14 LETTERS TO BROTHER JOHN. 



just seen from whence from the brain. But this 

 is a paradox ! It is so ; yet it is true. 



The heart cannot send blood to the brain, till it 

 has been stimulated to do so by the brain ; and yet 

 the brain cannot elaborate the fluid by which it 

 stimulates the heart to motion, until it has already 

 received blood from the heart from which to elabo- 

 rate it, and by which it is itself nourished and 

 supported. The fact is, that the heart and brain 

 act on " the reciprocity system " : neither can do 

 without the other. Their reciprocal influence 

 moves in a circle. Neither can begin ; both must 

 exist simultaneously ; and the instant one dies, the 

 life of the other is extinguished. It is in vain to 

 seek the origin of this motion, by tracing it back- 

 ward : we only get from the heart of the embryo 

 to the heart of the parent from the brain of the 

 embryo to the brain* of the parent. Where, then, 

 are we to look for the origin of this motion ? 

 There is but one source, my dear John, of all 

 motion, and all emotion. The motions in our 

 physical organs, as well as those which sustain the 

 planetary system, those which constitute chemical 



* It will be clear to the physiological reader, that I have here 

 used the word brain to represent the whole cerebral root the 

 brain, spinal marrow, and great sympathetic ganglionic system. 



