VELOCITY OF BLOOD IN VASCULAR SYSTEM 



889 



momentum of the moving mass of blood is added to the lateral pressure of the fluid. 

 A tube of this shape is connected with an artery, such as the carotid, and the tubes 



m 



J 



h' 



pl 



FIG. 389. Diagram showing the 

 construction of Chauveau's 

 hsemadromograph. 



FIG. 390. Diagram to show principle of 

 construction of Cybulski's photo-hsemata- 



chometer. 



h and h' are attached at the points c and d. These two tubes are united at their upper 

 extremities. In this case so long as the blood flows from a to 6 the fluid in h will rise 

 higher than in h', and the difference in height of the fluid in the two tubes will be pro- 



FIG. 391. 



Record of blood- velocity in the carotid artery 

 of the rabbit. (CYBULSKI.) 



portional to the velocity of the blood. A graphic record of this difference of pressure 

 is obtained by allowing a narrow beam of light to throw an image of the menisci of the 

 two columns of fluid through a slit on to a moving photographic plate. Such a record 

 is given in Fig. 391. The width of the black space at any point is proportional to the 



