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MOVEMENT 



apparatus, as depicted in Fig. 197, for carrying on an 

 artificial circulation, was employed ; but the whole of 

 it was obliquely inclined and secured to a bevelled 

 cork by means of modelling wax. The heart, Fig. 199, 

 was then placed on a horizontal stand resting on one 

 of its surfaces, while the other was freely exposed to 

 view, so that the pulsation might be examined. 



To prove our point, it must be shown that, when 

 a solid body is pressed against the ventricular wall 

 with a certain amount of force, the latter, during a 

 condition of relaxation, is indented, and allows the 

 solid body to sink into the hollow thus formed ; and 



Fig. 199.— Experiment for showing by chronophotography the mechanism of cardiac 

 pulsation. 



that, on the other hand, during systole, the ventricles 

 repel this body, and efface the depression. 



For this purpose a small square of cork (M, image 

 2) is allowed to rest on the surface of the ventricles, 

 and a lever with a counterpoising disc is balanced on 

 the cork. The ventricle receives an indentation from 

 the external pressure, and the cork partially disappears 

 within the depression, as shown in the first position of 

 Fig. 199. 



This is because the diastole of the ventricles is in 

 process of operation, as may be recognized by the 

 absence of the jet of arterial blood. In position 2 



