LETTERS TO BROTHER JOHN. 69 



your body without producing pain and bleeding ; 

 which proves that the point of the needle has 

 wounded both a nerve and a blood-vessel. 



We have seen that the nerves all arise from, or 

 are, at least, intimately connected with the brain 

 and spinal marrow; and we have seen that the 

 spinal marrow is but an elongation of the brain. 

 Now we all know what a powerful effect the emo- 

 tions, such as fear, anger, &c., have in depressing 

 and exciting the brain's action. Considering, there- 

 fore, that all the organs of the body derive their 

 power of action from a fluid brought to them by 

 the nerves from the brain, by whose action that 

 fluid is produced, it is easy to comprehend how 

 it happens that moral causes can exert so momen- 

 tous an influence on the health. 



Sis memor mei ! 



E. JOHNSON. 



