PERFUSION 75 



a. Pure sodium chloride -65 p.c. The heart becomes 

 weaker and gradually stops in diastole. Perfuse with 

 Ringer's fluid, the heart recovers. 



b. Sodium chloride -65 p.c. + potassium chloride 1 p.c. 

 The heart-beats become weaker and rapidly stop in 

 diastole. Perfuse with Ringer's fluid, the heart recovers. 



c. Sodium chloride -65 p.c. + calcium chloride -2 p.c. 

 The tone of the heart increases, and the heart beats at 

 a higher level. Add a little 1 p.c. CaCl 2 , the heart stops 

 in systole. Perfuse with Ringer's fluid, the heart re- 

 covers. 



