138 



EXPERIMENTAL PHARMACOLOGY 



normal and then stop the drum. Does the vagus stimula- 

 tion stop the heart? How does it affect the respiration? 

 Did you get a record from the esophagus? If so, how do 

 you explain the cause of this last record ? Could the record 

 have been caused by the respiratory movements? Could 



' .j 



Fig. 129. Four esophageal contractions, blood-pressure and respiration. The nerve was 

 stimulated (for a moment only) four times by a tetanizing current. 



