MOVEMENTS OF THE HEART. 189 



rently confirm those of Drs. Pennock and Moore. Some 

 experiments made by the author a few years ago, published 

 in the " American Journal of Medical Sciences," Oct. 1861, 

 had apparently the same result. There is no doubt that the 

 point of the heart is protruded during the ventricular systole, 

 as the experiments referred to conclusively prove ; but the 

 author was led by the perusal of recent experiments by Chau- 

 veau and Faivre, to recognize the fact that this protrusion is 

 probably due to other causes than the elongation of the ven- 

 tricles, and that during the systole the ventricles are short- 

 ened. The experiment cited by these eminent physiologists 

 is very simple and conclusive. It is made by suddenly 

 cutting the heart out of a warm-blooded animal, and watch- 

 ing the phenomena which accompany the few regular con- 

 tractions which follow. They found that the ventricles 

 invariably shortened during the systole. This could easily 

 be appreciated by the eye, but more readily if the point 

 of the organ were brought just in contact with a plane 

 surface at right angles, when at each contraction it is 

 unmistakably observed to recede. 1 This experiment we 

 have lately repeated before the class of the Bellevue Hos- 

 pital Medical College, and have satisfied ourselves of its 

 accuracy. A large Newfoundland pup, about nine months 

 old, was poisoned with woorara, artificial respiration was 

 kept up, and the heart exposed. After showing the protru 

 sion of the point and the apparent elongation while in the 



sanne, 1760, tome Hi., p. 224) ; but in experimenting on the organ after excision, 

 the position in which it is held is important. If, for example, we take the heart 

 of a turtle between the thumb and finger and hold it with the point upwards, the 

 ventricle is so thin and flabby that it will become flattened during the intervals 

 of contraction, and the point will be considerably elevated at each systole ; but if 

 we reverse the position and allow the point to hang down, it will be drawn up and 

 the ventricle will shorten with the systole. 



1 CHAUVEAU et FAIVRE, op. cit., p. 14. These observers show the shorten 

 ing of the heart during its systole by holding it by the great vessels with the point 

 down. It is more free from sources of error to observe the phenomena as the 

 heart lies on a flat surface. 



