are listening attentively, so as not to disturb by 

 the sound of the breath the silence necessary for catching every syl- 

 lable. 



From the fact that the real affections of the soul, and consequently 

 of the brain, are always accompanied by disturbance of the respira- 

 tory and circulatory functions, we may conclude that the heart and 

 the arterial tension are the true index of the passional states. Hence 

 it is that the actor, when he would prove that some perilous situation 

 inspires him with no fears, seizes the hand of the one he seeks to reas- 

 sure or to convince, and places it over his own heart, in order to show 

 that the beatings of that organ keep up their usual rhythm. Hence, 

 too, it is that we must not regard outcries and gestures as positive in- 

 dices of passion. When you see a woman weeping and agitated on 

 hearing some painful news, you have only to feel her pulse ; if that 

 is normal, you may pronounce the emotion simulated. On the other 

 hand, if you see a woman whose distress is manifested by no outward 

 signs, but whose heart beats with unwonted irregularity, you may be 

 sure that she feigns a calm that is not in her soul. There is yet 

 another mode of ascertaining, and even of measuring accurately, the 

 strength of emotions. This we may do by applying either to the pulse 

 or to the heart one of those delicate apparatus invented by M. Marey, 

 which trace on a sheet of blackened paper curves of greater or less 

 sinuosity, representing the number, the force, and the form of the 

 beats of the pulse, or the contractions of the heart. Just as these 

 apparatus give us tracings which at once indicate the nature of the 

 heart's motions in various diseases, for instance, fever, typhus, or pneu- 



