CIRCULA TION . 105 



1. PaDoH. 6. PaxHxRd. 



2. PvDcH. 7. Pa^or 2 . 



3. PaxRd. 8. Pa DoH X RdXr 2 . 



4. Pv xRd. 9. Pa v. 



5. Pa xPv. 10. P o>HxRdXr 2 Xv. 



/. Grafic record of pulse tracing from the artificial circula- 

 tory system. 



With the recording apparatus used in Chapter XXI or 

 with a sphygmograph, or better, with both pieces of 

 apparatus, make tracings of the pulsations of the 

 arterial tubes "a" and b." (Fig. 17.) Com- 

 pare all tracings carefully and interpret all the 

 features of the record, differentiating the essential 

 from the nonessential, as before. 



