INVOLUNTARY MUSCLES. 487 



strong, we may not be able to refrain from willing its contraction ; 

 just as a very strong motive may involuntarily impel us to will 

 any mental operation. If you cause strong pain or titillation in a 

 person, he will be compelled, whatever restraint he may at- 

 tempt upon himself, to^ cry out or laugh, and to make an effort 

 to remove it by motion of some part. We are instinctively and 

 almost unconsciously led to will suitable motions, and if, as 

 usually is the case, we have no motive not to yield to the in- 

 clination, the motion takes place almost without the appearance 

 of our will. It is thus that we breathe and wink all day. The 

 respiratory muscles deserve the epithet voluntary as much as any 

 in the body, for we directly contract them y : we feel an uneasy 

 sensation in the chest from the retardation which occurs to the 

 blood, and we inspire to remove it; the uneasiness being re- 

 moved, our effort ceases, and expiration spontaneously ensues. 

 The necessity for sighing after reading or listening attentively 

 arises from our having forgotten to breathe fully, not having 

 fully perceived the want of breath while our attention was so oc- 

 cupied z ; and the general coughing and sneezing in church at 

 a pause in the sermon are owing to the sensations which give rise 

 to those actions having been for a time overpowered throughout 

 the congregation by other feelings. a It is true that respiration 

 continues while we are asleep, and that the uneasiness is so 

 great that we are forced to inspire. 1 * But the same is true 

 of all voluntary muscles. 



saw and observed them, deliberately and distinctly, and shall leave to the philo- 

 sophic reader to make what inferences he thinks fit ; the truth of the material 

 circumstances I will warrant." 



M. Ribes is said to have published a similar case : but I have not been able 

 to find it. 



y This is the opinion of Haller, and ably defended by him. El. PliysioL t. iii. 

 lib. viii. 18. 



z Dr. Darwin, Zoonomia, vol. i. 



a Dr. Alison's Observations on Sympathy in the Edinburgh Med. Chirurg. 

 Trans, vol. ii. 



b Opposite circumstances have an opposite effect. When the French soldiers 

 drove the Piedmontese on the tops of the Alps between St. Bernard and Cenis, 

 Parat and Martin say that the mouth and nose were involuntarily closed against 

 the storm, that all attempts at inspiration were fruitless, and, if they could not 

 oppose the blast by turning round or putting the hand to the mouth, they fell 

 down giddy and died. (M6m. de la Soc. Md. de Lyons. 1798.) 



