LESSON XIV. 

 BLOOD PRESSURE. 



A. MINOR ARTERIAL SCHEME*. 



1. Clamp the india-rubber tube at its proximal end 

 close to the pump, and leave the glass tube open 

 so that all the water flows through the latter. 

 "Work the pump with a uniform force at about 

 30 to 40 strokes a minute. To ensure regularity, 

 the strokes had better be timed with a metro- 

 nome. The water will flow from the open mouth 

 of the glass tube in jerks, corresponding to the 

 strokes of the pump. At each stroke as much 

 will issue from the distal end as enters at the 

 proximal end. 



2. Introduce into the open mouth of the glass tube 

 a fine nozzle, so as to offer considerable resistance 

 to the outflow of fluid. Work the pump with 

 the same force and frequency as before. The 

 outflow will still be intermittent, though less 

 fluid will issue from, and consequently less enter 

 into, the tube at each stroke. 



1 See Appendix. 



102 



