LETTERS TO BROTHER JOHN. 103 



improper to mention them in a letter like this. We 

 know, too, that when any one part of the body is in 

 great pain, the rest of the body is nearly insensible 

 to lesser pain. This fact has given rise to a curious 

 operation for the cure of traumatic locked-jaw. It 

 consists in inflicting on the wretched patient, in 

 some part of his body, a pain, the anguish of 

 which shall be greater and more excruciating than 

 the tetanic agony : thus, as it were, restoring the 

 equilibrium of the sensibility; and subduing a 

 great pain, by inflicting, for the time, a much 

 greater pain. The operation is said to have been 

 successful : but the operators complain, that they 

 can get few patients to submit to it. Sensibility, 

 then, can be drawn from one part of the body, and 

 concentered in another. 



Another curious circumstance connected with 

 SENSIBILITY is SYMPATHY. All the organs of the 

 body appear to sympathize with one another. That 

 the brain and stomach have a strong sympathy 

 with each other, is absolutely certain : the proof of 

 which is, that a violent blow on the head will 

 produce vomiting ; and a deranged state of the 

 stomach will produce headache. Whatever, there- 

 fore, affects your stomach injuriously, will also 

 affect your brain injuriously. He, therefore, who 



