. 57 



the ventricles fnto the veins, and from the arteries 

 into the ventricles, In a healthy person, the heart 

 contracts little less than five thousand times in an. 

 hour. 



36. The Heart is covered with a fine membrane; 

 and near the base of it, on the outside, there is a little 

 fat, probably designed to facilitate its motion. It is 

 placed near the middle of the breast t only its cone 

 inclines a little to the Lett. It hangs by its base on 

 vein sand arteries, communicating with all parts of the 

 body. The other part of it is loose in the pericar- 

 dium, that it may be the more commodiously constring- 

 ed arid dilated. The pericardium is a kind of raenv 

 brane that like a kind of purse, loosely incloses the 

 heart. The shape of it is suited to that of the heart^ 

 and it contains a thin, saltish, reddish huinour,exuding 

 from the arteries. 



The brain has an alternate contraction and dilation, 

 answering those of the hi-art. It is highly probable, 

 the weight of the atmosphere is the counterpoise to 

 the contractile force of the heart. That of the brain, 

 being not near so strong, does not need so strong a 

 Counterpoise. * 



In the basis of the heart, in some animals, there is 

 a bone frequently found. Such an one was found in 

 the heart of Pope Urban. Probably it was only the 

 tendons of the heart ossified. 



Wounds of the heart are not always so immediately 

 mortal as is generally supposed. A soldier w r as brought 

 into one of the hospitals in Paris, with a wound in the 

 upper part of the left breast. He seemed very well 

 for three days : but on the fourth was taken with a 

 fever and difficulty of breathing, and died on the 

 tentl). On opening the body, it was found the sword 

 had pierced the pericardium, traversed the right ven. 

 tricle of the heart in its lower part, pierced the peri- 

 cardium on the opposite side, and gone through the 

 diaphragm, and an inch deep into the liver. 



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