LETTERS TO BROTHER JOHN. 63 



whole course, there are little knobs situated upon 

 it,' at short intervals ; so that it has something the 

 appearance of a cord with beads of different sizes 

 strung upon it or of a chain or of a small knotted 

 rope, with its two extremities joined so as to form 

 a sort of necklace, as it (the necklace) hangs round 

 a person's neck, falling gradually to a point in 

 front. The upper part of the chain encircles the 

 base of the brain, as the upper part of the necklace 

 encircles the neck ; and then descends on either 

 side of the spine, as the necklace descends on either 

 side of the front of the chest ; and then the two 

 descending portions are united at the extreme 

 point of the spine below. From the little knobs, 

 or ganglia, numerous nerves are given off, which 

 unite with almost all the nerves coming off from 

 the brain and spinal marrow ; and sending nume- 

 rous filaments, also, to the organs concerned in nu- 

 trition ; as the heart, lungs, stomach, bowels, liver, 

 &c. &c. Thus, whether the sympathetic arises 

 from the brain or not, it is manifest that it is 

 intimately connected with those which certainly do : 

 and as the question is not yet settled, I have 

 chosen to consider it as arising from the brain, in 

 order that your notions of the functions of the ner- 

 vous system may be as simple and little perplexed 



