152 ELEMENTARY PHYSIOLOGY. [XIV. 



measured, and the length of tubing between the 

 two levers being known, the rate of progression 

 of the pulse-wave ascertained.) 



5. While the pump is working, the clamps being 

 closed and the manometers A and V tracing 

 their curves, gradually diminish the resistance 

 by opening slowly first c' and then c". 



The arterial pressure curve will gradually fall, 

 still marked by the pulse oscillations; the venous 

 curve will gradually rise. 



Biminution of cwpillary resistance lowers arterial, hut 

 increases venous pressure. 



6. Close the clamps c' and c", and take tracings 

 with the manometers, then gradually reduce the 

 strength of the strokes of the pump. 



Both arterial and venous pressure will diminish. 



7. The clamp c being closed, the main arterial trunk 

 of the scheme divides into two chief branches, X 

 and Y, each with its own resistance and venous 

 tube. 



Leave the clamps c', c" closed, and put clamps 

 on the tubing immediately beyond x and y. 



a. Work the pump with great regularity, and 

 measure the quantity of fluid which escapes 

 during a given time (say ten seconds) from 

 the venous tube of X, and from that of Y, by 

 the side tubes x and y. 



h. The clamp c" of X remaining closed, open 



