Epidemics. 253 



this organ or special function, and the other to a distinct 

 function or different organ? 



But it will be said that the lungs are viewed by some, 

 especially by Dr. G. Johnstone, as the centre of evil in 

 choleraic poison. Upon this theory much may be said ; but 

 in the midst of so much controversy one important point 

 appears to be lost sight of namely, that our physiology, in 

 relation to sympathy between the heart and lungs, is scarcely 

 sufficiently recognized. A man is very weak; he goes 

 upstairs ten steps, each five inches deep, and he breathes 

 rapidly and oppressedly. Another has dilatation of the right 

 side of the heart, but is not wasted in flesh ; but let him do 

 the same feat, and he breathes just as bad. A third has a 

 large frame, and no excess of fat, but altogether a feeble 

 heart ; with the same feat he has the same difficulties. 



The cause is said to arise from either a deficit of blood 

 to the head, or unequal distribution of blood to the lungs. 

 But the change in the breathing is so instantaneous and so 

 very decided, that the changed quantity of blood in the 

 lungs in so short a time cannot possibly affect it, and 

 certainly it is not from increased quantity in the lungs, as in 

 congestion ; for it is from very carefully repeated observa- 

 tions, running over many years, that the conclusion is 

 arrived at, that the proportion of blood in the lungs between 

 rest and motion, or walking on flat and rising ground, as 

 the true factor of the hurried respiration, is a pure myth. 

 Why the heart suddenly increases its rapidity - at both 

 ventricles, when the body is raised, belongs to the function 

 of the heart alone; but why increased action in the respiratory 

 muscles, and also increased respiratory action in the air 

 cells is superadded, is truly a reflex excito-motory act, and 

 of such a nature that it is impossible to affect the heart 

 specifically in its motion without the entire respiratory 

 system going along with it; the heart, upon the whole, acting 



