204 LETTERS TO BROTHER JOHN. 



force by which the blood is propelled from the heart 

 through the whole of these three portions of the 

 system, back to the heart again, is the contractile 

 power of the heart and large arteries. When, 

 therefore, this power of the heart and large arteries 

 is feebly exerted, as during inaction, although it is 

 sufficiently strong to carry the blood to the ulti- 

 mate tissue, it is nevertheless not strong enough to 

 carry it through it ; at least, not to carry it through 

 with the same rapidity with which it is brought to 

 it. The result is evident : the ultimate tissue being 

 thus filled faster than it is emptied, there must 

 accrue accumulation ; that is, congestion in the deli- 

 cate and most important vessels which compose this 

 tissue ; and also in the larger veins, whose office it 

 is to convey the blood from this tissue to the heart. 

 For if the propelling power of the heart and larger 

 arteries be but feebly exerted within the tissue 

 itself, it must be still more feebly exerted on vessels 

 which are situated beyond it, and, consequently, 

 farther removed from the propelling force. 



One of the chief conditions of the body, there- 

 fore, in that general ill state of health usually de- 

 nominated " indigestion " or " dyspepsia," is con- 

 gestion of blood in the ultimate tissue of our organs 

 the brain, the lungs, the spinal marrow, the sto- 



