Chap. XII. ASTONISHMENT. 283 



be accounted for by mucus accumulating within the tube, 

 and the consequent exclusion of air. We may therefore 

 infer that the mouth is not kept open under the sense 

 of astonishment for the sake of hearing sounds more 

 distinctly; notwithstanding that most deaf people keep 

 their mouths open. 



Every sudden emotion, including astonishment, 

 quickens the action of the heart, and with it the respira- 

 tion. Xow we can breathe, as Gratiolet remarks 7 and as 

 appears to me to be the case, much more quietly through 

 the open mouth than through the nostrils. Therefore, 

 when we wish to listen intently to any sound, we either 

 stop breathing, or breathe as quietly as possible, by open- 

 ing our mouths, at the same time keeping our bodies 

 motionless. One of mv sons was awakened in the night 

 bv a noise under circumstances which naturally led to 

 great care, and after a few minutes he perceived that his 

 mouth was widely open. He then became conscious that 

 he had opened it for the sake of breathing as quietly as 

 possible. This view receives support from the reversed 

 case which occurs with dogs. A dog when panting after 

 exercise, or on a hot dav, breathes loudlv; but if his at- 

 tention be suddenly aroused, he instantly pricks his ears 

 to listen, shuts his mouth, and breathes quietly, as he is 

 enabled to do, through his nostrils. 



When the attention is concentrated for a length of 

 time with fixed earnestness on any object or subject, all 

 the organs of the body are forgotten and neglected; 8 

 and as the nervous energy of each individual is limited 

 in amount, little is transmitted to any part of the system, 

 excepting that which is at the time brought into ener- 

 getic action. Therefore manv of the muscles tend to 



7 ' De la Physionomie,' 1865, p. 234. 



8 See, on this subject, Gratiolet, ibid. p. 254. 



