LX.] 



HEART-VALVES. 



289 



ADDITIONAL EXERCISES. 



8. Polygraph of Knoll and Rothe. This is a most convenient apparatus, 

 both for work in the laboratory and at the bedside. Moreover, it is so 

 arranged that two tracings can be taken simultaneously. It is made by 

 H. Rothe, Wenzelbad, Prague. It can be used to take simultaneously 



FIG. 210. II. Tracing of the cardiac impulse, the respiratory movements of the chest 

 not being arrested. 



cardiac impulse and a pulse tracing, or respiratory movements and a pulse 

 tracing, or two pulse tracings. 



Fig. 209 shows the arrangement of the apparatus. It consists of a drum 

 (F) moved by clockwork within the box D. K is a catch for setting D in 



FIG. 21 x. Showing the Method of Fixing the Receiving Tambour of Rothe's 

 Polygraph on an Artery. 



motion. M is a time-marker beating seconds. H, H are two Marey's 

 registering tambours adjustable on the stand C. B is a tambour which can 

 be fixed over an artery or over the cardiac impulse, while A is a bottle-shaped 

 caoutchouc bag which can be strapped to the body for studying the respiratory 

 movements. 



T 



